Schisis-Like Presentations of Familial Exudative Vitreoretinopathy Caused by FZD4 Mutations

Purpose: To describe a case series with schisis-like presentations of genetically confirmed familial exudative vitreoretinopathy (FEVR) caused by FZD4 mutations. Methods: Retrospective case review of 4 patients with FEVR caused by FZD4 mutations, analyzed by optical coherence tomography (OCT) for schisis-like characteristics. Results: Three pediatric patients and 1 adult patient presented with unilateral, inner schisis in the retinal periphery. Overall, the schisis was characterized by thickening of the inner retinal layers and column-like structures affecting mostly the internal limiting membrane, nerve fiber layer, and ganglion cell layer, while mostly sparing the inner nuclear layer. Conclusions: Patients with genetically confirmed FEVR caused by mutations in FZD4 can have a schisis-like presentation. This is a distinct entity from other retinal disorders that involve schisis. Since it can be hard to visualize clinically, peripheral OCT imaging should be performed during a retinal examination with the patient under anesthesia to fully evaluate these presenting characteristics.