Objective: To evaluate experimentally the conditions necessary for the formation of serous detachments.
Methods: Selective injury to the retinal pigment epithelium (RPE) and choriocapillaris was produced in cats using weak laser burns and intense diffuse light, with or without photosensitization with rose bengal. The fundi were analyzed by observation, fluorescein angiography, and histologic examination.
Results: Injuring the RPE alone did not cause detachments. Focal injury to the RPE and choriocapillaris caused moderate detachment only when an area surrounding the focal leakage site had been subjected to light damage. Diffuse injury to the RPE and choriocapillaris caused broader detachments.
Conclusions: Three conditions are necessary for serous detachments to form: (1) a source of fluid pressure, (2) a defect in the blood-retinal barrier (entry site), and (3) an area of impaired fluid transport beyond the site of leakage (if fluid is to accumulate over a broader area).