BASE-LINE AND EARLY NATURAL-HISTORY REPORT - THE CENTRAL VEIN OCCLUSION STUDY

Objectives: To evaluate panretinal photocoagulation for ischemic centr al vein occlusion and macular grid-pattern photocoagulation for macula r edema with reduced visual acuity due to central vein occlusion and t o further define the natural history of central vein occlusion. Design : A multicenter randomized controlled clinical trial supported by the National Eye Institute, Bethesda, Md. Patients: A total of 728 eyes fr om 725 patients were entered into one or more of four study groups: pe rfused, nonperfused, indeterminate perfusion, and macular edema. Resul ts: Follow-up of study patients is still in progress and no results ar e available for the randomized groups (nonperfused and macular edema). Thirty-eight (83%) of 46 evaluable eyes in the indeterminate group ev entually demonstrated at least 10 disc areas of nonperfusion (28 eyes) or developed iris and/or angle neovascularization before retinal stat us could be determined (10 eyes). Four-month follow-up information is available for 522 of the 547 eyes in the perfused group. Thirty of the se 522 eyes demonstrated iris and/or angle neovascularization at or be fore the 4-month follow-up visit. An additional 51 eyes had developed evidence of at least 10 disc areas of nonperfusion by the time of the 4-month visit. Conclusions: These findings confirm the importance of f requent follow-up examinations, including undilated slit-lamp examinat ion of the iris, and gonioscopy in the management of all patients with recent onset of central vein occlusion.