Retrobulbar blood flow in patients with cataract.

Abstract

To investigate retrobulbar haemodynamics in patients with cataract. Colour Doppler imaging of the ophthalmic artery was carried out on the eye scheduled for surgery in 30 patients with cataract and in one randomly selected eye of 100 healthy controls. The peak systolic velocity, mean velocity, end diastolic velocity and resistivity index in the ophthalmic artery were computed and adjusted for the influence of age and mean arterial pressure. Cataract type was recorded and lens opacity was measured with an opacity lensmeter. Odds ratio (OR) for cataract was analysed in a logistic regression model, depending on the adjusted blood-flow parameters, age and smoking status. The mean (SD) age was 45.5 (17.7) and 67.6 (5.8) years in controls and patients with cataract, respectively (p<0.001). The female to male ratio was 54:46 and 13:17, respectively (p = 0.41). Significant predictors of cataract in a forward stepwise logistic regression analysis were age (OR = 1.194; 95% confidence interval (CI) = 1.103 to 1.292; p<0.001), smoking status (OR = 14.119; 95% CI = 2.753 to 72.398; p = 0.002) and mean blood-flow velocity in the ophthalmic artery (OR = 0.731; 95% CI = 0.607 to 0.881; p = 0.001). Adjusted mean velocity was significantly lower in patients with cataract, even when only age-matched (age >55 years) non-smokers (31 controls, 19 patients with cataract) were considered (p = 0.003). Lens opacity and the type of cataract had no influence on the present findings. High mean velocity in the ophthalmic artery may be associated with a reduced risk of cataract.