A retrospective study was performed on 75 eyes with presumed ocular histoplasmosis syndrome and 59 eyes with aging macular degeneration to determine risk factors for visual loss in the early postoperative period after successful laser photocoagulation of primary and recurrent choroidal neovascular membranes (CNVMs). Despite successful obliteration of neovascularization, visual loss of two lines or greater occurred in 18.8% of eyes with presumed ocular histoplasmosis syndrome and 40.4% of eyes with aging macular degeneration (mean follow-up, 33.6 weeks). Factors which predicted visual loss after treatment included a short distance of CNVMs from the foveal center (P = 0.002), good preoperative visual acuity (P = 0.003), increased area of CNVM (P = 0.025), and postoperative internal limiting membrane wrinkling (P = 0.017). Eyes with CNVMs greater than 0.8 mm2 in area or less than 0.6 mm from the foveal center had at least twice the frequencies of visual loss of eyes without these characteristics.