Perfusion Pressure Correlates With Visual Acuity in Patients With Non–Neovascular Age–Related Macular Degeneration

Abstract

Abstract: : Purpose: To evaluate the relationship between ocular perfusion pressure (OPP) and visual function in patients with non–neovascular age–related macular degeneration (AMD). Methods: As part of a one–year randomized, double–masked, placebo–controlled trial, we evaluated the relationship between changes in ocular perfusion pressure and visual function, between baseline and the 12–month visit. Ocular perfusion pressure (OPP) was calculated using mean arterial blood pressure (MAP) and intraocular pressure (IOP) with OPP=2/3(MAP)–IOP. MAP was calculated using systolic (SBP) and diastolic (DBP) blood pressures with MAP=DBP + 1/3(SBP–DBP). Systolic (SOPP) and diastolic (DOPP) ocular perfusion pressure were also calculated where SOPP = SBP–IOP and DOPP = DBP–IOP. Blood pressure and heart rate were measured by automated sphygmomanometery. Best corrected visual acuity (BCVA) and contrast sensitivity (CS) were measured using an ETDRS chart and CSV–1000, respectively. Intraocular pressure was measured with Goldmann applanation tonometry. Correlation of ocular perfusion pressure and visual function parameters were analyzed using Pearson Correlation Coefficients. A p–value < 0.05 was considered statistically significant. Results: Twenty eight patients (Mean age 74.2+/–6.5; 17 females; 17 on placebo, 11 on dorzolamide) completed the one–year follow–up. Change in (Ch) BCVA correlated significantly with Ch OPP (r=0.39, p=0.040), Ch SOPP (r=0.38, p=0.047) and Ch MPP (r=0.39, p=0.041). No other correlations were found to be significant. Conclusions: The correlations between Ch BCVA and Ch OPP, Ch SOPP and Ch MPP were found to be positive and significant. This suggests a relationship between ocular perfusion pressure and visual acuity in patients with non–neovascular AMD and merits further study.

Keywords: age-related macular degeneration • visual acuity • blood supply