Spontaneous Recovery Phenomenon In The Presumed Ocular Histoplasmosis Syndrome

Abstract

The presumed ocular histoplasmosis syndrome (POHS) is an important cause of legal blindness in the eastern half of the United States. It is characterized by a prolonged clinical course during which the lesion may show continued activity both ophthalmoscopically and angiographically for 1 1/2 to 2 years. The prognosis for these patients has remained poor, despite the many treatment modalities. In a small percentage of patients (9% or 13 patients), we have seen a remarkable return of vision (to 20/100 or better) in an eye with a long-standing macular scar secondary to histoplasmic choroiditis. Perhaps as many as 9 to 10% of patients can recover useful macular function that previously was lost. In fact, 1 patient in this series experienced a return of 20/20 vision in an eye that had deteriorated to 20/400. Six hundred seventy-five cases of POHS were reviewed. Of these, 144 contained complete follow-up information documented by visual acuity evaluations, fundus photography, and fluorescein angiography. Of the 144 patients originally studied, 13 were identified as having undergone a spontaneous recovery, defined as improvement in visual acuity of at least three lines on the Snellen chart from the patient’s worst visual acuity after the lesion had become inactive. Patient histories, ophthalmoscopy, fluorescein angiography, and fundus photography of all 13 patients were examined and compared to identify any clinical or demographic characteristics common to patients exhibiting the spontaneous recovery phenomenon.