Clinical Profile and Risk Factors of Exudative Age-related Macular Degeneration: A Hospital Based Case-control Study

Abstract

Introduction: Age-Related Macular Degeneration (ARMD) is one of the leading causes of vision loss in the elderly population. ARMD is characterised by progressive degeneration of the retinal pigment epithelial complex and photoreceptors primarily in the macular region of the retina. The prevalence of ARMD in India ranges from 39.5% to 0.3%, as reported in populationbased studies. Numerous risk factors, both modifiable and nonmodifiable, have been identified for this condition. Aim: To determine the clinical profile and risk factors associated with exudative ARMD. Materials and Methods: This is a case-control study conducted in a tertiary eye care hospital in South Kerala from June 2011 to June 2012. The cases were patients attending the Outpatient Department (OPD) and Retina clinic who were diagnosed with wet ARMD. The corresponding control is the next patient seen after the case who is of the same sex and comparable age. Data were analysed using the Statistical Package for Social Sciences (SPSS) version 17.0. Chi-square test was used to elucidate the association between the presence of ARMD and diet, educational status, occupation, smoking, alcoholism, hypertension, diabetes mellitus, cardiovascular disease, obesity, hyperlipidemia, history of cataract surgery, and cataract. Multivariate logistic regression analysis was used to assess these risk factors for cases and controls. Results: A total of 130 subjects consisting of 65 cases and 65 controls participated in the study. The majority of patients were in the age group of 60-69 years. History of hyperlipidemia (Odds Ratio [OR]: 1.649, Confidence Interval [CI]: 0.524-5.191, p=0.042) was significantly associated with the development of exudative ARMD. Hypertension (OR: 1.398, CI: 0.694-2.815, p=0.051), cardiovascular disease (OR: 1.770, CI: 0.274-5.064, p=0.188), Body Mass Index (BMI) >25 (OR: 0.537, CI: 0.254- 1.133, p=0.075), dietary factors (OR: 1.351, CI: 0.461-3.961, p=0.609), smoking (OR: 1.400, CI: 0.484-4.051, p=0.593), alcoholism (OR: 1.400, CI: 0.484-4.051, p=0.593), history of cataract surgery (OR: 1.160, CI: 0.411-3.279, p=0.456), cataract (OR: 1.618, CI: 0.692-3.782, p=0.149) were not found to be significant. The results may vary in the present scenario due to changes that have occurred over the years, especially in the case of smoking and alcoholism, as the prevalence of which has increased. The majority (88.75%) of study subjects have classic Choroidal Neovascular Membrane (CNVM). Conclusion: ARMD was found to have a significant association with hyperlipidemia. Those with hypertension, cardiovascular disease, cataract, smokers, and alcoholics have a higher risk of developing exudative ARMD. By controlling modifiable risk factors like hyperlipidemia and by avoiding smoking and alcoholism, the authors can prevent this potentially blinding condition to some extent.