Presumed histoplasmic maculopathy: xenon photocoagulation.

Every investigation into the efficacy and role of photocoagulation in the management of PHM has been handicapped by the lack of a valid control series. In all first eyes, the results of photocoagulation are better than in second eyes. The increased salvage rate of central visual acuityof 20/50 or better in first eyes without photocoagulation is on the order of 15.8 percent to 28.6 percent-versus 25 to 38 percent in first eyes with photocoagulation (an average of 54 percent salvage rate for all first eyes). However, in second eyes, even though the number of eyes is small, it appears that nonphotocoagulated eyes do better than those that have been photocoagulated: 46 percent of nonphotocoagulated second eyes versus 33 percent of second eyes with photocoagulation retain central vision of 20/50 or better. Comparison of our results with some of the other published studies indicates some disparity in results [1-5], arising, most plausibly, from variations in the severity of the maculopathy just prior to photocoagulation. It is our contention that carefully designed prospective studies are needed, in which cases would be randomized for treatment in groups classified according to severity of the process (for example, size of SNV, proximity of SNV to fovea, and amount and location of subretinal hemorrhage). In order to obtain sufficient cases for analysis, a collaborative study may be essential in which the results and analysis of the cases are compiled by an independent party not involved in the treatment of evaluation of the patients. Despite this lack of clinical corroboration, it is my firm belief based on clinical experience that photocoagulation does have a role in the management of this vision-threatning process.