Pseudoexfoliation as a risk factor for peripheral vascular disease: a case-control study

Aim To determine the association between pseudoexfoliation (PEX) and peripheral vascular disease (PVD) among age-related cataract. Setting Iladevi Cataract and IOL Research Center, Ahmedabad, India. Material and methods An observational age-matched case-control study of 160 patients over 60 years of age with age-related cataract. A total of 40 subjects with PEX (cases) were compared with 120 subjects with cataract but without PEX (controls). A detailed medical history, including hypertension, diabetes mellitus, cerebrovascular stroke and ischaemic heart disease, was recorded. Ankle brachial index (ABI) was used to determine the risk of PVD among age-related cataract patients. Color Doppler imaging was performed on the brachial and dorsalis pedis artery to measure ABI and detect PVD. Least mean ABI was the main outcome measure, as low ABI indicates higher risk for PVD. The lowest mean ABI was measured for each subject. An ABI ratio of <0.90 was considered abnormal. The Mann-Whitney U-test and logistic regression were used for analysis. Results The lowest mean ABI in the controls was 0.98 +/- 0.03 (SD; a range of 0.86-1.08) as compared with 0.88 +/- 0.02 (SD) among the cases (a range of 0.79-0.92; P < 0.001). When compared with controls, cases had a lower ABI (P < 0.001) irrespective of the presence or absence of systemic illness. On multiple regression analysis adjusting for systemic illness, the presence of PEX increased the odds of a low ABI group 150 times (P < 0.001). Conclusion Subjects with cataract and PEX had a significantly lower ABI as compared with controls (cataracts without PEX). PEX is associated with and may be a risk factor for PVD. Eye (2011) 25, 174-179; doi:10.1038/eye.2010.175; published online 3 December 2010