Juvenile retinoschisis: causes, symptoms, diagnosis, treatment

X-linked juvenile retinoschisis is a sex-linked inherited vitreoretinal degeneration. Vision declines in the first decade of life. The disease is characterized by bilateral maculopathy combined with peripheral retinoschisis in 50% of patients. A defect in Müller cells causes a split in the nerve fiber layer and the rest of the sensory retina. Unlike congenital retinoschisis, acquired retinoschisis causes a split in the outer retinal layer. Males are affected. The inheritance type is X-linked, gene RS1. It manifests itself at the age of 5-10 years with complaints of reading difficulties due to maculopathy. Less often, the disease manifests itself in childhood with strabismus and nystagmus, accompanied by pronounced peripheral retinoschisis, often with hemophthalmos. The RS1 gene, responsible for the development of X-chromosomal retinoschisis, is localized on the short arm of chromosome 22.

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Symptoms of Juvenile Retinoschisis

Retinal detachment is the main clinical sign of juvenile retinoschisis. It occurs in the retinal nerve fiber layer. Retinoschisis is thought to result from dysfunction of the supporting Müller cells. Retinoschisis is accompanied by dystrophic changes in the retina, represented by golden-silver areas; white tree-like structures are formed by abnormal vessels with increased permeability of the walls. Giant retinal cysts surrounded by pigment often form at the periphery. This form of the disease, called bullous, is usually observed in young children and is associated with strabismus and nystagmus. Retinal cysts may spontaneously collapse. As retinoschisis progresses, glial proliferation, retinal neovascularization, multiple arcuate ruptures, hemophthalmos, or hemorrhages into the cyst cavity develop. Fibrous bands, avascular or vascular membranes and vacuoles are detected in the vitreous body. Due to the adhesion of the bands to the retina, tension (traction) occurs, which leads to the occurrence of tractional retinal tears and its detachment. Star-shaped folds or radial lines in the form of a star ("spokes in a wheel") are observed in the macular region. Visual acuity is significantly reduced.

• in foveal schisis, the smallest cystic spaces are arranged like "spokes in a wheel". A clearer picture appears in red-free light. Over time, the radial folds become less noticeable, leaving a blurred foveal reflex;
• Peripheral schisis is most often localized in the inferotemporal quadrant, does not spread, but can go through a series of secondary changes.
  • In the inner layer, consisting only of the internal limiting membrane and the nerve fiber layer, oval openings may occur.
  • In rare severe cases, the defects merge, and floating retinal vessels have the appearance of a “glassy veil”.
• Other symptoms include: perivasal cuffs, golden shine of the peripheral retina, retraction of the retinal vessels on the nasal side, retinal spots, subretinal exudate, and neovascularization.

"Spokes in a Wheel" - Maculopathy in Congenital Retinoschisis (Courtesy of P. Morse)

Complications: vitreous hemorrhage, retinal detachment cavities and retinal detachment.

Diagnosis of juvenile retinoschisis

The leading role in diagnosis is played by the ophthalmoscopic picture of the disease and ERG, which is sharply subnormal.

• Electroretinogram is unchanged in isolated maculopathy. In peripheral retinoschisis, there is a selective decrease in the amplitude of the b-wave Electroretinogram in comparison with the amplitude of the a-wave under scotopic and photopic conditions.
• The electrooculogram remains normal in isolated maculopathy and subnormal in severe peripheral changes.
• Color vision: impaired color perception in the blue part of the spectrum.
• FAG reveals maculopathy with small, “final” defects without leakage.
• Visual fields in peripheral retinoschisis with zones of absolute scotomas corresponding to the localization of schisis.

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Treatment of juvenile retinoschisis

Laser coagulation of the retina and surgical treatment. In case of retinal detachment, vitrectomy, intravitreal tamponade with perfluorocarbons or silicone oil, and extrascleral buckling are performed.

Forecast

The prognosis is unfavorable due to progressive maculopathy. Visual acuity decreases in the 1st-2nd decades of life and may stabilize until the 5th-6th decades with subsequent decrease. Patients with peripheral schisis may have a sharp decrease in vision due to hemorrhage or retinal detachment.

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