The Impact of the Macular Photocoagulation Study Results on the Treatment of Exudative Age-Related Macular Degeneration

Abstract

Objective: To determine the percent of cases with all primary forms of exudative age-related macular degeneration that are eligible for treatment by the Macular Photocoagulation Study (MPS) guidelines in a retina clinic serving both as a primary care center and as a referral center. Design: Fluorescein angiograms of patients with age-related macular degeneration examined at the Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, during a 5-year period (1985 to 1990) were randomly selected and reviewed. Angiograms showing all forms of exudative age-related macular degeneration were eligible. The first 100 eligible angiograms identified constituted the study series and were classified into four groups: active choroidal neovascularization (CNV), pigment epithelium detachment, hemorrhage, and disciform scars. The active CNVs were further divided into three subgroups: classic (well defined), occult (poorly defined), and combined. Eligibility for laser treatment was determined exclusively with use of the published MPS recommendations for treatment of extrafoveal, juxtafoveal, and subfoveal membranes. Results: There were 10 cases in the pigment epithelium detachment group, 11 cases in the hemorrhagic group, and 16 cases with disciform scars. All of these 37 cases were ineligible for treatment by MPS guidelines. Sixty-three eyes had active membranes; 37 were classic CNVs (eight extrafoveal, seven juxtafoveal, and 22 subfoveal). All extrafoveal and juxtafoveal CNVs were found to be eligible for laser treatment. Eleven membranes of the subfoveal group were larger than 2 disc areas, a size for which the MPS did not demonstrate benefit from laser treatment. There were 19 membranes in the strictly occult CNV subgroup, all of them untreatable by MPS criteria. Seven cases had both occult and classic CNV, and all were larger than 3.5 disc areas and therefore ineligible for treatment. Overall, 26 cases were eligible for treatment by strict MPS criteria; these constitute 26% of the whole series and 41% of the active CNV cases in the series. Conclusions: Our results indicate that the MPS guidelines for laser treatment are applicable only to a minority of the cases with exudative age-related macular degeneration presenting to our clinic. Further studies should be conducted to identify additional treatment modalities for this common eye disease.