Ocular Histoplasmosis

Abstract

The triad of ocular histoplasmosis syndrome (OHS), also known as presumed ocular histoplasmosis syndrome (POHS), is peripheral punched-out chorioretinal lesions, juxtapapillary atrophic pigmentary changes, and disciform macular change. This chapter reviews the epidemiology, clinical findings, evaluation, and treatment of the OHS. The OHS causes permanent loss of central vision in 2000 young adults per year. Although most cases are asymptomatic, macula can be involved with chorioretinal scars and/or choroidal neovascular membrane (CNVM) leading to legal blindness. Diagnostic evaluation tools include conventional or wide-angle fundus photography, fundus autofluorescence, fluorescein angiography, optical coherence tomography (OCT), and OCT-angiography. The treatment paradigm CNVMs associated with OHS has recently shifted significantly from thermal laser to photodynamic therapy (PDT), then to intravitreal antivascular endothelial growth factors (anti-VEGF) since the year 2000. Treatment with anti-VEGF can provide stabilization, often with improvement in vision with repeated injections.