EXPRESSION OF CYCLOOXYGENASE-2 IN CHOROIDAL NEOVASCULAR MEMBRANES FROM AGE-RELATED MACULAR DEGENERATION PATIENTS

Abstract

Purpose: 

The objective of this study was to investigate the expression of cyclooxygenase (COX)-2 in human choroidal neovascular membranes.

Methods: 

Paraffin-embedded sections of choroidal neovascular membranes excised from 16 patients with wet age-related macular degeneration were used for this study. Sections were subjected to immunohistochemistry using a monoclonal mouse antihuman COX-2 antibody. Staining was classified as either negative or positive in retinal pigment epithelial cells, vascular endothelial cells, and fibroblasts. Serial sections were stained for vimentin expression to confirm tissue antigenicity.

Results: 

Eleven of 16 (69%) choroidal neovascular membranes stained positive for COX-2 in retinal pigment epithelial cells, with 6 (38%) of these also expressing COX-2 in vascular endothelial cells and 6 (38%) in fibroblasts. None of the sections that were negative for COX-2 in the retinal pigment epithelial cells showed COX-2 expression in the other cell types assessed. There was a statistically significant difference (P = 0.0097) in the mean ages between the COX-2 positive group (65.6 years) and COX-2 negative group (76.8 years) as determined by a two-tailed, unpaired Student’s t-test.

Conclusion: 

The expression of COX-2 in human choroidal neovascular membranes suggests a possible role for this modulator in age-related macular degeneration pathogenesis. The age-dependent expression observed is novel and warrants further investigation.

In Brief

The expression of COX-2 was investigated in human choroidal neovascular membranes secondary to age-related macular degeneration. Immunohistochemical results demonstrate that a subset of membranes assayed exhibit COX-2 positivity. Expression of COX-2 seems to occur in an age-dependent manner, with membranes from older patients generally lacking this expression.