Since the number of cases for each of the conditions in our study was small, only preliminary conclusions can be made; in order to establish the fluorescein pattern of each of these peripheral retinal lesions, additional studies will be required. The following summarizes our preliminary observations. 1. Areas of retinal white-with-pressure or without and peripheral retinal cystoid degeneration did not reveal remarkable fluorescein angiographic findings. One exception was in an area of pigment epithelial disturbance characterized by atrophy and proliferation, which showed a "window and masking" effect of choroidal fluorescence. 2. Fluorescein angiography of areas of the fundus with lattice retinal degeneration showed little or no findings in early or mild cases. In severe or advanced cases, the affected retina revealed poor or absent perfusion caused by vascular occlusion. The retinal and choroidal circulation was devoid of fluorescein leakage. Advanced lesions displayed choroidal hypofluorescence in areas of pigment proliferation and hyperfluorescence in areas of pigment atrophy. 3. In advanced cases, occlusive vascular changes over areas of acquired retinoschisis were observed. There was intraretinal leakage of the dye from deep capillaries and pooling of the dye in cystic cavities near the margin of the retinoschisis. 4. There was no perfusion of the choroid and retina in the area of the hole and in the retina surrounding it. This finding suggests choroidal and retinal ischemia in the pathogenesis of a retinal hole. 5. Fluorescein angiography of retinal tears revealed fluorescein leakage along the edge of the tear and absent perfusion of the retinal flap. The retinal and choroidal circulation-around the tear was otherwise unremarkable. The choroidal fluorescein underlying the retinal flap was not visible, perhaps because it was masked by the retinal flap. 6. Our fluorescein angiographic findings in cases of rhegmatogenous retinal detachment confirmed those of others [7, 8, 10]. Transit of fluorescein through the retinal circulation was sluggish. The retinal capillaries were dilated. 7. In cases of rhegmatogenous retinal detachment which had become reattached surgically, areas treated with diathermy or cryoapplications showed absent or diminished choroidal and retinal perfusion. Leakage of the fluorescein from capillaries in the optic disc and retina in the posterior pole was sometimes persistent several months postoperatively.