RISK-FACTORS FOR ISCHEMIC OCULAR MOTOR-NERVE PALSIES

Objective: To identify risk factors associated with neurologically isolated ischemic ocular motor nerve palsies. Design: Case-control study. Setting: Multispecialty clinic providing primary, secondary, and tertiary care in central and northern Wisconsin. Study Participants: After applying strict, predetermined, inclusion and exclusion criteria to the medical records of patients with ocular motor nerve palsies, 65 case patients 50 years of age or older were identified with ischemic ophthalmoplegia. A control subject, matched for sex and exact year of age, was randomly selected for each case patient from individuals undergoing a comprehensive medical evaluation. Main Outcome Measures: Prevalence of potential risk factors in case patients and controls, including diabetes, hypertension, hypercholesterolemia, coronary artery disease, left ventricular hypertrophy, adiposity, tobacco use, prior ocular motor nerve palsy, and hematocrit. Risk factors were assessed using standardized definitions. Results: After adjustment for potential confounding factors, significant risk factors and their associated odds ratios (ORs) and 95% confidence intervals (CTs) were as follows: previously diagnosed diabetes, OR=5.75 (CI=1.68 to 19.7); left ventricular hypertrophy, OR=5.20 (CI=1.30 to 20.82); and, hematocrit (per percentage increase), OR=1.35 (CI=1.13 to 1.61). Conclusion: In addition to the generally accepted risk factor of diabetes, left ventricular hypertrophy and elevated hematocrit appeared to be important determinants of ischemic ocular motor nerve palsy. Additional studies should be undertaken to confirm these findings.