Factors related to spontaneous visual recovery in the ocular histoplasmosis syndrome

In an effort to better describe the phenomenon of spontaneous visual recovery in the ocular histoplasmosis syndrome (OHS), 700 patient records were reviewed. Spontaneous visual recovery was defined as a two or more line improvement in Snellen acuity after a minimum of 12 months of stable visual reduction to 20/70 or less, secondary to central disciform scarring. Ten cases of spontaneous visual recovery were found. Eight patients had recovery of vision only when visual acuity was reduced to 20/80 or less in the fellow eye. One patient experienced spontaneous recovery without visual loss in the fellow eye. Another patient experienced spontaneous visual recovery 57 months after xenon photocoagulation in the study eye. This group of patients was compared to 14 similar patients who did not experience spontaneous recovery when visual acuity was reduced to less than 20/80 in the fellow eye. Compared to the nonrecovery group, patients experiencing spontaneous visual recovery in OHS were younger at the time of visual loss in the fellow eye (30 years vs. 48 years, p<0.01); had a shorter interval of visual loss prior to visual loss in the fellow eye (44 months vs. 150 months, p<0.10); had smaller diameter scars (1,711 microns vs. 3,078 microns, p<0.05); and had shorter distances from the foveal center to adjacent normal retina (267 microns vs. 846 microns, p<0.01).