Risk of macular degeneration with statin use should be interpreted with cautionBMJ 2001; 323 doi: https://doi.org/10.1136/bmj.323.7324.1308a (Published 01 December 2001) Cite this as: BMJ 2001;323:1308
- Redmer van Leeuwen, PhD student, department of epidemiology and biostatistics,
- Johannes R Vingerling, ophthalmologist, department of ophthalmology,
- Paulus T V M de Jong, professor, department of epidemiology and biostatistics
EDITOR—Hall et al in their study suggest a remarkable protective effect of cholesterol lowering statins on age related macular degeneration.1 Defined as the end stage of age related maculopathy according to an international classification and grading system,2 age related macular degeneration is a common, blinding disease in elderly people, and treatment options are limited. The economic potential of new drugs for this disease would be huge, and, if confirmed by other studies, the finding of Hall et alwould have far reaching effects on promoting and prescribing statins. It is therefore important to clarify this association before we accept the outcome. Several issues need to be discussed.
This cross sectional cohort study of 379 subjects included 27 (7%) people exposed to statins. The outcome, defined as both early and late age related maculopathy, was found in 20% of the cohort. Although a simplified grading method was used, this prevalence in those aged 66–75 years is compatible with other population based cohort studies.3 The expected number of subjects exposed and affected is therefore five, compared with the observed single subject. Although this is a significant correlation, we think that these small numbers warrant caution in the interpretation of the data.
The strong association between coronary artery disease and age related maculopathy that Hall et al found is not in accordance with previous studies. All population based cohort studies showed no association or a weak one between a history of cardiovascular disease and age related maculopathy.4
Also, the presumed positive association with cholesterol is not supported by the literature. Most studies found no association between cholesterol concentration and age related maculopathy or macular degeneration.4
Hall et al do not report the number of drugs that were selected and tested in the study. The number of different drugs used in the population is large, and the association with one of them may have been found by chance alone. Also, Hall et al do not specify whether the results include both current and previous use. Because of the cross sectional design, the small numbers and the resulting wide confidence interval, we think that the results should be interpreted with caution. Confirmation by larger, standardised, prospective studies is needed. These studies are under way.