Yolk macular dystrophy

Introduction to yolk-like macular malnutrition This disease is also known as Best disease, pleomorphic macular degeneration. The disease is reported all over the world and is not uncommon. Usually seen in childhood, it features yolk-like lesions in the early macular area with obvious EOG changes, but normal vision, autosomal dominant inheritance. There is a clear family history, but there are also sporadic cases. In some cases, there is no typical change in fundus examination, and the electro-oculogram has changed significantly. The disease is characterized by irregular dominant inheritance. If patients are found, they should be treated separately. Children with retinal EOG examinations can have abnormal changes in 50% of their children. basic knowledge The proportion of illness: 0.004% Susceptible people: no special people Mode of infection: non-infectious Complications: retinal vein occlusion

Yolk-like macular malnutrition

(1) Causes of the disease

The cause is still unclear. The disease is autosomal dominant, with a clear family history, but there are also sporadic cases. In some cases, there is no typical change in fundus examination, and the electrooculogram has changed significantly. Irregular dominant inheritance, if a patient is found, and each child should have a retinal EOG test, 50% of the children may have abnormal changes.

(two) pathogenesis

Some people speculate that the disease occurred the day after tomorrow, because some patients did not find the lesion when they first examined the fundus, and found that the yolk-like degeneration changed after the follow-up, but these patients did not have an EOG test. Krill believes that this patient has a wide range from childhood or birth. The pigment epithelium is abnormal and secretes a special orange substance. After the cell ruptures, a cystic gap is formed. At this time, the visual acuity remains normal. Afterwards, the capsule can leak, some substances are absorbed, and the capsule is closed again. The anterior chamber is empy, and the capsule is pierced. The material toxin is stimulated, causing local atrophy, degeneration, and loss of vision in the corresponding part of the retina. Leakage can enter the pigment epithelium of the corresponding part, and the vascular permeability of the choroid is increased. Causes serous pigment epithelial detachment. Over time, there may be neovascularization, and blood vessels rupture and enter the subretinal.

Braley and Spirey believe that the Bruch membrane in the macular area is congenitally abnormal, and the membrane becomes thicker and produces yolk-like degeneration. At this time, the visual acuity is normal. After the membrane breaks into pieces, it is yolk-like rupture. In severe cases, edema, hemorrhage, and vision are caused. Sudden decline, if edema, bleeding absorption, vision can be temporarily restored, but repeated edema, bleeding leads to gliosis, pigment epithelial damage to form varying degrees of pigmented scars, and finally vision decreased permanently.

Yolk-like macular malnutrition prevention

Life restraint pays attention to rest, work and rest, life is orderly, and maintaining an optimistic, positive and upward attitude towards life is of great help in preventing diseases. Do the regularity of tea and rice, live daily, not overworked, open-minded, and develop good habits.

Yolk-like macular dystrophy complications Complications retinal vein occlusion

Deep rupture of the retina can occur in cystic rupture.

Yolk-like macular malnutrition symptoms common symptoms fundus changes edema green blind dehydration

The disease is caused by both eyes, bilateral symmetry, a small number of cases can be followed, the age of onset is mostly in young and young, but early vision is often unaffected, so most of them are found in routine fundus examination, even if the typical yolk is seen in the fundus Changes, visual impairment is also very slight, when the yolk is broken, and then atrophic lesions occur, the visual acuity is significantly reduced, the degree of visual impairment is not consistent between the two eyes, and it is difficult to estimate the visual status from the fundus performance alone. When the yolk is broken, the visual acuity is diminished, and then there is recovery. The visual field has more central dark spots in the later stage. The color vision may have mild red-green blindness, dark adaptation to normal, ERG normal, EOG abnormal, and the disease progression is divided into 4 stages. :

1. The initial macular spot in the early stage of yolk lesions may be normal. There is a yellow dot in the fovea at the time of onset. Similar to the hive-like structure, the visual acuity is not damaged, but the EOG often changes.

2. The macular area of the yolk lesion has a typical change. The center has a yolk-like orange-colored cystic bulge, and the shape of the round border is clear and uniform (Fig. 1, 2). It is semi-transparent and the retinal blood vessels cross over it. The lesion size is 0.5. ~3 disk diameter, its shape is very similar to the central egg yolk when fried eggs, surrounded by a circle of black rims, the lesion is very obvious and typical, but the patient's vision can be normal or only slightly decreased, visual function and degree of fundus change Very disproportionate, therefore, patients at this stage are less likely to seek medical treatment, so it is not easy to find this typical fundus lesion, and rare cases of multiple yolk-like lesions can appear in the fundus, the general process of the disease, the yolk phase appears in 3 ~ 15-year-old children and adolescents, this period of time is not long, about 4 to 5 years, sometimes yolk-like changes can completely disappear, the fundus almost returned to normal, but later there are new yolk-like lesions re-exit.

3. As the disease progresses, the yolk-like lesions disintegrate, showing the shape of the egg yolk being shattered (Fig. 3). Sometimes the substance in the lesion is dehydrated and coagulated, settled in the lower part of the capsule, and the upper part is liquid, and appears. The liquid level is called pseudo-accumulation, but in most cases, the yolk-like structure of the fracture stage is very irregular, the patient's visual acuity is significantly reduced, and the patient often sees the doctor. In some cases, the subretinal neovascularization in the lesion area may still appear. Causes bleeding and edema, making the lesion morphology more complicated.

4. At the end of the atrophic period, the pigmented epithelium and adjacent photoreceptor cells tend to shrink, forming scars, and the patient's vision is permanently damaged, leaving a thick central dark spot.

The macula is sometimes similar to yolk-like macular degeneration (pseudo-vitelliform macular degeneration) for other reasons, but EOG is mostly normal, more common in monocular, no genetic factors, and can be seen in the fundus There are other lesions that can be distinguished from the disease.

Yolk-like macular malnutrition

Genetic examination

2. Histopathology

Very rare, and most of the elderly patients with advanced disease, macular pigment epithelial layer, neuroepithelial layer and choroidal capillary layer are widely atrophied, the neuroepithelium and pigment epithelium of the lesion are replaced by the glial membrane, and the Bruch membrane is cleft and calcified. There is a wide accumulation of abnormal lipofuscin particles in the pigment epithelium. Regarding the nature of lipofuscin (the yolk-like component), it is considered to be a non-specific metabolite that can no longer be decomposed by lysosomes and incompletely degraded.

Fluorescein angiography: when the yolk is intact, it masks the choroidal background fluorescence, so it shows dark areas. Once the yolk is broken, it shows irregular fluoroscopy and obscuration. If there is neovascularization of the retina, dye osmosis occurs. Leakage phenomenon, fluorescing period is translucent fluorescence, which is mixed with speckle-like occlusion fluorescence, and in advanced cases with choroidal capillary occlusion, coarse choroidal vessels are seen in dim fluorescence.

Diagnosis and differentiation of yolk-like macular dystrophy

diagnosis

According to the disease, the macula has a yolk-like round or oval change, and the central vision is good. The typical fluorescein angiography and EOG abnormalities can be diagnosed.

Differential diagnosis

The disease should be identified with the following lesions:

1. Toxoplasmosis (toxoplasmosis) This disease can also often affect the macular area of the eyes. After the yolk-like breakage, the yellow matter flows into the retina and the patch is similar in size, but the toxoplasmosis is inflammation, in the vitreous and in front. Inflammatory cells are seen in the aqueous humor, and EOG is normal in the electrophysiological examination.

2. Pseudo-yellow yolk macular degeneration This disease generally has a small lesion, about 1/3 PD is large, EOG is normal, and there is capillary leakage around the fluorescein angiography center.

3. Age-related macular degeneration This disease may be accompanied by atrophic scars of subretinal neovascularization, and its fundus changes are difficult to distinguish from this disease, but the age of yolk-like degeneration is earlier than that of age-related macular degeneration.

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