Cyclooxygenases (COXs) are involved in choroidal neovascularization (CNV). However, the relative contribution of COX-1 and -2 to CNV has not been determined. In this study, the expression of COX-2 was investigated in CNVs in a murine laser-induced model. Subsequently, we found that experimental CNV expressed COX-2, most remarkably around the highly vascularized lesions. To examine the effect of COX-2 inhibition on CNV, etodolac, a non-steroidal anti-inflammatory drug with a high COX-2 selectivity, was tested on murine CNV model. The results demonstrated that the intensity of fluorescein leakage from the photocoagulated lesions decreased significantly compared to the control eyes following etodolac administration. The area of CNV lesions, as examined using histological sections and choroidal flatmounts at day 7, demonstrated that the average size of the CNV lesions was significantly reduced in the etodolac-treated eyes compared to the control eyes. Together, our results demonstrated that selective COX-2 inhibition suppresses CNV. (C) 2004 Elsevier Inc. All rights reserved.