Presumed Ocular Histoplasmosis Syndrome

Abstract

Presumed ocular histoplasmosis syndrome (POHS), also known as ocular histoplasmosis syndrome, is a multifocal disorder of the choroid and retina that is thought to be caused by Histoplasma capsulatum. H. capsulatum is a fungal pathogen that is endemic to the Ohio and Mississippi River Valleys. The classic clinical signs of POHS include atrophic chorioretinal scars, peripapillary chorioretinal atrophy, and choroidal neovascularization (CNV) in the absence of vitreous inflammation (Fig. 7.1). The characteristic findings of POHS may be detected in completely asymptomatic individuals; however, the development of CNV can result in a variety of symptoms, including metamorphopsia, paracentral scotomas, and vision loss. Numerous treatment modalities have been employed for POHS, including laser photocoagulation, vitreoretinal surgery, photodynamic therapy (PDT), corticosteroid therapy, and anti-vascular endothelial growth factor (VEGF) therapy, now the dominant treatment in current practice patterns.