Retinoschisis is a retinal disorder characterized by a cystic degeneration of the retina, leading to a split of retinal layers mainly at the level of the nerve fiber layer. Almost all patients have macular involvement, most commonly with foveal spoke-like streaks consisting of microcystic cavities that may coalesce over time. Retinal pigment epithelium atrophy and pigment clumping may occur. Peripheral schisis is evident in about 50% of patients with large bullous cavities that may resolve spontaneously leaving a pigmented demarcation line. Other retinal findings are white retinal flecks, exudative retinopathy with retinal detachment, perivascular sheathing and dendritiform vessels in the periphery. Vitreous veils are commonly seen that are caused by separation of the thin inner wall of a peripheral schisis cavity and inner wall holes. Bridging vessels may rupture into the cystic cavity or the vitreous. The onset of the disorder has been detected as early as three months, but the majority of cases are five years old or older. Many present with mildly decreased vision that cannot be corrected with glasses and the diagnosis is often delayed. Visual acuity is highly variable ranging from 20/20 to 20/200, but may decline with age and with complications such as vitreous hemorrhage and macular detachment. The disorder is also associated with axial hyperopia, posterior subcapsular cataract and strabismus. Fluorescein angiography shows minimal or no leakage as opposed to cystoid macular edema. Focal areas of vascular leakage into schisis cavity may be present as well as peripheral capillary nonperfusion. Electroretinograms exhibit a reduced b-wave and a preserved a-wave.
