Stargardt's disease

Stargardt's disease (yellow-spotted fundus, yellow-spotted dystrophy) is the macular degeneration of the retina, which begins in the pigment epithelium and manifests itself as a bilateral decrease in visual acuity at the age of 10-20 years.

Stargardt's disease was described by K. Stargardt as early as the beginning of the 20th century. As a hereditary disease of the macular region with polymorphic ophthalmoscopic picture: "broken bronze", "bull's eye", atrophy of the choroid, etc.

By position cloning, the main locus of the gene for Stargardt's disease expressed in photoreceptors, which was called ABCR, was determined. In the autosomal dominant type of inheritance of Stargardt disease, localization of mutated genes in chromosomes 13q and 6ql4 was established.

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Symptoms and Diagnosis of Stargardt's Disease

The results of genetic studies conducted in recent years show that, despite the differences in the clinical picture, retinitis pigmentosa, Stargardt's disease, yellow-spotted fundus and age-related macular degeneration are allelic abnormalities of the ABCR locus.

The phenomenon of "bull's eye" is ophthalmoscopically visible as a dark center surrounded by a wide ring of hypopigmentation, followed by a hyperpigmentation ring. On the PHAG with a typical phenomenon of a "bullish eye" on a normal background, zones of absence of fluorescence or hypofluorescence with visible choriocapillaries are revealed. Histologically, there is an increase in the amount of pigment in the central zone of the fundus, atrophy of the adjacent pigment epithelium of the retina, and a combination of atrophy and hypertrophy of the pigment epithelium. The absence of fluorescence in the macular area is due to the accumulation in the pigment epithelium of the retina lipofuscin, which is a screen for fluorescein. Lipofuscin, in addition, weakens the oxidative function of lysosomes and increases the pH of retinal pigment epithelium cells, which leads to a loss of their membrane integrity.

There is a rare form of yellow-spotted dystrophy without changes in the macular area. In this case, between the macula and the equator, multiple yellowish spots of various shapes are seen: rounded, oval, elongated, which can merge or settle separately from each other. Over time, the color, shape and size of these spots can vary; the picture on PHAG also changes: the areas with hyperfluorescence become hypofluorescent, which corresponds to the atrophy of retinal pigment epithelium.

In all patients with Stargardt's disease, relative or absolute central scotomas of different sizes are identified depending on the distribution of the process. With yellow-spotted dystrophy, the field of vision can be normal in the absence of changes in the macular area.

In most patients there is a change in color vision according to the type of deuteronopia, red-green dyschromasia or more pronounced. With yellow-spotted dystrophy, color vision can be normal.

Spatial contrast sensitivity in Stargardt's dystrophy has been significantly changed in the entire frequency range with a significant decrease in the mean and its complete absence in the region of high spatial frequencies - the "cone-shaped dystrophy" pattern. Contrast sensitivity is absent in the central region of the retina within 6-10 °.

In the initial stages of Stargardt's dystrophy and yellow-spotted dystrophy, ERG and EEG remain within normal limits, in the advanced stages the cone components of the ERG decrease and the EOG parameters become subnormal. Local ERG - subnormal already in the early stages of the disease and becomes unregistered as the disease progresses.

Differential diagnosis of Stargardt's disease should be carried out with dominant progressive foveal dystrophy, cone, cone-rod and rod-cone dystrophy, juvenile retinosis, vitelliform macular dystrophy, acquired drug dystrophies (eg, with chloroquine retinopathy), with severe toxemia of pregnancy.

Treatment of Stargardt's disease

There is no pathogenetically grounded treatment. It is recommended to wear sunglasses to prevent the damaging effect of light.