Incidence of age-related macular degeneration in the central region of Portugal: the Coimbra Eye Study – report 5

Abstract

Purpose : AMD is the leading cause of irreversible visual impairment in the elderly in developed countries, therefore, incidence population-based studies in AMD are vital in planning for demand in health care systems. The purpose of this study is to describe the 6.5-year incidence and progression of early and late AMD in a coastal town in the central region of Portugal.

Methods : Population-based cohort study. Participants underwent standardized interviews and ophthalmologic examination, including digital fundus imaging. Colour fundus photographs were graded according to the International Classification and Grading System for AMD and ARM from the International ARM Epidemiological Study Group. The crude and age-standardized incidence of early and late AMD was calculated, and progression was analysed.

Results : The overall 6.5-year cumulative incidence of early AMD was 10.7%, and that of late AMD was 0.8%. The incidence of early AMD was 7.2%, 13.1% and 17.7%, for participants aged 55 to 64 years, 65 to 74 years and 75 to 84 years (p<0.001). Late AMD incidence was 0.3%, 0.9% and 2.8% for the corresponding age groups (p=0.003). Age-standardized incidence was 10.8% (95%CI, 10.74%-10.80%) for early and 1.0% (95%CI, 1.00%-1.02%) for late AMD. The incidence of NV-AMD and GA was 0.4%, for both late forms. Progression was found in 17.2% of patients.

Conclusions : This study documents the incidence and progression of AMD in a coastal town in central Portugal, a Mediterranean country from Southern Europe. Early AMD incidence was found to be similar to major epidemiologic studies of European-descent populations, however the incidence of late AMD was lower suggesting the value of further analysis of genetic, nutritional and environmental risk factors in this population.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.