A new epidemiological study in vision loss and vision impairment, conducted by the Vision Loss Expert Group of the Global Burden of Disease (GBD) Study, and led by Professor Rupert Bourne, of the School of Medicine, Anglia Ruskin University, Cambridge, has shown a decrease in the prevalence of blindness and moderate and severe vision impairment (MSVI). The research, a comprehensive meta-analysis of data gathered from 46 separate studies, showed that for all ages between 1990 and 2015, age-standardised prevalence of blindness and MSVI decreased from 0.26% (0.10–0.46) to 0.15% (0.06–0.26) and from 1.74% (0.76–2.94) to 1.27% (0.55–2.17), respectively. The results of the study are expected to provide valuable information for the planning of future health care policy, and in identifying strategies that will continue to reduce the burden of blindness.
The data analyzed originated from multiple studies conducted in high-income countries, the Asia-Pacific region, Australasia, North America and countries in Western, Central and Eastern Europe. Results of the meta-analysis showed that in 2015, the number of individuals affected by the three categories of blindness, MSVI and mild vision impairment, were estimated at 70,000, 630,000 and 610,000, respectively, in Australasia. In North America the same three categories were estimated to be 980,000, 7.46 million and 7.25 million, while in Western Europe blindness, MSVI and mild vision impairment were estimated at 1.16 million, 9.61 million and 9.47 million, respectively. In addition, in 2015, cataract appeared to be the most common cause for blindness, followed by age-related macular degeneration (AMD), glaucoma, uncorrected refractive error, diabetic retinopathy (DR) and cornea-related disorders. Uncorrected refractive error appeared to be the leading cause of MSVI.
The Vision Loss Expert Group of the GBD Study aims to monitor the status of visual impairment and blindness every 5 years. The current study estimated that 66.6 million people were unable to see 6/12 in the better eye in 2015, and that this estimate is likely to rise to 69.0 million by 2020. The decrease in AMD, as a percentage of causes of blindness, is proposed to reflect the introduction of anti-VEGF medications, an innovation which has been relatively successful in reducing the burden of this age-related disorder. In concluding their analysis, the authors of the research state that, “[w]hile continuing to advance control of cataract and AMD as the leading causes of blindness remains a high priority, overcoming barriers to uptake of refractive error services would address approximately half of the MSVI burden. New data on burden of presbyopia identify this entity as an important public health problem in this population. Additional research on better treatments, better implementation with existing tools and ongoing surveillance of the problem is needed.” An account of the full study is published in the British Journal of Ophthalmology (doi: 10.1136/ bjophthalmol-2017-311258).