Serpiginous choroiditis.

Serpiginous choroiditis is a rare, usually bilateral, chronic, progressive, recurrent inflammation of the choroid, retinal pigment epithelium, and choriocapillaris of unknown etiology. Based on clinical presentation, it can be classified into 1) peripapillary, 2) macular, and 3) ampiginous types. The clinical course, regardless of the presentation, is progressive with multiple recurrences leading to potentially significant visual loss. Visual outcome is directly related to the involvement of the para-fovea and fovea by the lesions or secondary choroidal neovascularization. The histological findings of the lesions are atrophy of the choriocapillaris, retinal pigment epithelium and photoreceptor cells, and moderate diffuse lymphocytic infiltrates throughout the choroid. Multiple etiologies including autoimmunity, infection, vasculopathy, and degeneration were proposed but none is well supported by clinical and laboratory evidence. Fluorescein and indocyanine green angiography have been useful in the assessment of the extent and the activity of lesions. Due to the insidious and progressive clinical course, an assessment of treatment outcomes needs long term follow-up. Currently, treatment with immunosuppressive and alkylating agents have shown possible efficacy in small case series. Larger clinical studies and interventional trials are required to further our understanding of the pathogenesis, etiology, and for the evaluation of treatment strategies.