Variations in Age and Gender in AMD Prevalence in Certain Patient Populations
In London, investigators aimed to obtain prevalence estimates of age-related macular degeneration
(AMD; late, geographic atrophy, neovascular) by age and gender among populations of European ancestry taking into
account study design and time trends.
They conducted a systematic review of population-based studies published by September 2010 with quantitative estimates of
geographic atrophy (GA), neovascular (NV) and late AMD prevalence. They identified studies by a literature search of MEDLINE
(from 1950), EMBASE (from 1980) and Web of Science (from 1980) databases. For their participants, they used data from 25
published studies (57,173 subjects: 455 with GA, 464 with NVAMD, and 1,571 with late AMD). The method used was Bayesian meta-regression of the log odds of AMD with age, gender and year of study allowing for differences in study design
characteristics to estimate prevalences of AMD (late, GA, NVAMD) along with 95% credible intervals (CrI). Main outcome
measures were log odds and prevalence of AMD.
The investigators reported that there was considerable heterogeneity in prevalence rates between studies; for late AMD,
20% of the variability in prevalence rates was explained by differences in age and 50% by study characteristics.
They also noted that prevalence of AMD increased exponentially with age (odds ratio [OR], 4.2 per decade; 95% CrI,
3.8–4.6), which did not differ by gender. There was some evidence to suggest higher risk of NVAMD in women compared
with men (OR, 1.2; 95% CrI, 1.0–1.5). The study investigators also found that compared with studies using fundus
imaging and international classification systems, studies using fundus imaging with alternative classifications were more
likely (OR, 2.7; 95% CrI, 1.1–2.8), and studies using alternative classifications without fundus imaging most likely
to diagnose late AMD (OR, 2.9; 95% CrI, 1.3–7.8). There was no good evidence of trends in AMD prevalence over
time. Estimated prevalence of late AMD is 1.4% (95% CrI, 1.0% –2.0%) at 70 years of age, rising to
5.6% (95% CrI, 3.9% –7.7%) at age 80 and 20% (95% CrI, 14% –27%) at age 90.
In conclusion, studies using recognized classifications systems with fundus photography reported the lowest prevalences of
AMD taking account of age and gender, and were stable over time, with a potentially higher risk of NVAMD for women. These
prevalence estimates can be used to guide health service provision in populations of European ancestry.