A prospective fluorescein angiographic study, comparing the incidence of cystoid macular edema in patients 67 years or older after intracapsular cataract extraction with a Binkhorst 4-loop implant, extracapsular cataract extraction with a Binkhorst 2-loop or 4-loop implant, and intracapsular cataract extraction with no implant (controls) was begun at the Bascom Palmer Eye Institute of the University of Miami School of Medicine on May 14, 1974. Excluded from these groups were all patients whom we did not consider to be suitable candidates for lens implant surgery. Fundus fluorescein angiograms were taken four, eight, and 16 to 24 months postoperatively. The surgery was performed by one group of surgeons and the angiograms were read by a group of retinal specialists. The intracapsular cataract extraction-implant and intracapsular-no implant groups had a comparable incidence of cystoid macular edema four, eight, and 16 to 24 months postoperatively. The extra capsular cataract extraction-implant and an intact posterior capsule group had a significantly lower incidence of cystoid macular edema than the intracapsular cataract extraction-implant group 16 to 24 months postoperatively. The differences were less significant at four and eight months. Visual function as measured by visual acuity was 6/12 (20/40) or better in approximately 80% of eyes with angiographic-proven cystoid macular edema.