Bilateral involvement by age related maculopathy lesions in a population

Aims - To describe the influences of age and sex on the frequency of bilateral age related macular degeneration (AMD) and age related maculopathy (ARM) lesions. Methods - The Blue Mountains Eye Study examined 3654 older Australians, 82% of permanent residents living in an area west of Sydney. Stereo macular photographs were graded for AMD (neovascuiar maculopathy and geographic atrophy) and early ARM lesions (soft drusen, reticular drusen, hyperpigmentation, and hypopigmentation). Results - Among 230 gradable cases of AMD or early ARM, 183 (80%) were bilateral. For AMD, 39/69 cases (57%) were bilateral, while for early ARM, 123/161 cases (77%) had signs in both eyes. Of the individual lesions, reticular drusen (91%) and indistinct soft drusen (79%) were most frequently present in both eyes. Geographic atrophy was bilateral in 56%, neovascular AMD in 40%, and distinct soft drusen in 47%, while hyperpigmentation was bilateral in 38% and hypopigmentation in only 28% of cases. A consistent age related increase in bilateral distribution was observed for most lesions. After adjusting for effects of age, current smoking, and AMD family history AMD and ARM component lesions, except for soft drusen, were more frequently bilateral in women. This sex difference was significant only for neovascular AMD, odds ratio 7.7 (95% confidence intervals 1.3-46.7). An AMD family history was more frequently reported in cases with bilateral involvement. Conclusions - This study has documented differences in the age related bilaterality of individual ARM components with higher bilateral rates for reticular or indistinct soft drusen compared with other lesions. The increased bilaterality of most ARM lesions among women is likely to contribute to the increased age adjusted risk of AMD blindness found in women.