Abstract
Abstract: :
Purpose:CD44 is an emerging novel marker of primary open–angle glaucoma (POAG). The aqueous humor concentration of the ectodomain fragment of CD44 (soluble CD44) is increased in POAG. Soluble CD44 is neurotoxic to retinal ganglion cells in vitro and its toxicity is blocked by hyaluronic acid. The purpose of this study was to determine if aqueous humor soluble CD44 concentration correlates with visual field loss in patients with POAG. Methods: Aqueous humor samples of POAG patients without diabetes were analyzed by CD44 enzyme–linked immunosorbent assay (ELISA) and the sCD44 concentration was compared with gender, race, age of onset, duration of disease, blood pressure, diabetes, glaucoma medications, cup/disc ratio, intraocular pressure (IOP), IOP amplitude, and visual field loss. Results:In white patients with visual field loss, a positive correlation was observed with aqueous humor soluble CD44 concentrations (ng/ml): 14.72 with mild, 15.17 with moderate, and 17.29 with severe visual field loss. In patients with hypertension, the sCD44 concentrations were higher, 18.5, compared with patients without hypertension.,15.1 (P<0.03). A bimodal correlation of soluble sCD44 was observed in African Americans:15.33 in mild, 18.96 in moderate, and 8.92 with severe visual field loss. The soluble CD44 concentration was significantly lower in African American patients than in white patients with severe visual field loss (P<0.001). Conclusions:Aqueous humor concentration of soluble CD44 correlates with POAG and all stages of visual field loss in white patients and with the mild and moderate visual field loss in African American patients. In African American patients with severe visual field loss, aqueous humor soluble CD44 concentration was less than in white patients as a result of either decreased cell release of soluble CD44 and/or end–stage POAG disease.
Keywords: visual fields • clinical (human) or epidemiologic studies: risk factor assessment • aqueous