Choroidal atrophy in degenerative myopia

Introduction to choroidal atrophy in degenerative myopia Degenerative myopia (also known as pathologic myopia) is different from general myopic refractive error. In addition to high myopia, the affected eye is accompanied by degenerative changes of the fundus and visual impairment. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific people Mode of infection: non-infectious Complications: cataract Glaucoma

Causes of choroidal atrophy in degenerative myopia

(1) Causes of the disease

It is currently confirmed that myopia is the result of a combination of genetics and environment, and heredity plays a very important role in degenerative myopia.

(two) pathogenesis

The vast majority of degenerative myopia is a congenital disorder. Guggenheim et al. performed a statistical analysis of the prevalence of degenerative myopia and the genetic status between the parents and the offspring. The results were significantly higher than the low myopia, indicating the hereditary pathogenesis of degenerative myopia. It plays a very important role. The genetic method of degenerative myopia is extremely complicated. It is reported to have autosomal dominant inheritance, autosomal recessive inheritance, sexual chain inheritance and other genetic methods. In addition, Balacca believes that the pathogenesis of degenerative myopia should include Various factors affecting scleral collagen, some long-term visual disorders can affect the pituitary system and change the hormone balance. This hormone balance is related to the continuous weakening of scleral collagen, which is prone to myopia. The microcirculation disorder of the fundus can cause scleral collagen. Fiber destruction, which leads to the extension of the sclera, degeneration of myopia, in addition to heredity, acquired environment such as general health, living environment, personal habits, long-term use of close eye work, etc., can contribute to the deepening of myopia.

Prevention of choroidal atrophy in degenerative myopia

Prevention: Patients with high myopia need regular observation and should pay attention to eye hygiene.

Complications of choroidal atrophy in degenerative myopia Complications cataract glaucoma

Vitreous lesions, complicated cataracts, glaucoma, etc. are very common complications.

Symptoms of choroidal atrophy in degenerative myopia Common symptoms Visual deformity Intraocular pressure increased pigmented microcirculation disorder Visual impairment Dark spot

The main symptoms are vision loss, poor corrected vision, and visual distortion and flying mosquitoes. The patients with degenerative myopia have larger eyeballs and the cornea is more convex than normal. Therefore, the anterior chamber is deep, the pupil is larger than the emmetropia, and the response to light is slow. Vitreous degeneration liquefaction, degenerative myopia mainly showed diffuse and limited atrophy lesions, the posterior pole is the most obvious, according to the axial axis, visual function, color vision, dark adaptation and fluorescent angiography, the fundus lesions are divided into diffuse, Plaque and composite lesions type 3, diffuse retinal choroidal atrophy lesions corrected visual acuity, plaque lesions, corrected visual acuity were below 0.5, complex and plaque similar.

1. There are two main types of diffuse lesions.

(1) diffuse atrophy of the choroid: the choroidal matrix pigment is reduced, the color of the fundus is lighter, the pigment is less, the choroidal blood vessels are clearly visible, and the tigroid fundus is the fundus, the gap of the choroidal blood vessels is larger, and the number of blood vessels is smaller. This atrophic change is evident in the posterior pole of the eyeball, especially in the macula, with a near-arc arc on the temporal side of the optic disc, and the arc width generally does not exceed one optic disc diameter (PD).

(2) lacquer crack: It is a common change in the posterior pole of the myopic fundus. In the macula or posterior pole, yellow-white or white stripes are visible, which are net or branched, resembling a crack on the lacquer. Therefore, the boundary is unclear, jagged, and the number is different. It can be perpendicular or parallel to the choroidal blood vessels. The paint crack is caused by the rupture of Bruch membrane and RPE atrophy, and some are connected with arc-shaped plaque, which is closely related to chorioretinal atrophy. Fluorescein angiography can be seen in the early stage of fluorescein fluorescing. Sometimes the choroidal vessels are crossed underneath. The arteriovenous phase is enhanced by fluorescence. In the late stage, the tissue at the crack of the paint is colored, and there is strong fluorescence, but there is no leakage. It is called pseudo- fundus vascular-like streak or crack-like Bruch membrane fissure. Through fluorescence angiography and three-sided mirror observation, the lacquer cracks are small, irregular, sometimes intermittently pale yellow lines or grainy, sometimes Branched, located in the deepest part of the retina, often with large or medium choroidal vessels across the bottom, seen in and around the macula, some may be accompanied by choroidal hemorrhage, Klein according to the number of cracks And divide it into 2 grades: 1 to 2 are grade I, 3 or mesh are grade II, according to the crack site divided into 3 types: macular type, optic disc temporal type and discoid complex type, follow-up lesions Enlargement, increased number, accompanied by neovascularization under the retina, large scars around the scar, and some recurrent bleeding.

The lacquer crack pattern may be caused by Bruch membrane rupture and pigment epithelial atrophy. The mechanism may be related to genetic factors, and may be related to biomechanical abnormalities such as axial lengthening, intraocular pressure elevation, intraocular layer deformation and Bruch membrane traction tearing. Related factors such as cracking, and related to blood circulation disorder, age, caused by damage of pigment epithelial layer-Bruch membrane capillary layer, lacquer cracks rarely directly impair function, but can cause visual deformation and relative side center Dark spots, when the lacquer cracks rupture, there may be new blood vessels under the retina, causing macular hemorrhage, forming Fuchs plaque, which is a precursor to further damage of vision. The lacquer crack finally induces the choroid, further atrophy and degeneration of the retina, and Avila paint cracks. The actual incidence may be higher because some may have been fused with the deep choroidal atrophy.

2. Some special atrophic lesions in the diffuse atrophy of localized lesions constitute a limited lesion, which has the following types:

(1) Conus and the circum papillary choroioretinal atrophy around the optic disc: Elschnig first pointed out that the arcuate plaques are congenital, protruding posterior to the posterior pole of the degenerative myopia, causing the temporal side to retreat and change The direction of the scleral choroidal tube and the optic nerve trunk contained therein becomes oblique, and a near vision arc is formed on the temporal side of the optic disc. The myopic arc can be annular, surrounding the optic disc, and the arc is mostly yellowish white with a little pigment (Fig. 2A). The myopia arc is slightly brown to the side of the disc, and the boundary is blurred. It is a supertraction conus with a ridge-shaped bulge. The myopic arc is called the inversive conus on the nasal side of the optic disc, and is called the Fuchs arc on the lower side. (Fuehsconus), sometimes there are double re-arc arcs on the temporal side of the optic disc, which are white and reddish-brown, respectively. The former is due to direct exposure of the optic nerve obliquely into the sclera, or the posterior pole protrudes posteriorly to form posterior staphyloma, the retinal pigment epithelium and The choroid and the entrance of the optic nerve sclera are separated from the normal connection position. The larger the arc spot on the temporal side of the optic disc, the tongue may extend toward the macular area, sometimes with the macula. The yellow-white atrophy is connected, and the atrophic area also shows strip-like pigmentation. The hardened choroidal vessels are often seen, and the retinal vessels are normal.

(2) posterior scleral staphyloma: When the posterior part of the degenerative myopic eye grows significantly, the posterior pole can produce limited scleral swelling, and the edge can be sloped or steep. During ophthalmoscopy, These areas are yellow-white, round or irregular, confined or diffuse, isolated or in pieces, with a large number of pigments in these areas, which, with the development of atrophy, were previously considered to be choroidal sclerosis in yellow or white The choroidal vessels appear in the atrophic area like the vascular sheath, and their white appearance is altered by the covered REP cells. The myopic ocular swelling is accompanied by atrophy of the REP layer and the choroidal vascular layer. The atrophic area can be clinically defined. In the degenerative myopia, 75% have posterior scleral staphyloma. After the ophthalmoscope, the scleral staphyloma begins to show a dark or dark brown half-moon line on the edge of the lens. The retinal blood vessels bend on the line, and sometimes the edge of the posterior sclera is round. Shaped sputum, retinal blood vessels bulge on it, posterior scleral staphyloma is common on the temporal side of the optic disc, and can also include the optic disc and the macula to form a circular dark line, such as indirect eyes Examination can be observed after the purchase of the full view of the grape swollen, three-dimensional display of the size, location and center of the depression, posterior scleral grape swollen into 3 types: macular, optic disc surrounding and disc-plaque, posterior scleral staphyloma and paint Related to crack patterns.

(3) Macular hemorrhage and Fuchs plaque: There are often dark spots in the degenerative myopic macula, originally described by Foster, which is the choroidal hemorrhage in the macular area. The choroidal atrophy is severe, and the posterior pole has a wide range of yellow-white spots and circles. Or elliptical pigmentation spots, the latter is Fuchs plaque, 1/3 to 3/4PD in size, slightly bulging, often brown or brown in the center, located between the macula of the optic disc or the macular area, which can occur near this black spot Other changes in hemorrhagic and degenerative myopia, the Fuchs plaque sometimes enlarges and becomes irregular, and Gass believes that the Fuchs plaque is caused by the rupture of the Bruch membrane and the macular degeneration of the subretinal neovascularization, which occurs under the retina under the macular area. Conditions of neovascularization cause discoid detachment of the macula, and finally changes in scarring and pigmentation develop so-called Fuchs plaques.

(4) Subretinal neovascularization in the macula: Fundus hemodynamic studies have shown that the microcirculation of degenerative myopia has obvious obstacles. In the normal macular area, the retinal capillaries are arranged in an annular shape with a 0.5 mm diameter capillaries. Area, degenerative myopia due to microcirculation of the fundus, choroidal capillaries and RPE atrophy, so that the macular area of the capillary ring is different degrees of defects, prone to subretinal neovascularization.

(5) cystoid degeneration of the macula and macular hole: under the ophthalmoscope, the macula can be seen with a clear circular erythema with a diameter of 1/3 to 1/2 PD. The retina adjacent to the erythema is slightly grayish. If accompanied by localized detachment, There is a reflective circle around it. The slit lamp is observed under the microscope. If it is cystic degeneration, the light cut surface has a thin anterior capsule wall tangential line; if it is a slit, the line is interrupted, and the tangential line of the outer wall of the split hole is misaligned with the surrounding retinal surface tangent line.

(6) Peripheral retinal choroidal degeneration: The peripheral lesions of myopia are divided into:

1 diffuse choroidal degenerative lesions;

2 banded choroidal degenerative lesions;

3 retinal cystic degeneration.

The manifestations of peripheral degeneration are:

1 pigment degeneration: increased pigmentation in spots or spots, may be related to vitreous traction, abnormal biochemical stimulation caused by pigment epithelial cell proliferation, the long axis of the eye is obvious, more common in <40 years old;

2 Paving stone-like degeneration: a choroidal retinal atrophy with a small white or elliptical border, which may be accompanied by massive pigmentation spots, and the choroidal vessels in the lesion are clearly visible;

3 lattice-like degeneration; 4 no pressure to whiten;

5 cystic degeneration and cystic degeneration, most of the lesions have a shallow serous detachment, angiography is strong fluorescent state, sometimes accompanied by leakage, scars left after the healing of the lesion, long-term pigmentation can increase.

Examination of choroidal atrophy in degenerative myopia

1. Genetic examination.

2. Histopathological degeneration myopia increases, the lesions are mainly in the equator, especially the posterior pole, the sclera is thin, scleral staphyloma is formed in the posterior pole, the choroid is thin, the matrix pigment is lost, the number of blood vessels is reduced, small blood vessels and capillaries The blood vessels disappeared, the Bruch membrane became thinner, and rupture occurred. The ciliary body was significantly atrophied, mainly due to the hypoplasia of the annular muscle fibers, the chorioretinal atrophy, the RPE of the atrophy area disappeared completely, and the RPE significantly proliferated to form Fuchs, which was covered with a layer of glue. Acellular exudate.

3. Fundus fluorescein angiography When the diffuse lesion is mild, the posterior pole of the arterial phase is a bit or linear, showing a paint crack. The brightness is enhanced with time, but it does not enlarge. After the background fluorescence disappears, it lasts for a long time. It does not disappear, and there is atrophic plaque in the extreme part of the lesion. The angiography shows that the arterial phase has a wide range of punctate, linear or flaky fluorescent spots or strong fluorescent areas and weak fluorescent areas, indicating that the choroidal capillary layer is atrophied, showing coarse Choroidal vascular filling.

4. Indocyanine green angiography degenerative myopia patients due to the extension of the axial length, scleral bulging and the formation of posterior scleral staphyloma, not only can lead to some complications, but also related to the choroidal circulation has also changed, fluorescent angiography In addition to some choroidal vascular structures seen in the area of the atrophic foci, choroidal vessels in other sites are not visible due to normal RPE, and indocyanine green angiography can clearly observe the choroidal vascular structure, compared with normal eyes. Indocyanine green angiography showed that the degenerative myopia was significantly deficient in choroidal vessels or choroidal vessels. It can clearly show the peritrophy around the optic disc and the macular area of the degenerative myopia. The indocyanine green angiography is visible in the macular area. Invasion of the posterior ciliary artery and subsequent choroidal capillaries, the choroidal vessels in the atrophy area are island-like without perfusion or poor perfusion, so the indocyanine green angiography shows a lack of choroidal capillaries in the late stage. There are still choroidal capillaries around Fluorescence, in fluorescein angiography and indocyanine green angiography, the choroidal large vessels in the weakly fluorescent atrophy area are filled early, and in the fluorescein angiography, the atrophic area is gradually colored, and in the indocyanine green angiography, they remain weakly fluorescent, The boundary of the atrophy zone is clear, there is no leakage and coloration, and the pigmentation zone appears to mask the fluorescence.

The lacquer-like pattern is weakly fluorescent in the late stage of indocyanine green angiography, which represents the choroidal capillary atrophy at the crack, while the fluorescein angiography may not show some choroidal capillary atrophy under the lacquer-like pattern, which is shown in the FFA. The lacquer-like pattern is strongly fluorescent, while the indocyanine green angiography is weakly fluorescent. The reason may be that the reduction and shrinkage of the choroidal capillaries reduces the amount of indocyanine green molecules passing through the lacquer-like pattern, while the lacquer-like crack and its choroid Capillary changes in turn lead to a decrease in choroidal perfusion.

Diagnosis and diagnosis of choroidal atrophy in degenerative myopia

The optometry determines the refractive properties and diopter. According to the clinical manifestations and the development rules, it is not difficult to make a diagnosis in combination with the necessary auxiliary examination.

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