Abstract
Purpose:
To estimate the prevalence, distribution and racial patterns of age-related macular degeneration (AMD) worldwide and project the number of people with AMD in 2020 and 2040.
Methods:
A systematic literature review was conducted to identify all population-based studies of AMD worldwide by a literature search of MEDLINE, EMBASE, and Web of Science databases. Only studies using standardized diagnosis schemes based on grading of retinal photos were included in the meta-analysis. Hierarchical Bayesian (HB) approaches, allowing for differences in study design effects, were used to determine the pooled prevalence (95% credible intervals [CrI]) of AMD, and examine the difference in prevalence by gender and three major ethnic groups (Europeans/Whites, Asians and Africans/Blacks). The number of people with AMD in 2020 and 2040 was projected based on the database from the United Nations World Population Prospects. The posterior probability (PP) of difference in prevalence was calculated, with PP close to 1.00 suggesting moderate evidence.
Results:
We identified a total of 38 studies, comprising of 125,353 individuals between 1989 and 2012. The pooled prevalence for any, early, and late AMD were 9.84% (95% CrI: 7.06%, 13.51%), 8.61% (95% CrI: 6.03%, 12.19%), and 0.65% (95% CrI: 0.41%, 1.01%), respectively. There was no evidence to support a difference in AMD by gender. Europeans were more likely to have AMD (any: 16.17%; early: 12.81%; late: 0.96%) than Asians (any: 4.88%, PP = 1.00; early: 3.70%, PP = 1.00; late: 0.45%, PP = 0.94;) and Africans (any: 5.88%, PP = 0.99; early: 5.68%, PP = 0.97; late: 0.16%, PP = 1.00). Asians were more likely to have late AMD than Africans (0.45% versus 0.16%, PP = 0.93). The projected number of people with any AMD and late AMD in 2020 is 195.49 and 9.33 million worldwide, respectively, increasing to 287.38 million, and 15.65 million respectively, in 2040.
Conclusions:
There will be nearly 200 million people with AMD globally in 2020, increasing to nearly 300 million in 2040. There is evidence for the difference in prevalence and pattern of AMD by racial/ethnic groups. These data provide for the first global estimates of one of the major causes of blindness in the world and has implications on the design and implementation of eye care service in different countries and regions.
Keywords: 412 age-related macular degeneration •
463 clinical (human) or epidemiologic studies: prevalence/incidence •
460 clinical (human) or epidemiologic studies: health care delivery/economics/manpower