Concentric retinal pigment epithelium atrophy after a single photodynamic therapy.

Abstract

To report a case with concentric retinal pigment epithelium (RPE) atrophy after a single photodynamic therapy (PDT). We report a case of a 33-year-old female patient who developed RPE atrophy after a single standard PDT for treatment of a juxtafoveal, predominantly classic choroidal neovascularization (CNV). After a single PDT treatment, visual acuity increased from 20/50 to 20/20. Six weeks after PDT, a concentric area of RPE atrophy was clearly visible on fluorescein angiogram. This circular area corresponded to the 3500 microm diameter of the laser spot used in the PDT treatment. The visual acuity and the RPE atrophy remained stable over the follow-up period of 3 years. We are unable to explain the exact mechanism of the observed RPE changes; however, they did not lead to loss of visual acuity. Different reasons for the RPE atrophy such as collateral damage of the choriocapillaris with a subsequent secondary RPE atrophy, a direct photochemical effect due to the early localization of the photosensitizer in the RPE, or a depigmentation or photobleaching of the RPE, which led to a window defect in the fluorescein angiogram without loss of the major functional properties of the RPE, are possible mechanisms involved in the development of the documented lesion.