A systematic review and meta-analysis of over 20 years of data, published in the American Journal of Ophthalmology (http://dx.doi.org/10.1016/j.ajo.2014.06.012) and conducted by the Vision Loss Expert Group of the Global Burden of Disease Study, has identified a significant worldwide increase in blindness and vision impairment. The comprehensive review and analysis, conducted on all available population-based studies over a two-decade period, showed that the number of people who were blind due to macular diseases during the period from 1990 to 2010, increased by 36%, or 600,000 people, while those suffering vision impairment increased by 81%, or 2.7 million people. Such increases occurred against the backdrop of a global population increase of 30%. In a press release commenting on the results of the research, Professor Rupert RA Bourne, from Anglia Ruskin University, Cambridge, stated, “with the alarming prevalence of vision loss due to diabetes rising more than two-thirds in the past 20 years, the precipitous global epidemic of diabetes must be addressed.”
The research showed that in 2010, the number of blind people globally was 32.4 million, while the number classified as visually impaired was 191 million people. Blindness was classified as visual acuity < 3/60 and vision impairment was defined as visual acuity from < 6/18 to ≥ 3/60 due to macular diseases, excluding diabetic maculopathy. Of this population, 2.1 million were blind due to macular diseases while 6 million were visually impaired. The research found that macular diseases accounted for 6.6% of all blindness in 2010 and 3.1% of all vision impairment, worldwide. In the two-decade period under analysis, the study found, that the population blind or visually impaired due to macular diseases increased by over a third or 36%, while the visually impaired grouping increased by 81%.
The report on the analysis additionally stated that “of every 15 blind people, 1 was blind due to macular disease, and of every 32 visually impaired people, 1 was visually impaired due to macular disease”. Macular diseases were defined as “any disorder of the macula or posterior pole, except macular changes due to diabetic retinopathy.” Examples of such included AMD, myopic maculopathy and macular holes. In conducting the study, the research team identified 14,908 relevant papers between January 1980 and January 2012, of which 243 articles were deemed to be of sufficiently high-quality for use in the study. In the context of other leading causes of global vision impairment the authors stated that the number one cause of blindness globally was due to cataract and under-corrected refractive error, while macular diseases ranked in third position. In addition, women appeared to suffer a larger proportion of blindness and visual impairment caused by macular diseases compared to men, reflecting a similar finding in blindness and vision impairment due to cataract.