Juvenile macular degeneration is accompanied by degenerative changes in the macula of the retina. The first symptoms of the disease are a bilateral decrease in vision that occurs at the age of 10-20 years.
There are several forms of Stargardt's disease, which depend on the area of distribution of the pathological process:
Through genetic analysis, it was found that juvenile macular degeneration, along with yellow-spotted fundus, is a phenotypic manifestation of the same mutation. The mode of inheritance of this pathology is usually autosomal recessive, but sometimes autosomal dominant.
The method of positional cloning established the locus of the gene, which is expressed in photoreceptors.
In Stargardt's disease, there is a pronounced accumulation of lipofuscin, which inhibits the oxidative function of lysosomes. As a result, the acidity of the fundus cells increases and their membrane integrity is disturbed.
If we are talking about the central dystrophy of Stargardt, then outwardly the macula zone looks like a "bull's eye", "broken metal", "forged bronze" or atrophy of the choroid.
In bull's eye, there is a dark central area that is surrounded by a ring of hypopigmentation. This is usually followed by another ring of hyperpigmentation. At the same time, the retinal vessels are not changed, pallor of the optic nerve head is noted on the temporal side (atrophy of nerve cells in the papillomacular bundle). Macular elevation and foveolar reflex are absent.
With yellow-spotted fundus in the posterior pole of the eye (retinal pigment epithelium) there are yellowish-white spots, the shape and size of which are different. Over time, the size and shape of the spots change, the color turns from yellow to grayish, and the boundaries are blurred.
An important role in the diagnosis of juvenile macular degeneration is played by the time of onset of symptoms (in childhood or adolescence).
Histological examination can detect an increase in pigment in the central region of the fundus. Atrophy or a combination of atrophy and hypertrophy of the retinal pigment epithelium also occurs. The substance of the macula is composed of a lipofuscin-like material.
Perimetry in patients with Stargardt's disease reveals relative or absolute scotomas. Their size depends on the timing of the disease and its prevalence. If we are talking about a yellow-spotted fundus, then the macular zone is usually not involved, so there may not be changes in the visual field.
Color anomaly most often occurs with central localization and is manifested by deuteranopia or red-green dyschromasia.
Sometimes a yellow-spotted fundus is not accompanied by a decrease in vision. However, spatial contrast sensitivity is reduced in all frequency ranges (especially in the area of medium spatial frequencies). In the central zone, within 6-10 degrees, there is no contrast sensitivity of the cone system.
In the initial stages of Stargardt's disease of the central form, a decrease in the macular electroretinogram is noted, and in the later stages it is absent. If the periphery is affected, then changes occur only in advanced stages and are manifested by a decrease in the cone and rod components of the retinogram. In this case, the symptoms in patients, as a rule, are absent, and the sharpness, visual field and color perception are within the normal range. Dark adaptation may be slightly reduced.
Fluorescein angiography with a normal background reveals areas of hypofluorescence (or its absence) with visible choriocapillaries. There is no luminescence in the macular region as a result of the accumulation of lipofuscin, which shields fluorescein. If the zones of hypofluorescence become hyperfluorescent, then this indicates atrophy of the retinal pigment epithelium.
Diagnosis can be hampered by the similarity of clinical manifestations of various types of macular dystrophies. Stargardt's disease must be distinguished from familial drusen, Kandori retinal spots, cone (rod-cone) dystrophy, dominant progressive foveal dystrophy, juvenile retinoschisis, acquired drug-induced dystrophies, vitelliform macular dystrophy.
It is impossible to carry out pathogenetically substantiated treatment, therefore, patients with juvenile macular degeneration are disabled since childhood. These patients require monitoring with the definition of the boundaries of the field of view, performing electroretinography and electrooculography.
In Stargardt's disease, there is a progressive decrease in visual function (especially in adolescence or childhood), which is a consequence of pronounced changes in the macula.
OCULAR FUNDUS (fundus oculi) - the inner surface of the eyeball visible during ophthalmoscopy: the optic disc, the retina with the central artery and central vein, and the choroid.
An extremely important area of the retina, which has the function of central vision (the highest vision in the retina), is the macula lutea (s. macula lutea) with the central fovea (fovea centralis). The yellow spot is located outside approximately 2 diameters of the disk from its temporal border; its center is slightly below the horizontal line passing through the middle of the disc. The yellow spot stands out in a darker color; it has the form of a horizontally located oval, along the edge of which often, especially at a young age, a silvery-white arc or ring is noted - a macular reflex. This light reflex occurs due to the thickening of the retina in the form of a roller around the macula. In the center of the yellow spot, a darker round spot is visible - a dimple (foveola) with a shiny dot in the middle. In older people, the yellow spot stands out less clearly, while light reflexes are usually weakly expressed or completely absent; its position in this case is judged by a darker color and the absence of blood vessels.
With conventional ophthalmoscopy, the yellow color of the spot is indistinguishable against the red background of G.; it can be seen only with ophthalmoscopy in redless light, proposed by Vogt (A. Vogt, 1913). This method is used to study the retina and optic disc. When examining with a light source devoid of red rays using a blue-green light filter, G. appears to be colored green-blue, the retinal vessels appear almost black, the yellow spot is lemon-yellow, and thin vascular branches invisible at conventional ophthalmoscopy (tsvetn. fig. 5), since short-wave rays are reflected mainly from the surface of the retina. Dimmer (F. Dimmer) found that the yellow color depends on the pigment located in the retina in the macula. In addition to redless, for ophthalmoscopy, light colored differently with the help of light filters is used.
In 1960, a comprehensive method for the study of G. by light of various spectral compositions was developed, including comparative ophthalmoscopy in blue, yellow, red, redless, yellow-green and purple light (see Ophthalmoscopy).
In the study of G. in redless and yellow-green light, you can see the course and distribution of the nerve fibers of the retina. These fibers in the form of white stripes start from the disk, bend over its edge and diverge in a fan-like fashion. Near the disc, the fibers are coarser and more clearly defined than at the periphery. Some of them follow the direction of large vessels and reach the periphery, some go to the macula, forming a papillomacular bundle. At the macula, some fibers are steeply bent, take a vertical direction, and, bordering the macula from the temporal side, are lost in it. The fibers going up and down from the disc do not participate in the formation of the papillomacular bundle; they bend and cross at an obtuse angle, and partly, without crossing, go to the periphery. The blood circulating in the vessels of the retina and choroid can be determined by fluorescein angiography (see). With its help, it is possible to clarify the causes of circulatory insufficiency in the vessels of the retina (obturation, spasm), to identify patol, processes in the macula and optic nerve that are indistinguishable during ophthalmoscopy, to differentiate tumor and inflammatory processes, early vascular changes in diabetes.
The peripheral border of G. corresponds to the jagged line (ora serrata); it has a darker color and is visible with an enlarged pupil and a maximum deviation of the eye in the corresponding direction. G.'s periphery is better seen when using a special research method, which consists in local depression of the eyeball and observation with a slit lamp (see) through a gonioscope with an appropriate mirror (see Gonioscopy).
Pathological changes in G. are caused by damage to the optic nerve, the retina and vascular membranes of the eye, as well as the boundary membrane of the vitreous body.
Ophthalmoscopically, with damage to the optic nerve, there are changes accompanied by hyperemia and edema of the optic disc - congestive nipple, ischemic disc edema, pseudocongestive nipple (see Congestive nipple), neuritis; atrophic changes (primary and secondary atrophy of the optic nerve), tumors of the optic disc and developmental anomalies (see Optic nerve). In some cases, changes are detected ophthalmoscopically only when the process, having begun somewhere in the optic nerve behind the eye, reaches the disc (retrobulbar neuritis, descending atrophy).
Patol, changes in the retina are ophthalmoscopically characterized by the appearance of diffuse opacities in it or limited white foci, hemorrhages and dyspigmentations, vascular changes. These changes are based on inflammatory (see Retinitis), circulatory-metabolic (see Retinopathy), dystrophic processes, circulatory disorders and developmental anomalies (see Retina).
Changes in the choroid, visible during ophthalmoscopy, are the result of inflammatory, degenerative, sclerotic processes, neoplasms and developmental anomalies. In most cases, inflammatory processes of the choroid are focal in nature (see Choroiditis). At the same time the pigment epithelium of a retina is involved in process owing to what in the field patol, changes there is an accumulation of lumps of a pigment. Gradually, on the site of inflammatory foci, atrophic changes occur, which are the main ophthalmoscopic sign of damage to the choroid. Some changes in G.'s, for example, the protrusion of the disc with a congestive nipple, a mottled reflex on the arteries with diabetic retinal angiopathy, are better detected with ophthalmochromoscopy. Microaneurysms in diabetic retinal angiopathy are well detected by fluorescein angiography.
Rice. 6 - 10. Pathological changes in the fundus. Rice. 6. Neurofibromatosis. Rice. 7. With tuberous sclerosis of the brain. Rice. 8. Multiple retinal angiomas. Rice. 9. With amaurotic idiocy. Rice. 10. Pseudoneuritis of the optic nerve.
Rice. 11 - 26. Rice. 11. The initial congestive nipple (the arrow indicates the arc around the nipple light reflex). Rice. 12. A pronounced congestive nipple, at the upper edge of its hemorrhage (indicated by an arrow). Rice. 13. Pseudocongestive nipple on the basis of drusen (indicated by arrows). Rice. 14. Pseudo-congestive nipple on the basis of drusen hidden in its depth (indistinguishable from a true congestive nipple). Rice. 15. Hidden druse (indicated by an arrow) (distinguishable with ophthalmochromoscopy). Rice. 16. Optic neuritis. Rice. 17. Primary (simple) atrophy of the optic nerve. Rice. 18. Secondary atrophy of the optic nerve (arrow indicates an atrophic corolla around the disc). Rice. Fig. 19. Atrophic optic disc when examined in normal light (Fig. 19 and 20 the image is enlarged). Rice. 20. An atrophic optic disc appears blue when examined in purple light. Rice. 21. Axial (axial) atrophy of the optic nerve (arrow indicates blanching of the temporal half of the disc). Rice. 22. Axial atrophy of the optic nerve when examined in purple light (pale temporal half appears blue). Rice. 23. Axial atrophy of the optic nerve when examined in yellow-green light - a symptom of a break in the pattern of nerve fibers (indicated by an arrow). Rice. 24. Obstruction of the central retinal vein (arrows indicate hemorrhage). Rice. 25. Obstruction of the branch of the central retinal vein (arrow indicates hemorrhage). Rice. 26. Obstruction of the branch of the central retinal vein when examined in redless light (arrow indicates hemorrhage).
Rice. 27-42. Rice. 27. Obstruction of the central retinal artery (arrows indicate narrowed arteries). Rice. 28. Hypertensive angiopathy of the retina (Gwist symptom). Rice. 29. Symptom of decussation of the first degree (Salus I; indicated by arrows). Rice. 30. Symptom of decussation of the second degree (Salus II; indicated by arrows). Rice. 31. Symptom of decussation of the third degree (Salus III; indicated by the arrow). Rice. 32. Hypertensive retinopathy. Rice. 33. Hypertensive retinopathy (the arrow indicates the figure of a star). Rice. 34. Ischemic edema of the optic disc. Rice. 35. Dry form of senile macular degeneration. Rice. 36. Wet form of senile macular degeneration (indicated by an arrow). Rice. 37. Ring dystrophy of the retina (the arrow indicates the shape of the ring). Rice. 38. Hypertensive neuroretinopathy (the arrow indicates the figure of a star). Rice. 39. Diabetic angiopathy of the retina. Rice. 40. Microaneurysms on examination in normal light. Rice. 41. Microaneurysms on examination in redless light (the same area as in Fig. 40). Rice. Fig. 42. Microaneurysms in fluorescein angiography. Fig. 42. 6. Neurofibromatosis. Rice. 7. With tuberous sclerosis of the brain. Rice. 8. Multiple retinal angiomas. Rice. 9. With amaurotic idiocy. Rice. 10. Pseudoneuritis of the optic nerve.
Rice. 43 - 58. Rice. 43. Simple diabetic retinopathy. Rice. 44. Proliferating diabetic retinopathy (the arrow indicates the "wonderful network" of newly formed vessels). Rice. 45. Proliferating diabetic retinopathy (the arrow indicates a strand of connective tissue). Rice. 46. Retinopathy in anemia. Rice. 47. Retinopathy in polycythemia. Rice. 48. Retinopathy in chronic lymphocytic leukemia (arrow indicates light foci bordered by hemorrhage). Rice. 49. Rheumatic retinovasculitis. Rice. 50. Disseminated tuberculous chorioretinitis (arrow indicates a light focus). Rice. 51. Disseminated tuberculous chorioretinitis on examination in blue light. Rice. 52. Central tuberculous chorioretinitis. Rice. 53. Central tuberculous chorioretinitis on examination in redless light. Rice. 54. Tuberculous retinal periphlebitis (arrows indicate muffs on veins). Rice. 55. Congenital toxoplasmic chorioretinitis (arrows indicate atrophic foci). Rice. 56 and 57. Congenital syphilitic chorioretinitis. Rice. 58. Diffuse syphilitic neuroretinitis - atrophy of the choroid.
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Name of fundus changes |
Diseases or conditions that can lead to fundus changes |
Ophthalmoscopy data |
With what pathology of the fundus it is necessary to differentiate |
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CHANGES DUE TO VASCULAR PATHOLOGY |
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Retinal angiopathy, hypertensive |
I stage of hypertension |
Narrowing of the arteries and dilatation of the retinal veins, moderately pronounced unevenness of the caliber of the arteries (functional). Mild symptom of arteriovenous decussation of the first degree (symptom of Salus I). Some patients have a corkscrew-like tortuosity of the veins of the macula (Guist's symptom - Fig. 28). Inconsistently: veiled contours of the optic disc |
Renal angiopathy of the retina. Diabetic retinal angiopathy |
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Retinal angiopathy, hypertensive, traumatic |
craniocerebral |
Expansion of the retinal veins, uneven caliber, tortuosity of the branches in the area of the macula. The arteries are narrowed, the reflex strip on them is expanded. In some places, symptoms of arteriovenous chiasm. Hemorrhages may occur. With a deterioration in the general condition, a picture of a congestive optic disc often develops. |
Hypertensive angiopathy, hypertensive neuroretinopathy |
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Retinal angiopathy, hypertensive renal |
Narrowing of the arteries, as a rule, without signs of sclerosis of the vascular wall. Occasionally symptoms of first-degree decussation (Salus I). No Gwist sign. Some patients have constrictions on the arteries, giving them the appearance of a rosary. Moderate swelling of the peripapillary retina |
Hypertensive angiopathy |
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Angiosclerosis of the retina, hypertensive |
II-III stages of hypertension |
Narrowing of the arteries and expansion of the retinal veins, uneven caliber of the arteries. Symptom of crossover of the first and second degree (Salus I and II - Fig. 29 and 30). More rarely Salus III (Fig. 31). Expansion of the reflex strip on the arteries. In places, a reflex strip of yellow color (a symptom of copper wire), in places of white color (a symptom of silver wire). Along the arteries in limited areas, lateral accompanying stripes. Expansion and tortuosity of veins. Inconstantly: retinal edema, hemorrhages in the form of single dots and strokes. Ophthalmochromoscopy: mottled reflex on the arteries when examined in redless light. In yellow-green light, uneven caliber and side accompanying stripes are better detected. In yellow light, hemorrhages are detected that are indistinguishable in ordinary light. |
Age-related angiosclerosis of the retina |
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retinopathy hypertonic |
IV stage of hypertension |
Narrowing of the arteries, their straightness. Impoverishment of the vascular tree. Uneven caliber of arteries and reflex bands. Salus I. Guist's symptom, a symptom of copper, less often silver wire. In some places accompanying stripes along the arteries. Hemorrhages. Large cotton-wool foci, as well as small dystrophic white and yellowish foci in the area of the macula. Retinal edema around the disc (Fig. 32) |
Diabetic retinopathy, retinovasculitis, hypertensive renal retinopathy |
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Neuroretinopathy hypertensive |
IV stage of hypertension (the threat of transition to a malignant form) |
Narrowing of the arteries, their straightness. Impoverishment of the vascular tree. Uneven caliber of arteries and reflex bands. Salus I. Guist symptom. A symptom of copper, less often silver wire. In some places accompanying stripes along the arteries. Severe edema of the optic disc and retina in the central region. A large number of hemorrhages and cotton wool foci. Small foci in the region of the macula may form the shape of a star (Fig. 33). Ophthalmochromoscopy: in redless light, a speckled reflex on the arteries. In red light, early signs of macular area dyspigmentation |
Hypertensive renal neuroretinopathy |
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retinopathy hypertonic renal |
Acute nephritis, chronic nephritis, toxicosis of pregnant women |
Narrowing of the arteries without signs of sclerosis of the vascular wall. Occasionally symptoms of first-degree chiasm. No Gwist sign. Some patients have constrictions on the arteries, giving them the appearance of a rosary. Moderately pronounced edema of the peripapillary retina. Cotton-wool lesions and degenerative small lesions. Hemorrhages. Severe retinal edema |
Hypertensive retinopathy |
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Neuroretinopathy, hypertensive renal |
Hypertensive |
Narrowing of the arteries without signs of sclerosis of the vascular wall. Rarely Salus I. Absence of Guist symptom. Some patients have constrictions on the arteries, giving them the appearance of a rosary. Moderately pronounced edema of the peripapillary retina. Cotton-wool foci and dystrophic small foci. Hemorrhages. Severe swelling of the retina and optic nerve (congestive nipple). Sharply narrowed arteries in some places disappear in the edematous tissue. Dry foci form the figure of a star (Fig. 38). Possible retinal detachment |
Hypertensive neuroretinopathy, congestive optic disc |
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Diabetic retinal angiopathy |
Diabetes |
Preferential changes in the veins of the retina: the veins are dilated, tortuous, their caliber is uneven. Microaneurysms are usually in the area of the macula. The arteries are little changed (arterial damage is noted in sclerotic and hypertensive forms of the disease). Single hemorrhages (Fig. 39). Ophthalmochromoscopy: in redless light, microaneurysms are revealed that are indistinguishable in ordinary light (Fig. 40 and 41). In yellow light, small and deep-seated hemorrhages become visible. Fluorescein angiography reveals a large number of microaneurysms that are indistinguishable during ophthalmoscopy (Fig. 42) |
Hypertensive angiopathy |
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retinopathy diabetic |
Diabetes |
Preferential changes in the veins of the retina: the veins are dilated, tortuous, their caliber is uneven. Microaneurysms are usually in the area of the corpus luteum. The arteries are little changed (arterial damage is observed in sclerotic and hypertensive forms of the disease). Waxy lesions of irregular shape (Fig. 43). Yellowish tinge of the fundus. In some cases, the foci form a figure encircling |
Hypertensive retinopathy, senile retinopathy |
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schey dystrophy of the retina. Some patients have white, cotton-like lesions. Large hemorrhages. Thrombosis of the central retinal vein is possible. Ophthalmochromoscopy: in blue light, a change in the color of the fundus is better detected, in redless light - microaneurysms that are indistinguishable in ordinary light. In yellow light, small and deeply located hemorrhages are visible. Fluorescein angiography reveals a large number of microaneurysms that are indistinguishable during ophthalmoscopy |
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retinopathy diabetic proliferating |
Diabetes |
Preferential changes in the veins of the retina: the veins are dilated, tortuous, their caliber is uneven. Microaneurysms are usually in the area of the macula. The arteries are little changed (arterial damage is noted in sclerotic and hypertensive forms of the disease). Wax-like foci of irregular shape. Yellowish tinge of the fundus. In some cases, the foci form a figure of girdle retinal dystrophy. Some patients have white cotton-like lesions. Large hemorrhages. Thrombosis of the central retinal vein is possible. Newly formed vessels from single branches, loops to the formation of a "wonderful network" (Fig. 44). Light moorings due to proliferation of connective tissue (Fig. 45). Possible: traction retinal detachment, vitreous hemorrhage. Ophthalmochromoscopy: redless light reveals microaneurysms that are indistinguishable in ordinary light. In yellow light, small and deep-seated hemorrhages become visible. In blue light, the change in the color of the fundus is better seen. Fluorescein angiography reveals a large number of microaneurysms, small newly formed vessels that are not distinguishable during conventional examination. |
Hypertensive retinopathy, fibroplasia of other etiologies |
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Angiosclerosis retina |
Universal angiosclerosis |
Narrowing of the arteries, their straightness. Impoverishment of the vascular tree. Uneven caliber of arteries and reflex bands. Salus I. Guist symptom. A symptom of copper, less often silver wire. In some places accompanying stripes along the arteries. Ophthalmochromoscopy: in redless light - mottled reflex on the arteries. In red light, early signs of macular area dyspigmentation |
Hypertensive angiosclerosis of the retina |
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retinopathy senile |
Aging |
Narrowing of the arteries, their straightness. Impoverishment of the vascular tree. Uneven caliber of arteries and reflex bands. Salus I. Symptom of copper, rarely silver wire. In some places accompanying stripes along the arteries. In addition, as a result of dyspigmentation, the macula acquires a mottled appearance - a dry form of macular dystrophy (Fig. 35) or an effusion appears under the retina in the area of the macula - a wet form of macular dystrophy (Kunt-Junius discoid dystrophy; Fig. 36). Small foci can form a figure of annular retinal dystrophy around the altered macula (Fig. 37). Druses of the vitreous plate are often found. Ophthalmochromoscopy: in redless light, signs of the senile form of edematous-fibroplastic syndrome of the macula (stationary reflexes, edema, cystic dystrophy, hole in the macula, fibroplasia) are better visible, in indirect red light, retinal drusen become visible, indistinguishable in ordinary light |
Hypertensive retinopathy, diabetic retinopathy, macular melanoblastoma, transudative macular degeneration in myopia |
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retinopathy traumatic |
Combination of blunt trauma of the skull and general contusion, intense compression of the trunk |
Whitish swelling of the retina. White cotton-wool-like foci of various sizes and shapes, sometimes overlapping altered vessels. A large number of hemorrhages located both in the retina and preretinally. Process regresses slowly |
Central vein thrombosis, hypertensive neuroretinopathy |
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Obstruction of the central retinal artery |
Vasomotor dystonia, hypertension, endocarditis |
A sharp narrowing of the central artery with a normal caliber of the veins. In places, collapsed arteries look like white stripes. In some areas, with incomplete closure of the lumen of the vessel, an intermittent blood flow is visible. Opacification of the retina of the central region is characteristic in the form of a light field with a cherry-red spot, located in accordance with the central fossa (Fig. 27). Possible obstruction of only one of the branches |
Central exudative chorioretinitis, retinovasculitis |
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Obstruction of the central retinal vein |
Hypertension, diabetes mellitus, arteriosclerosis, thrombophlebitis, endangiitis obliterans |
The disk is swollen, hyperemic, its borders are veiled or almost indistinguishable. The veins are dilated and tortuous. The arteries are constricted. The retina is edematous, especially around the disc and in the central region. Possible cystic macular edema. A large number of hemorrhages are characteristic: around the disk they can be located like tongues of Flame (Fig. 24), and on the rest of the fundus in the form of smears, spots, strokes, splashes and dots. White cotton-like lesions are also observed. If one of the branches of the central vein is obstructed, hemorrhages, edema and white lesions are located, respectively, in the affected area (Fig. 25). Ophthalmochromoscopy: in redless light, retinal edema, cystic macular degeneration and white foci are better detected (Fig. 26) |
Congestive optic disc, hemorrhagic retinovasculitis |
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Ischemic papilledema |
Hypertension, atherosclerosis, obliterating endarteritis, rheumatic vasculitis, cervical osteochondrosis |
Pale edema of the optic disc, giving it the appearance of a moderately protruding congestive nipple with a milky white or yellowish color (Fig. 34). Arteries are sharply narrowed. The veins are dilated. There may be hemorrhages that are located both on the disc and around it. Characteristic is the absence of an arc reflex near the disk. In acute edema, optic nerve atrophy usually develops after 2-3 weeks. |
congestive optic disc, optic neuritis, pseudocongestive optic disc |
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congested nipple |
Brain tumor, other diseases c. n. s., causing an increase in intracranial pressure (inflammatory diseases of the brain and its membranes, skull deformity, etc.), general diseases (hypertension, diseases of the kidneys, blood, etc.), diseases of the orbit and eyes |
There are initial, pronounced, pronounced congestive nipple and congestive nipple in the stage of atrophy. In the initial stage, partial veiling of the boundaries of the optic nerve head, moderate varicose veins, and retinal edema are visible in places. Around the disc is an arc peripapillary light reflex (Fig. 11). A small protrusion of the disc is better detected with ophthalmochromoscopy and biomicroscopy. With a pronounced congestive nipple, the disc is enlarged in size and stands in the vitreous body by 2-7 D (0.6-2 mm), its borders are veiled, the veins are dilated and tortuous, the arteries are narrowed. Vessels are bent over the edge of the disk and in some places seem to be interrupted in the edematous tissue of the retina. Hemorrhages on the disc and adjacent retina are possible (Fig. 12). With a pronounced congestive nipple, the protrusion of the disc reaches 5--7 D (1.5-2 mm) or more, the diameter of the disc is significantly increased, there are more hemorrhages, the borders of the disc are blurred. The retina is edematous, small light foci are visible in it, sometimes forming a star figure in the area of the macula. In the stage of atrophy, the disc becomes pale, its edema decreases, the arteries narrow, there are fewer small branches, and hemorrhages resolve. The light reflex near the disk disappears. Later on, optic atrophy develops. |
Pseudocongestive nipple, optic neuritis, ischemic optic edema, obstruction of the central retinal vein, neuroretinopathy |
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optic nerve atrophy |
Diseases of the brain and its membranes, multiple sclerosis, intoxication, hypertension, atherosclerosis, injuries, hereditary diseases |
A constant symptom is blanching of the optic disc. The vessels are constricted. The boundaries of the disk can be clear - primary (simple) atrophy (Fig. 17) or veiled - secondary atrophy. With secondary atrophy, changes in the fundus around the disc can be observed (Fig. 18). Ophthalmochromoscopy: in purple light, the white disc becomes blue (Fig. 19 and 20) |
Paleness of the optic disc in blood diseases, constitutional discoloration of the disc |
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CHANGES DURING INFLAMMATORY PROCESSES |
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Tuberculous retinal periphlebitis |
Incomplete, intrathoracic tuberculosis |
Recurrent, often massive vitreous hemorrhages. After resorption of hemorrhages, light, slightly protruding foci, located, as a rule, on the periphery of the fundus, fibrous bands become visible. White accompanying stripes are noted along the veins. Muffs on the veins. Violation of the normal course and caliber of the veins. These changes are better seen in redless light (Fig. 54) |
Periflebitis of various etiologies |
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Optic neuritis |
Inflammatory diseases of the brain and its membranes, general infections (flu, malaria, tuberculosis, brucellosis), toxic-allergic diseases, local foci of inflammation (paranasal sinuses, nasopharynx, mouth), inflammation of the membranes of the eye and orbit |
The optic disc is hyperemic, its borders are veiled. Arteries are not changed, veins and capillaries are dilated (Fig. 16). There may be hemorrhages on the disc, less often white exudative foci. Hemorrhages and accumulations of exudate are also noted near the disk on the retina. In more rare cases, there may be severe disc edema |
Congestive nipple, pseudoneuritis, ischemic optic edema |
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Optic neuritis retrobulbar |
Multiple sclerosis, diseases of the paranasal sinuses and orbit, common infectious diseases (flu, etc.) and intoxication (tobacco-alcohol, etc.) |
Characteristic is the absence of changes in the fundus with reduced central vision and the presence of a central scotoma. When examining in redless light, the veiled contours of the disk, its edema and arc reflex. If the focus of inflammation is located near the eyeball, then the process proceeds according to the type of optic neuritis |
Congestive nipple, optic neuritis, ischemic edema, onset of descending optic nerve atrophy in tumors of the frontal lobe of the brain |
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Neuroretinitis syphilitic diffuse |
Acquired syphilis (II-III stage) |
Stormy start. Severe diffuse edema of the retina and optic nerve. Opacification of the posterior vitreous. Later, extensive atrophy of the choroid, retina and optic nerve develops. The pigment layer is preserved only in the area of the macula (Fig. 58) |
Diffuse chorioretinitis of tuberculosis, toxoplasmosis and other etiologies |
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Chorioretinitis syphilitic congenital |
congenital syphilis |
There are three main types of fundus changes. The first, the most common, is characterized by small pigmented clumps, alternating with small light foci. Because of the characteristic appearance, it was called "salt and pepper" retinitis (Fig. 56). Ch. is amazed. arr. the periphery of the bottom of the eye, but the foci can also be located in the central region. The second type is large pigmented atrophic foci or light pink atrophic foci, sometimes merging with each other (Fig. 57). The foci are located on the extreme periphery of the fundus. The third type proceeds as retinitis pigmentosa |
Congenital dystrophies of the fundus of the eye, retinitis pigmentosa of another etiology |
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Chorioretinitis toxoplasmosis congenital |
congenital toxoplasmosis |
Mostly in the central region of the bottom of the eye, light foci of various sizes, round or oval, with clear boundaries. Characteristic is the accumulation in the foci, especially along the edges, of a significant amount of dark pigment. Often there is a large central focus, resembling a congenital coloboma of the choroid (Fig. 55). There may also be optic nerve atrophy, retinal fibroplasia and accumulation of connective tissue in the vitreous body - pseudoglioma |
Disseminated chorioretinitis of tuberculous and other etiologies, retinoblastoma |
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Chorioretinitis toxoplasmosis acquired |
Acquired Toxoplasmosis |
The disease can proceed according to the type of central retinitis or chorioretinitis with the formation of prominent grayish foci surrounded by hemorrhages. Perhaps the course of the type of exudative neuroretinitis or diffuse chorioretinitis. Primary and secondary lesions of the retinal vessels are often noted. |
Chorioretinitis of tuberculous and other etiologies |
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Disseminated tuberculous chorioretinitis - metastatic focal lesions of the choroid proper with involvement of the retina |
Tuberculosis of all localizations |
Foci, as a rule, of different age, located in the posterior part of the fundus outside the macula. Fresh ones are yellowish or whitish in color with veiled outlines and sometimes bordered with hemorrhage. The old ones are lighter with clear boundaries and accumulations of pigment, often forming a corolla. Small clumps of pigment are visible between the foci (Fig. 50). Ophthalmochromoscopy: in blue light, old foci are less clearly visible, fresh ones are better detected (Fig. 51) |
Disseminated chorioretinitis of other etiology (Toxoplasmosis, viral and other infections) |
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Chorioretinitis tuberculous central |
Tuberculosis of all localizations |
In the region of the macula, there is a relatively large, prominent exudative focus of yellowish or gray-slate color with perifocal retinal edema (exudative form). Around the focus, hemorrhages are possible in the form of spots or a corolla - an exudative-hemorrhagic form (Fig. 52). Perifocal edema and the by-pass beam reflexes caused by it are seen better in redless light (Fig. 53) |
Transudative macular degeneration, central granulomatous process in syphilis, brucellosis, malaria, etc. |
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Retinochoriovasculitis with perivascular infiltration and hyalinosis of the vessel wall |
lupus erythematosus |
Uneven caliber of the retinal arteries, in places their obliteration, microaneurysms, hemorrhages, cotton-wool foci, disc edema. The outcome may be retinal fibrosis. Fibrosis of the choroid. Atrophy of the optic nerves |
Hypertensive retinopathy, diabetic retinopathy |
|
Atrophy of the optic nerve, axial |
Multiple sclerosis and other diseases of c. n. s., diseases of the paranasal sinuses, common infections and intoxications |
Paleness of the temporal half of the optic disc with increased clarity of its temporal border (Fig. 21). Narrowing of the arteries. Ophthalmochromoscopic picture: in purple light, the temporal half of the disk is blue (Fig. 22), in yellow-green - a symptom of a break in the pattern of nerve fibers (Fig. 23). With fluorescein angiography - a symptom of a striped frame |
Severe physiological excavation of the optic disc |
|
Optic nerve atrophy, syphilitic |
Dorsal tabes |
The optic disc is pale with a characteristic grayish tint. Disc borders are clear. Arteries are narrowed only in advanced cases. The process is usually two-way. |
Simple atrophy of the optic nerve of another etiology |
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Retinal nodular periarteritis |
Nodular periarteritis |
Yellowish-brown nodules on arteries. Hemorrhages. Edema of the retina and optic disc. Some patients have thrombosis of the retinal arteries. In the presence of hypertensive or renal syndrome, the development of malignant neuroretinopathy and serous retinal detachment is possible. |
Rheumatic retinovasculitis, hypertensive neuroretinopathy |
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Retinovasculitis rheumatic |
Rheumatism |
Along the retinal vessels there are lateral accompanying stripes, in some places a grayish color of the sleeve. In the retina along the vessels there are small grayish foci. With the involvement of several vessels, large white effusion foci are visible near the optic disc, overlapping the vascular bundle (Fig. 49). Possible "hemorrhages and swelling of the retina |
Retinovasculitis with nodular periarteritis |
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CHANGES IN BLOOD DISEASES |
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Retinopathy with anemia |
Anemias: aplastic, hypochromic, pernicious, secondary |
The color of the fundus is pale pink. The optic disc is discolored. The veins are dilated and tortuous. The difference in color of veins and arteries is reduced. Intermittent changes: in purple light, blue optic disc and fundus. With a decrease in the number of red blood cells below 50% of the norm, in addition, hemorrhages in the form of strokes, round spots and flames. Characteristic are hemorrhages with a white center (Fig. 46). White cottony patches. There may be peripapillary retinal edema around the disc. With a more severe course of the process, preretinal hemorrhages and hemorrhages in the vitreous body. Congested nipples, rarely neuritis. Atrophy of the optic nerve. Possible retinal detachment |
Optic atrophy of other etiology, congestive nipple, optic neuritis |
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Retinopathy in chronic myelogenous leukemia |
Chronic myeloid leukemia |
The color of the fundus is orange or yellow. The veins are dilated. With a severe course of the hemorrhage process, some of them with a white center. Possible hyperemia of the disk, swelling of it and the peripapillary retina. Sometimes cottony patches |
Optic neuritis |
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Retinopathy in acute leukemia |
Acute leukemia |
Pale background of the fundus. Arteries are discolored. The veins are dilated. Polymorphic hemorrhages. The optic disc is pale, the contours of the disc are veiled. Ophthalmochromoscopy: when examined in purple light, the optic disc is blue-purple. When examined in yellow-green light, the preserved pattern of nerve fibers is visible. |
Congested nipple in the stage of atrophy |
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Retinopathy in chronic lymphocytic leukemia |
Chronic lymphocytic leukemia |
The disk acquires a yellowish tint, its borders are veiled. The arteries are constricted. The veins are dilated and tortuous. Numerous hemorrhages. Some patients have pale yellow foci located along the periphery of the fundus. The foci may be bordered by hemorrhage (Fig. 48) |
Ascending optic nerve atrophy, chorioretinitis |
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Retinopathy in polycythemia |
Polycythemia |
The background of the fundus is dark red with a bluish tint. The veins are cyanotic, sharply dilated and tortuous (Fig. 47), the arteries almost do not differ in color from the veins. With the progression of the disease, in addition, small hemorrhages |
pseudoneuritis |
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CHANGES IN OTHER DISEASES |
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Choroid angioma |
Encephalotrigeminal neuroangiomatosis (Sturge-Weber disease) |
Glaucomatous excavation of the optic disc. Often, myelin fibers are visible near the disc. The veins are dilated and tortuous. Possible angioma of the choroid. In some cases, peripapillary squamous retinal detachment |
Primary glaucoma, choroid melanoblastoma |
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Retinal angiomatosis |
Retino-cerebellovisceral angiomatosis (Hippel-Lindau disease) |
Angiomas in the form of rounded glomeruli of various sizes - from small to large nodes exceeding the diameter of the optic nerve head. A pair (vein, artery) of dilated, tortuous vessels approaches each tangle (Fig. 8). Newly formed vessels and focal changes in the retina are observed |
Racemose aneurysms of retinal vessels. Proliferating diabetic retinopathy |
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retinal dystrophy |
Amaurotic |
In the early childhood form, characteristic changes in the central part are found at the bottom of the eye in the form of a grayish-white area with a bright red spot in the center, located corresponding to the central fossa (Fig. 9). With a late childhood form, atrophy of the optic nerve develops |
Pigmentary degeneration of the retina, changes in the fundus of the eye with reticuloendothelial sphingomyelosis |
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Atypical retinal dystrophy |
Laurence-Moon-Biedl syndrome |
Accumulations of pigment in the form of small rounded or striped foci. In 15% - accumulations of the type of bone bodies typical of pigmentary dystrophy. In most patients, along with pigment clusters, whitish small foci are found. |
Pigmentary retinal dystrophy |
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Tumor-like formations of the optic disc and retina of the hamartoma type |
Neurofibromatosis (Recklinghausen's disease) |
On the optic disc there are tumor-like formations of a whitish or yellowish color with a shiny surface (Fig. 6). Small nodules and plaques of yellow or white color are visible on the retina |
Changes in the fundus of the eye in tuberous sclerosis |
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Tuberous sclerosis of the brain (Bourneville disease) |
Hemorrhages are possible on the retina, resembling mulberries (Fig. 7). Similar growths are possible on the optic nerve head. There may be obvious and hidden drusen of the optic disc |
Fundus changes in neurofibromatosis |
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pseudoneuritis |
High farsightedness, delayed embryonic stage of optic nerve development |
The optic disc is hyperemic, its borders are veiled. Pronounced tortuosity of vessels (Fig. 10). The caliber of the arteries is not changed, atypical course of the vessels and other anomalies of their development are often observed |
Optic neuritis |
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Pseudocongestive nipple |
Drusen of the optic nerve head, constitutional features of the structure of the optic nerve head |
The pseudocongestive nipple, caused by obvious drusen, has a bumpy appearance, its edges are scalloped, the caliber of the vessels is not changed (Fig. 13). With a pseudocongestive nipple due to hidden drusen (Fig. 14), the correct diagnosis can be made with biomicroscopy or ophthalmochromoscopy: in indirect red light, latent drusen become visible as rounded luminous formations (Fig. 15) |
Congestive nipple, subtraction cones in myopia, ischemic optic nerve edema |
Bibliography Arkhangelsky VN Morphological bases of ophthalmic diagnostics, M., 1960; Berezinskaya D. I. Fundamentals of ophthalmoscopic diagnosis, M., 1960; Vodovozov A. M. Ophthalmochromoscopy, Atlas, M., 1969, bibliogr.; Volkov V. V., Gorban A. I. and Dzhaliashvili O. A. Clinical examination of the eye with the help of instruments, L., 1971; Multi-volume guide to eye diseases, ed. V. N. Arkhangelsky, vol. 1, book. 2, p. 16, M., 1962, bibliography; Plitas P. S. Ophthalmoscopic atlas, M., 1960; Radzikhovsky B.A. Ophthalmoscopic diagnostics (with an ophthalmoscopic atlas), Chernivtsi, 1957; Radnot M. Atlas of eye diseases, trans. from Hungarian., vol. 2, Budapest, 1963; Shulpina N. B. Biomicroscopy of the eye, M., 1974, bibliogr.; Der Augenarzt, hrsg. y. K. Velhagen, Bd 1, S. 559, Lpz., 1969, Bibliogr.; System of ophthalmology, ed. by S. Duke Elder, v. 5, L., 1970; Trevor-Roper P.D. The eye and its disorders, Oxford, 1974.
H. K. Ivanov; tabular compiler. A. M. Vodovozov.
16-05-2012, 21:14
a) Use of stereoscopic perceptions. Binocular assessment of the relief of the fundus and the deep structure of ophthalmoscopic translucent objects is possible using BO-58 and SHL-56. For stereoscopic perception, it is necessary that the studied area of the fundus be seen simultaneously by each eye of the doctor and that both of these images do not double, but merge into one, three-dimensional image. Recommendations on the technique of such a study were given in the previous section. Persons deprived of binocular vision, naturally, cannot use this technique.
b) Using instrument refocusing. A qualitative assessment of the volumetric structure of an object by the clarity of the image when the device is refocused follows from the tuning rules for BO-58 and SL-56. As mentioned, the depth of field of the BO binocular attachment and the SL microscope (at medium and high magnifications) is small. This requires refocusing of the eyepieces (by rotating them) or the entire slit lamp, even with a slight change in the relief of the fundus in the newly examined area. Moreover, even in normal relief, the fine adjustment to the retinal vessels should be somewhat different from the adjustment necessary for a clear vision of the foci in the pigment epithelium layer. By tuning the instruments to one or another object, one can judge the relative location of these objects in depth.
c) Evaluation of the nature of parallax shifts in the image of the details of the fundus. With a sufficiently wide pupil, the BO can be moved slightly horizontally and vertically without loss of binocularity and without reducing the quality of fundus illumination. To a certain extent, this applies to both the electro-ophthalmoscope and the slit lamp, which creates the prerequisites for assessing the relief and volumetric structure of objects in the fundus by analyzing the parallax shifts of their images. The technique is similar to the effect of unequal angular displacements of objects flashing in front of the passenger in the window of a moving train: the closer the object is located, the faster its apparent displacement. A similar situation arises when the observer is armed with an ophthalmoscope (slit lamp), and the object of observation is the details of the fundus. It is necessary to remember the basic rule of parallax displacements of the ophthalmoscopic picture: the closer an object is located in the fundus to the observer, the faster it shifts when the device moves. Therefore, if the visible movement of the object is faster than the displacement of the entire ophthalmoscopic picture, then the object rises above the level of the rest of the fundus, and, conversely, if in its movement the image of the object seems to lag behind the shift of the background picture, then the object is located deeper than the level of the fundus .
In order to use this effect for diagnostic purposes, the following conditions are required.
Firstly, the details of the fundus, located at different levels, should be visible in the field of view of the ophthalmoscope (slit lamp) at the same time.
Secondly, since the amplitude of shifts in the ophthalmoscopic picture is small, it is necessary to move the device in such directions that can provide the clearest deformation of the observed picture. If it is necessary to assess the mutual level of two objects lying side by side, it is more visual to shift the device in the direction of the segment, which can mentally connect these two objects (Fig. 100, II, III, and not IV, V).
Rice. 100. Mutual parallax displacements of images of two conditional objects on the fundus - a square and a circle - at various instrument shifts (II-V) from the initial position (I). Other explanations in the text.
If we are talking about a single object of a linear shape that crosses the area of the fundus where a change in relief is expected (a vessel on the edge of the optic nerve head, etc.), then the device will be more visually displaced not along, but across the linear object (Fig. 101 , I, II, III).
Rice. 101. Schemes of parallax displacements of the vessel image at the edge of the optic disc.
A - with a sharp, step-like level difference ("glaucoma excavation"); B - with a smooth change in relief ("stagnant nipple"). 1 - part of the optic disc; 2-vessel.
Thirdly, the main attention should be paid not to the comparison of static pictures of the fundus at two positions of the device, but to the change in the mutual position of the details of the fundus during the movement of the device itself. Therefore, the shift of the ophthalmoscope (slit lamp) must be carried out quickly enough, in the form of "wiggles". In the case when you need to catch a slight parallax, we advise you to look a little past the object. The paramacular zone of the retina better recognizes moving objects.
You can check out the parallax effect on a paper model if you like.
Draw clear lines on several strips of paper, and then bend them as shown in fig. 102.
Rice. 102. Scheme of manufacturing models for the exercise on the estimation of parallactic displacements.
1 - a strip of paper with a line drawn on it; 2-7 - models of excavations and protrusions of the fundus areas (side view).
Lay these curved strips on a well-lit table surface. Covering one eye and gently shaking the +13.0 D loupe over the paper across the black line, you will become familiar with the main types of misalignment encountered. However, keep in mind that on a paper model, those parts that are farther from you will move faster.
Therefore, such exercises are purely indicative, although quite visual.
Finally, answer Security Question 42.
d) Analysis of shadow pictures. In some forms of pathology, moving or stationary shadows can be seen on the surface of the fundus.
First of all, one should dwell on their variety, which associated with the appearance of floating opacities in front of the retina- in the vitreous body or on its posterior limiting membrane (with its detachment). To detect them during the study on BO, the patient is offered to change the orientation of the gaze and quickly return the eye to its original position. Sometimes not immediately, but after a few seconds, it is possible to notice delicate shadow stripes and spots that “swim” along the considered area of the fundus.
The second source of shadow formation at the bottom of the eye are terminal branches of the retinal vessels. With retinal edema (without clouding) or with limited flat detachment, especially in the paramacular zone, the distance between the retinal surface and the pigment epithelium layer increases. If the lines of illumination and observation in the device do not coincide, which also takes place in the BO in ShL-56 (with the illuminator lateral), then the shadows cast by the vessels on the pigment epithelium are removed from under the projection of the vessels themselves and become noticeable (Fig. 103 ).
Rice. 103. Formation of shadows from retinal vessels.
1 - end vessels; 2 - edema zone; 3 - shadows from the vessels (marked with a dotted line).
The third version of the shadow paintings occurs on the projection of holes in the retina, if their edges are separated from the pigment epithelium. Shadows are more visible when the illuminator is shifted, when the angle of the incident rays changes during the inspection (Fig. 104, I, II, III).
Rice. 104. Formation of a shadow (2) within a perforated retinal defect with protruding edges (1).
The appearance of such a mobile crescent-shaped shadow within the focus, suspicious for rupture, undoubtedly indicates a defect in the retina, at least in its inner layers.
Because the this is a pretty rare picture., we recommend that you get acquainted with it on a simple model. Bend a strip of paper 8-10 cm long in the form of the letter "P" so that each side is 2-3 cm long. Make a hole with a diameter of 5-8 mm in the transverse part. Place the model on a piece of white paper so that the hole is "hanging" above the surface. Try to illuminate the model from above with a specular ophthalmoscope. Through the ophthalmoscope, you will see how, with slight turns of the mirror, a shadow will appear on the side of the visible contours of the hole, indicating the presence of a gap between the edges of the hole and the underlying sheet of paper.
e) Analysis of retinal reflexes. With ophthalmoscopy, especially in young people, there are peculiar reflections from the fundus of the eye - “retinal reflexes”. They are due to the appearance of the inner limiting membrane of the retina: on this interface, conditions arise for the mirror reflection of the light source, which, in essence, is the retinal reflex. Obviously, the brightness of this reflection should primarily depend on the reflective properties of the inner boundary membrane. For a correct understanding of the nature of polymorphic retinal reflexes, it is also necessary to take into account the presence of irregularities on the inner surface of the fundus. As can be seen from fig. 105,
Rice. 105. Significance of the slope of the retinal surface in the formation of the retinal reflex (diagram, top view).
1-light source; 2-mirror of the ophthalmoscope; 3 - the examined eye; 4 - eye of the observer.
the beam of light reflected from the retina can leave the pupil and enter the eye of the observer only when the slope of the reflective surface does not exceed a certain value. The wider the pupil, the more inclined areas of the retina you can see the brilliance of the reflex.
Having understood the nature of these reflexes, one can draw valuable conclusions regarding the topography of the most insignificant irregularities in the retina and, in particular, determine the shape, character (convexity or concavity) and the degree of curvature of the relief deformation.
Rice. 106. Influence of the shape of the fundus surface on the appearance of the retinal reflex (scheme). Explanation in the text.
illustrates how the shape of the retinal surface affects the appearance of retinal reflexes. So, if the reflex has the form of a wide spot of a bizarre shape (I), then the surface in this place approaches a flat one. In the case when the reflection has the form of a point or a small spot (II), the surface is spherical. If the reflex looks like a line or strip (III) - the surface is cylindrical. An oval-shaped reflex (IV) indicates a spherical-cylindrical surface, more curved in the direction of the oval diameter. If the reflection is triangular (V) - the surface has the shape of a cone. Finally, when the reflex resembles a ring (VI), a toroidal surface, like the surface of a donut or its imprint.
An essential section of this type of clarifying study is analysis of the displacement of reflexes when changing the direction of the illumination of the fundus. During ophthalmoscopy with the help of BO, when the analysis of reflections can be carried out with maximum completeness, or when working with EO and CL, illumination shifts are created by lateral or vertical oscillations of the entire device (as in the method of determining levels by parallax). It must be remembered that in the last two cases, when the fundus is observed in direct view, the displacement of the reflexes will have a character opposite to that described below.
On fig. 107
Rice. 107. Scheme of displacement of retinal reflexes during reverse ophthalmoscopy.
1 - light source (solid arrow shows the direction of its displacement); 2- reflective surface; 3-retinal reflex (dotted arrow indicates the direction of its apparent shift). I, II, III are explained in the text.
it is shown how retinal reflexes are displaced during reverse ophthalmoscopy, depending on the nature of the retinal irregularity. The reflex is shifted in the same direction as the large ophthalmoscope, which means that the surface of the retina is concave in the direction of the shift (I). The reflex is shifted in the opposite direction - the surface of the retina in the direction of the shift has a bulge (II). Nearby reflexes are simultaneously shifted in different directions and, when approached, merge into one reflex - the surface of the retina in the direction of the shift of the device is S-shaped (the bulge borders on the concavity - III). If the illumination is shifted first in one and then in the other mutually perpendicular directions and the reflection in both cases is shifted to the same side with respect to the shift of the device (either together with it, or vice versa) - means the surface of the retina has a general positive or negative curvature(bulge or fossa). If, under the same shifts in illumination, the reflex shifts in different directions (in one case - in the direction of displacement of the device, in the other - vice versa), then the surface of the retina has a "saddle" shape.
The degree of curvature of the surface of the fundus area is assessed by the size and persistence of the reflex. The dependence here is as follows: the steeper the surface of the retina is curved in the direction of movement of the device, the smaller the area of the reflex, the more stable it is and the less it shifts along the fundus (and vice versa).
A few words about normal retinal reflexes. It is known that their severity depends on age. For newborns, the absence of central reflexes is typical. In children and in adolescence, they acquire maximum distinctness, and then become less and less bright, and by the age of 60 they almost completely disappear. The age-related weakening of the reflexes is associated with smoothing of the irregularities of the retina and with a change in the optical properties of its inner limiting membrane, which begins to reflect an ever smaller part of the rays incident on it.
Normally, the following types of retinal reflexes can be observed (Fig. 108, 1-5):
Rice. 108. Normal reflexes from the fundus.
A - scheme of the ophthalmoscopic picture (explanation in the text); B - reconstruction of a horizontal section of the posterior part of the eye (arrow down - places of formation of "concave" reflexes; arrow up - places of formation of "convex" reflexes).
1. Foveolar reflex. It is formed by the central fovea of the retina and is a real and reduced image of the light source in the concave "mirror" of the foveola.
2. Macular reflex(or "shaft-reflex"). This is an annular reflex that borders the area of the macula. It owes its appearance to the roller-like thickening of the retina due to the growth of layers of ganglion cells, displaced from the fovea to the periphery. The reflex is formed by the convex surface of the thickening; its width depends on the degree of curvature of this bulge, and its size depends on the size of the macula.
3. Paramacular reflex. We call this term a wide annular reflex, which is located outward from the shaft reflex. Often it is not visible at the same time around the entire circumference. The reflex is formed by the concavity of the retina at the point of transition of the macular shaft to its normal level. The more gently this transition occurs, the wider the ring of the paramacular reflex.
With shifts in illumination, both annular reflexes shift in mutually opposite directions, merging into one wide reflex on the outer clivus of the macular shaft when moving in the opposite direction.
4. parafoveolar reflex. So we call the triangular reflex, which is often observed within the macular zone. The top of this narrow light triangle is located in the foveola; the base faces the shaft-reflex and can merge with it when the device moves. This reflex arises from the inner clivus of the macular shaft when it has the shape of a flat funnel.
5. Planar retinal reflexes. They look like polymorphic, partially merging shiny spots and are caused by other physiological irregularities of the retina (protrusion of the inner limiting membrane by large retinal vessels; retinal deformity at the oblique entrance of the optic nerve; retraction of its level at the temporal, lower edge of the disk; relative thickening of the retina on the nasal side yellow spot, etc.) Planar reflections, which are formed, as a rule, by surfaces with slight curvature, are extremely unstable: they change their appearance, disappear or appear at the slightest shifts in illumination. We consider it appropriate to emphasize the reverse side of this phenomenon. These reflexes with their play clearly register dynamic fluctuations in the level of the retina associated with pulsation in the system of its central arteriole. The phenomenon of the retinal "pulse" is noticeable by reflexes in stationary lighting. It may be useful in the study of vascular pathology of the fundus.
Despite clinical diversity, pathology of retinal reflexes can be reduced to two main manifestations- to the complete or partial disappearance of the normal reflex and the appearance of atypical (“pathological” according to Vodovozov) reflexes. It should be emphasized that the disappearance of reflexes can be associated with pathology only if the normal age sequence of their extinction is perverted (usually planar reflexes disappear first, then macular reflexes, and last of all, the foveolar reflex).
For the correct interpretation of the ophthalmoscopic picture, it is advisable to know the reasons underlying the pathological disappearance of normal reflexes. There are several such reasons.
1. Retinal edema, which violates the "mirror" of the inner boundary membrane. This reason may explain the loss of reflexes in areas of retinal opacity (with traumatic maculitis, central serous retinopathy, etc.). Apparently, the extinction of retinal reflexes in flat retinal detachment can also be attributed here.
2. Local retinal atrophy and the associated smoothing of its physiological irregularities (absence or irregularity of central reflexes in various macular degenerations).
3. Rupture of the inner limiting membrane. This moment determines the disappearance of the foveolar reflex in perforated macular defects, including non-through ones.
4. Presence of preretinal changes that interfere with the reflection of light from the retina or significantly weaken it (clouding in the posterior layers of the vitreous body, proliferation of connective tissue along the retina, preretinal hemorrhages, etc.).
Pathological reflexes, being fairly standard in form, clinically very diverse. Ring reflexes can be observed around the focus of serous central retinopathy or at the top of its prominating part, as well as around protruding "hidden" chorioretinal foci and on the tissue of the congestive nipple. The arc reflex occurs along the edge of the congestive nipple, at the nasal edge of the optic disc in myopia, along the edge of true myopic staphyloma, and also along the edge of tumors, subretinal and intraretinal hemorrhages that protrude the surface of the retina. The presence of this reflex makes it possible, in particular, to differentiate hemorrhage under the internal limiting membrane from preretinal hemorrhage, which cannot be done in any other way (retinal vessels are covered with blood in both cases).
Single point reflex appears on top of "hidden", but at least slightly protruding chorioretinal foci; multiple closely spaced point reflexes occur in areas of planar cicatricial deformation of the retinal surface (“glow of crumpled foil”). Narrow paired linear reflexes, fanning out from the area of scarring or local edema in the retina, are a reflection from the surfaces of traction folds of the entire thickness of the retina or only the inner limiting membrane. The appearance of a triangular reflex indicates cone-shaped protrusions or retractions of the retina (a variant of the structure of the focus in central serous retinopathy, myopic staphyloma, etc.).
There are few reflections associated with the appearance of an additional reflective substance. They must be attributed: 1) "projector reflexes" - reflections from crystalline inclusions in the retina, from drusen of the optic nerve head, etc .; 2) sometimes visible, albeit very weak, reflection from the posterior, compacted surface of the detached vitreous body and 3) "double dot reflexes" from the anterior and posterior walls of intraretinal cysts, if they protrude the surface of the retina (rarely observed, but they can reliably exclude a retinal defect ).
For training in this type of study we recommend paying attention to light glare, which are formed by the smooth surfaces of many objects that surround us in everyday life. This is not a very flat floor, covered with linoleum, and walls painted with oil paint, and cases of fountain pens, spoons, various pipes and the like. When analyzing these highlights, pay attention not to the fine structure of the surface, which “appears” within the shiny zone (such a recommendation was given in the first chapter), but to the shape of the light spots, their size, stability when the light source (or your head) is shifted , which basically gives the same effect). Try to evaluate also the direction of the “reflex” shifts, which makes it possible to distinguish a concave surface from a convex one. Remember only that under experimental conditions the laws of reverse ophthalmoscopy do not apply; therefore, the direction of the shifts will be natural, that is, opposite to that given earlier in the list of rules for the analysis of retinal reflexes.
In conclusion, examine patients using the recommendations outlined in this section. Try to draw on the schematic "sections" from the posterior part of the eyeball the identified features of the relief of the fundus. But before that, solve the two control problems (No. 43 and 44) placed at the end of the chapter.
f) Use of direct focal illumination. A slit lamp is suitable for studying the structure of ophthalmoscopic objects in direct focal light. It is easy to calculate that with an average thickness of the retina, say, 0.3 mm and illumination at an angle of 5-6 ° (for examining the fundus, this is already a large angle), the visible width of its optical section will be about 0.03 mm, that is a value about 30 times smaller than the usual cut from the cornea, viewed under the same magnification. Under these conditions, serial copies of ShchL-56 do not allow obtaining a clearly differentiated optical section from a normal retina. Despite the fact that the cut plane actually escapes observation, some conclusions about the relief of the fundus can still be made on the basis of an analysis of the general shape of a narrow band of light on the surface of the retina. This strip is, in essence, the front edge of an almost invisible cut. The most typical variants of the observed patterns are shown in Figs. 109.
Rice. 109. Evaluation of the relief of the fundus by the shape of the focal light strip (1) on its surface (illuminator on the left). Explanation in the text.
Diagram I shows marginal excavation of the optic disc, judging by the degree of break in the light strip, it is very deep. Scheme II shows the course of the light strip in the opposite condition - moderate bulging of the optic nerve head.
The shape of the strip of light is similar with a slight elevation of the fundus in the area of the pigmented neoplasm (Scheme III). Finally, Scheme IV shows the fundus pattern of a retinal detachment with two areas suspected of tearing.
Right "hole" blind, since the strip of light, passing over it, does not disappear and is not deformed; left - a true break (a strip of light in its zone is interrupted).
Deformations of the light strip, similar to those shown in fig. 109, due to the small angle of incidence of light are insignificant. To notice them you need to be able to mentally compare the real course of the strip with the one that it would have to have with a geometrically correct continuation within its entire length (along a straight line or along an arc).
What to do if the illuminator cannot be moved aside even at a small angle (narrow pupil, light beam distortion, etc.), but for some reason it is desirable to resort to evaluating the fundus relief using ShL-56? With the middle location of the illuminator, it can help, in addition to the stereoscopic perception of the picture, evaluation of the dynamics of the width of the light strip when adjusting the device to different levels of the object. Recall that the depth of the strictly focal zone of the ShL-56 illuminator is small and amounts to fractions of a millimeter. During biomicroscopy of the anterior part of the eye, this circumstance upset us, since it did not allow us to “wander” with the microscope along the plane of the optical section of objects extended in depth. With biomicroophthalmoscopy, the second, positive side of this moment is revealed. If the sections of the prefocal and postfocal beams of light expand rapidly as the screen moves away from the focus, then any unevenness of the fundus will affect the width and clarity of the strip of light in different areas. Moreover, by shifting the lamp along the observation axis, it is possible to sequentially bring the focus of illumination, that is, the narrowest strip of light, to the prominent or "sinking" areas of the fundus relief. Thus, it is possible to get an idea not only about the existence of unevenness, but also about its direction. Let us explain what has been said in Fig. 110.
Rice. 110. Evaluation of the relief of the fundus by the dynamics of the width of the focal light strip (the illuminator is located centrally).
The picture that occurs when the doctor slightly shifts the slit lamp towards himself (I) and away from himself (II). 1 - a strip of focal light; 2 - strip of postfocal light; 3 - bands of prefocal light.
In Schemes A, the difference in the width of the light strip occurs abruptly (at the edges of a retinal tear with a flat retinal detachment). In Schemes B, changes in the width of the focal strip occur smoothly, in accordance with the gentle relief of the physiological excavation of the optic disc.
This technique is also used in the lateral position of the illuminator. Then, at the same time, complementary information about the relief is obtained both on the basis of taking into account the shape of the light strip and by estimating the unevenness of its width.
Finally, in some cases, when the retina sharply thickens without losing transparency, it becomes possible to analyze its deep structure also in a true optical section, with distinct differentiation of both anterior and posterior ribs(Fig. 111).
Rice. 111. Obtaining an optical section from the transparent membranes of the fundus in central serous retinopathy.
1 - front edge of the cut, repeating the relief of the surface of the retina; 2 - concave strip of the posterior edge of the cut in the zone of thickening of the transparent retina; 3 - the plane of the optical section with point inclusions in the thickness of the edematous retina; 4 - the border of the prominent area of the fundus.
The deterioration in the visibility of the posterior edge of the cut in some segment will most likely indicate a local decrease in the transparency of the retina in this place; relative expansion of the slice - an increase in the distance of the anterior surface of the retina from the pigment epithelium. It is not possible to single out its posterior surface in such a cut when using ShchL-56. Therefore, in each specific case, it is difficult to say what the cut was made with: whether it was only thickened retina, subretinal fluid, or both.
g) Use of indirect focal illumination. The focal light of the slit lamp is able to penetrate all layers of the wall of the eyeball. This can be verified by illuminating the outer part of the sclera and observing the pupil, which acquires a pink “diaphanoscopic” glow. If the light from the slit lamp is concentrated on the fundus in the form of a small rectangle, then it will be surrounded by a reddish halo. It - area of indirect luminescence of tissues. Analysis of the color shade of this glow, its brightness, and homogeneity allows you to determine the level that the detected pathological focus occupies, and to some extent its morphological essence (exudate, blood, pigment, areas of atrophy, depigmentation, etc.).
To clarify the interpretation of the results of the study using this method, we will refer to several simplified diagrams (Fig. 112).
Rice. 112. The nature of the indirect glow of the fundus and the scheme of its occurrence in various conditions of the internal membranes. Explanation in the text.
1. The border of the glow is narrow. This is a variant of the normal state (pigmented fundus).
2. The border of the glow is evenly expanded, bright. This is also a variant of the norm (weakly pigmented fundus).
3. The rim of the glow is expanded one way, asymmetrical. Most likely, this is caused by the presence of a substance under the choroid that conducts light well (liquid, exudate).
4. The opposite case- the light border with fuzzy boundaries is also asymmetric, but due to its local narrowing rather than expansion. You can think of soaking the choroid with blood.
5. The picture is similar to the previous one, but the shading border is clear. This is the result of an obstruction closer to the observer (dense exudate or blood under the retina).
6. The glow zone is expanded, light, with a yellow tint and clear boundaries. Under the retina is an additional light-conducting substance (liquid, fibrin).
7. The glow is non-uniform, additional luminous zones are visible. This is a sign of focal atrophy of the pigment epithelium and the choriocapillary layer.
8. The glow is also non-uniform, but not due to additional enlightenment, but due to the appearance of dark spots. There are clumps of pigment in the retina, which are visible diaphanoscopically.
9. The glow has a grayish yellow tint; a shadow mesh network is visible against its background. Cystic degeneration of the retina.
So, a uniform increase or decrease in the zone of indirect luminescence in different parts of the fundus most likely indicates variants of the norm. Local changes in the glow zone almost certainly indicate pathological processes in the inner membranes of the eye. Darkening is associated with the appearance between the shells or in their thickness of low-transparent inclusions (blood, pigment, scar, etc.). The enlightenment of this zone, on the contrary, may be due either to the fact that the additional substance conducts light well (moisture, liquid exudate, etc.), or to the atrophy of pigment-containing tissues.
The clearer the contour of local dimming or enlightenment looks, the closer the pathological focus is to the vitreous body. The appearance of additional glow zones is associated with focal depigmentation of the membranes, and the occurrence of local dimming of the luminous zone - with the introduction of pigment into the retina.
The methods discussed here are among the the most difficult in ophthalmoscopic diagnosis. They can be mastered only as a result of hard work with patients. We wish you success in this matter. In conclusion, a few words again about the mirror ophthalmoscope. This device allows you to get a significant part of the additional information that we have classified under the heading "clarifying". Of course, the lower magnification and methodological difficulties of reverse ophthalmoscopy make this task difficult. But work experience shows that it is possible to cope with it, especially after the basic techniques have been worked out on complex devices.
Let us consider some practical aspects of such a replacement of other instruments with a mirror ophthalmoscope. So, quite convincing data are obtained in the study of parallactic displacements of the details of the fundus picture. Shifts of the device in this case are replaced by wiggles of the ophthalmoscopic loupe in the right direction(including in any intermediate meridian, which is difficult to do on the BO). In the study, a magnifying glass of + 10.0D is used, taking it away from the eye of the subject to the full focal length.
Under these conditions, during reverse mirror ophthalmoscopy, it is often possible to observe various variants of shadow patterns in the fundus. Necessary mismatch between the illumination beam and the observation line is created by slight lateral displacements of the magnifying glass and illumination of the pupil not by the central, but by the peripheral part of the mirror. To assess the movement of shadows, it is enough to shake the mirror around the axis of the handle (as in skiascopy).
Obvious results are also analysis of retinal reflexes. When moving an ophthalmoscopic magnifying glass (but not a mirror!) the shifts of the reflexes on the retina coincide with those that take place when working on the BO. By choosing a lamp with a relatively straight filament and having mastered well the methods of projecting its image onto the fundus of the eye, it is possible to study the structure of pathological objects both in focal light and in indirect illumination. Even such subtle techniques as the analysis of deformations of the light strip on the fundus, the assessment of the width of its various sections, the degree of continuity, etc., are quite feasible with reverse ophthalmoscopy. It is only necessary to learn how to dose the focal light over the surface of the fundus, to ensure accurate fixation of the patient's gaze and, most importantly, stock up on the necessary patience and perseverance.
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6-10-2014, 18:42
This is clearly seen in Fig. 36, which schematically shows the fundus, a part of which, outlined by a circle, fell into the ophthalmoscopic field of view, in the indicated area of the fundus of the dishes, after branching, they go to the right, therefore, the papilla is located on the left. In other words, the top took into account, formed by the branching of the retinal vessels, as the arrow indicates the direction in which to look for the papilla of the optic nerve.
This method of searching for the papilla through the vessels can also be used with reverse ophthalmoscopy, you just need to remember that when examining this method, the patient must turn the eye not in the direction where the papilla is located, but in the opposite direction (against the anatomical arrow).
However, the location of the papilla can already be determined with simple ophthalmoscopic transillumination, namely: if from a distance of 40-60 cm a beam of light is directed into the eye with an ophthalmoscope, then, as you know, the reflex from the fundus will be the brightest when the light is reflected from the lighter papilla surface. If they sang, now, without losing this area of the fundus, proceed to ophthalmoscopic examination, then the papilla of the optic nerve will be in the ophthalmoscopic field of view.
The papilla appears as a yellowish-red or grayish-red circle, which is always lighter than the rest of the bottom of the eye and stands out especially in pigmented eyes. The shape of the papilla is either perfectly round or slightly oval. The inner edge of the papilla is usually less clearly defined than the outer. This is explained by the fact that in the inner part of the papilla there are more nerve fibers and blood vessels.
For the same reason, the inner half of the papilla is more red than the outer half, where the layer of neural subwindows is thinner and therefore the white reflex of the cribriform plate is more clearly visible. The papilla is quite often surrounded by a narrow yellowish-white strip, which adjoins in the form of a sickle to its outer part or encloses the papilla in a continuous ring.
This so-called scleral ring depends on the fact that the hole in the choroid through which the optic seal passes is larger than the hole in the sclera, which is visible in the form of a yellowish-white crescent or ring.
An accumulation of pigment is often observed near the outer border of the scleral ring, which is explained by stronger pigmentation of the edge of the hole in the choroid. The dark stripe bordering some part of the nipple is called the choroidal ring, its width in some cases can reach 14 PD (PD - papilla diameter).
The retinal vessels exit either from the center of the papilla or somewhat medially from the center. The further direction of the vessels and their division is described above in the anatomical outline. Distinguishing arteries from veins is quite easy: arteries are somewhat thinner than veins, have a lighter (orange-red) color and are less tortuous.
Veins always appear thicker as they are compressed (flattened) by vitreous pressure, are cherry red in color, and are more tortuous. Arteries differ from veins also in a characteristic reflex in the form of a light central strip, which is clearly visible on large vascular trunks. On the arteries, the ventral light strips have a light pink color, their width is about 14 vessel diameters.
In those places where the vessel makes a bend, so that it is no longer in a plane perpendicular to the observer's line of sight, the light penfalny strip either becomes poorly visible or disappears altogether. Light reflexes on the arteries depend on the reflection of light by the central part of the blood column moving in the vessels. On the veins there are light central stripes of white color, their width is much less than on the arteries, and is equal to from 110 to 112 - the diameter of the vessel.
It disappears at the slightest bend of the vein in the plane that is not perpendicular to the visual line of the observer. Light reflexes on large trunks of veins in the region of the papilla and in its immediate vicinity may often be absent. Vessel erasers are almost completely transparent, however, in some cases, there is a bypass of the arteries in the form of delicate, white light strips that accompany the vessel from one side and the other, parallel to the central light strip.
These additional light strips can be observed on large trunk: -: arteries only in the region of the papilla or near it.
In some eyes with a sharply pigmented fundus, the retina has Serov around the papilla for several PDs, it gives the impression of being awake; the posterior part of the fundus of the eye will be tightened with a light veil. On a detailed examination (in direct form), one can notice that the retina around the papilla is, as it were, striated with many radially arranged stripes, which depends on the presence of a developed supporting tissue in it, which is located mainly along the nerve fibers.
In eyes with a sharply pigmented fundus, wavy, shiny white stripes can be observed, which are located mainly along the vessels, but can also cross them. Sometimes they have the form of a wide variety of shapes: a sickle, an irregular opal, etc. Whatever shape these wavy stripes may have, they are nothing more than light reflexes of the retina.
This can be easily verified if, during the examination, by slight rotation of the ophthalmoscope, the illuminated area of the fundus is shifted in different directions; the observed bands change their shape, position, and some disappear altogether. Such an unusual picture of the fundus often confuses inexperienced researchers and they tend to explain the observed phenomenon by the presence of an inflammatory process in the retina, that is, they consider such an eye fundus not as normal, but as pathologically altered.
Light reflexes of the retina arise because the fundus of the eye does not actually have a strictly spherical surface, since the membrana limitans interna over the retinal vessels mimics forward somewhat and, as a result, concave cylindrical surfaces are formed between the vessels, which reflect the light of the ophthalmoscope in the form of bright reflexes. All these reflexes with an enlarged pupil are less noticeable or even disappear altogether.
The fundus illuminated by an ophthalmoscope, on which the papilla and retinal vessels are visible, can have not only a different color in different eyes, but also a peculiar pattern. In blondes, the fundus is light and has a light red color, in brunettes it is dark red, and in people with sharply pigmented skin (Negroes), the fundus is almost black (the color of a crow's wing).
The color of the fundus is determined by the choroid, which is translucent through the transparent retina, which has a red color. But, since the outermost layer of the retina is covered with pigment, then, depending on the amount of retinal pigment and its physiological color, the color of the fundus also changes. In cases where the outer layer of the retina is poorly pigmented and, as a result, the choroid is clearly visible, the fundus of the eye has not only a bright red color, but also a mottled pattern: it appears to consist of wide, loopy orange-red ribbons, with dark stripes and spots between them. .
These are visible choroidal vessels, which differ from retinal vessels primarily in that they look like wide, densely intertwined mites, which is explained by the presence of a large number of anastomoses in these vessels. The chorionic vessels pass under the retinal vessels, they do not have light reflexes, it is impossible to distinguish arteries from veins. When examining the fundus of the eye in the region of the equator, it is sometimes possible to see vorticose veins, to which the veins of the choroid approach from all sides, in the form of radially arranged ribbons (Table 30, Fig. 1).
Anyone who sees such an eye for the first time can easily take the detected changes in the fundus as pathological, but if you pay attention to the fact that dark spots are located on the fundus in a certain pattern corresponding to the distribution of the choroidal vessels, and also to the fact that as approaches to the equator become narrower and less convoluted, there can be no doubt that this fundus is normal (Table 5, Fig. 2).
A very important and most difficult part of the fundus of the eye to study is the area of the macula. In order to find the macula lutea during the examination in reverse, the patient is inserted to look at the hole in the ophthalmoscope, since when looking in the ophthalmoscopic field of view there will be an area of the fundus corresponding to one pole of the eyeball, where, as you know, the yellow spot.
It must be remembered that with this method of examination, the papilla of the optic nerve is outward from the macula (reverse image), approximately at a distance of -2 PD.
With direct ophthalmoscopy, it is most convenient to find the yellow spot, focusing on the outer part of the papilla. To do this, first of all, they look for the papilla of the optic nerve, take the outer edge of the papilla as the starting point, and with a slight rotation of the ophthalmoscope move the "Illuminated area outwards, where they look for the yellow spot.
If it does not give up, it is better to return again to the edge of the papilla and from there again go outward, since otherwise it is easy to deviate downward or upward from the actual location of the yellow spot. The main difficulty in examining the macula is that this area is most sensitive to light, and when the fundus is illuminated with an ophthalmoscope, a sharp pupil constriction occurs.
In this regard, it is sometimes advisable to use a flat mirror for ophthalmoscopy, which directs a smaller amount of light into the eye, and when using an electric ophthalmoscope, you should simply lower the degree of incandescence of the light bulb.
The yellow spot is ophthalmoscopically characterized primarily by the fact that small arterial branches are sent to it from all sides. This area, the size of the papilla, is located approximately 2 PD outward from the papilla of the optic nerve (Table 6, Fig. 1-e). When examined in reverse, it is surrounded by a bright light reflex, which has the form of a horizontally located oval (Table 6, Fig. 1-c). The vertical diameter of the oval is equal to the diameter of the papilla, the horizontal one is somewhat larger.
Its diameter is approximately equal to - 13-16 PD, but sometimes the spot is large and has an irregular triangular shape. The spot is especially clearly visible in the eyes with a weakly pigmented bottom, where it has a red color and somewhat resembles a hemorrhage. In direct examination, the macular reflex is usually absent, but if this method of examination also produces strong illumination of the fundus, which often happens when using an electric ophthalmoscope, then it is almost as well visible as in reverse examination.
The dark spot corresponding to the fovea centralis is more clearly visible when examined in direct form, and, in addition, when examined by this method, a light reflex, the so-called foveal reflex, is clearly captured in the center of the spot, which in some cases resembles a luminous dot, and in others has the shape of a sickle or ringlet (Table 6, Fig. 1-d). And ate and make light rotations with an ophthalmoscope, as is done with skiascopy, it can be seen that the fossa reflex somewhat changes its shape and position.
Macular and foveal reflexes, as well as other retinal reflexes, are less visible with a dilated pupil. The reason for reflexes in the area of the macula has the following explanation. The macular reflex occurs as a result of the reflection of light by the annular thickening of the retina around the macula.
The darker color and matte shade of the area surrounded by the macular reflex depends on the fact that the inner slope of the annular thickening of the retina around the macula refracts rays more strongly than the adjacent part of the fundus, and therefore less light enters from this area of the researcher.
The foveal reflex depends on the reflection of light by the strongly concave spherical surface of the fovea centralis and is nothing more than a reverse, reduced image of the light source that is in front of the pupil.
It is quite clear that this image is located in the vitreous in close proximity to the fovea centralis. When the fundus is illuminated with a mirror with a hole in the center, the reflex looks like a sickle or an annular shape, and when examined with an electric ophthalmoscope in focus, an image of a hot bulb filament is obtained and the reflex looks like a luminous point.
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