Abstract
Purpose: :
The cause of Epiretinal Membrane (ERM) in many cases is not known, however we do know that the prevalence varies in different ethnicities, with ERM being reported to be more common in Latinos and Malays. We had an opportunity in The Melbourne Collaborative Cohort Study (MCCS) to look at large numbers of two distinct ethnic groups, Australians of Southern and Northern European origin and to investigate various risk factors.
Methods: :
The MCCS, run by Cancer Council Victoria, Australia, is a prospective cohort study of 41,510 participants, investigating the role of diet and life style in the causation of common chronic diseases; study commenced in 1990. We conducted retinal photography at MCCS follow-up between 2003-2007 with CR6-45NM Canon Non-Mydriatic Digital Retinal Camera. For image grading, ERM was recorded as cellophane macular reflex (CMR) without retinal folds or preretinal macular fibrosis (PMF) with retinal folds. At the time of ERM grading, the participants were aged 48 to 86 years and 60% were female. 86% of participants were of Anglo-Celtic origin born in Australia or UK (Northern European origin) and 14% were first generation migrants from Mediterranean, predominantly from Greece or Italy (Southern European origin).
Results: :
A total of 22,406 participants were available for photography at follow up, of whom 21243 (95%) were eligible for ERM grading. ERM was present in 1882 (8.9%) cases; 1047 (4.9%) had CMR and 835 (3.9%) had PMF.In migrants from Southern Europe the prevalence of ERM was 14.4%, whereas in those of Northern European origin it was 7.5%. After adjusting for age, gender, diabetes, cholesterol level, BMI, waist-hip-ratio, Southern European ethnicity was strongly associated with ERM prevalence, with OR 1.95 (1.73, 2,19), p<0.001, for the effect of ethnicity on total ERM prevalence, OR 2.06 (1.75, 2.43), p <0.001, for PMF and OR 1.86 (1.60, 2.17), p<0.001, for CMR.
Conclusions: :
The prevalence of ERM in older Australians of Southern European origin is twice higher than among those of Northern European origin. Although CMR could be more readily visible against the more pigmented fundus of the Southern Europeans, detection of retinal folds (PMF) is less likely to be affected by fundus pigmentation. It may relate to difference in genes or lifestyle. These areas require further investigation.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • retina