Congenital X-linked Retinoschisis and Familial Exudative Vitreoretinopathy: Pathogenesis, Diagnosis, and Treatment

Congenital X-linked retinoschisis (CXLRS) is characterized by symmetric bilateral macular involvement, usually beginning in the first decade of life and affecting males. In the fundus examination, a wheel pattern developing due to schisis areas is observed in the macula. Fundus examination and optical coherence tomography (OCT) are essential for diagnosis in the early stages of the disease and exhibit characteristic findings. Peripheral retinoschisis occurs in approximately 50% of cases, usually in the inferior temporal quadrant. Visual acuity usually deteriorates in the first and second decades of life, but then remains relatively stable until the fifth or sixth decade. There is no proven treatment for CXLRS so far, gene therapy studies are ongoing. Familial exudative vitreoretinopathy (FEVR) is a rare inherited vitreoretinal disorder characterized by abnormal or incomplete vascularization of the peripheral retina. The disease is frequently inherited as autosomal dominant and less frequently autosomal recessive or X-linked recessive. FEVR is manifested by bilateral involvement, which may be asymmetrical. Its distinctive features include the avascular peripheral retina and peripheral ischemia, retinal neovascularization, and subretinal exudation. Epiretinal membrane and tractional retinal detachment may also develop in some patients. Laser photocoagulation therapy is effective in patients with peripheral retinal ischemia and neovascularization. In this review, the pathogenesis, clinical features, and treatment methods in CXLRS and FEVR disease will be discussed.