The global prevalence of diabetes is projected to reach 1.31 billion people by 2050 with the number of diabetic retinopathy cases increasing from 103.12 million in 2020 to 160.5 million by 2045 according to the research. In England and Wales, diabetic retinopathy consistently ranks as the main cause of vision loss.
Medical progress together with better diabetes treatment and routine retinopathy screenings since 2003 have decreased the situation where diabetic retinopathy becomes the dominant cause of vision loss. Early detection through tests helps prevent permanent vision loss before it happens. This research assesses trends in blindness certifications for diabetic eye disease in England and Wales between 2009 and 2020 while comparing data between both regions.
The certifications office at Moorfields Eye Hospital processes a certificate of vision impairment (CVI) forms with patient authorization for digitization and anonymized epidemiological research. The secure database holds processed information until April each year when annual certifications finish for national health service (NHS) financial purposes. The research team analyzed electronic certification data covering England and Wales from April 2009 up to March 2020.
Our initial examination included all vision-impaired individuals, while the subsequent analysis concentrated on diabetic eye health conditions. From 2009 to 2019 the NHS recorded data about patient age, gender, and ethnicity, but no data were collected for 2019-2020. The Welsh health boards received data recording beginning in 2014 because their previous system lacked the necessary specifications.
Severe sight impairment (SSI) disability evaluation requires individual test results below 3/60 of visual acuity(V/A) on the Snellen chart and substantial visual field reductions. People typically qualify for their sight impairment (SI) score which ranges from 3/60 to 6/60 or if their visual field shows a noticeable loss.
The project measured annual SI and SSI rates through certified data and population statistics then examined trend patterns with Poisson regression. Patients and the public were not involved in the study.
During the study period, the typical age of people with vision impairment due to diabetic retinopathy decreased for both England and Wales from 67 to 62 years. In England, 70% of the population identified as White while the remaining 15% were either Black or Asian. Wales had significantly higher percentages of White residents at 80% to 90%. Sex distribution in England showed minimal variation among men and women, whereas in Wales, males accounted for 61% of cases.
From 2009-2020 England experienced a steady drop-in certification rate from 43.4 to 41.7 instances per 100,000 citizens (p < 0.001). Wales reported mixed findings with lower rates from 50.6 to 40.1 then increased to 51.8 while showing no clear pattern of change (p = 0.087). Wales reported more certifications than England with 9% more total deaths due to elevated activity within one health board.
Medical certifications related to diabetic retinopathy decreased substantially in England from 72.8 to 41.3 per 100,000 population (p < 0.001). Wales recorded a more drastic drop of 49% in the first five years, which then stabilized at a final rate of 55.5 in 2020. Certified patient outcomes decreased consistently throughout both countries without showing important differences in their results.
During the decade from 2009/2010 to 2019/2020 England saw substantial decreases in both types of vision impairment (SI and SSI) and new certifications for all causes. In Wales, certification numbers initially dropped sharply and then began to rise reaching the highest level during 2019/2020.
The certification process shows limitations because doctors report fewer cases than actual conditions and vary their testing methods while mainly assessing sight quality instead of peripheral vision. The objective of Wales’ new optometry contract is to cut obstacles and generate more precise information about vision impairment recognition rates.
This research analyzed the development of sight impairment and severe sight impairment certification numbers in England and Wales focusing on diabetes-related cases. The number of certifications dropped across both regions but decreased primarily in England, while Wales initially saw a decrease followed by a gradual increase. The differences between health authority data show that existing certification methods need improvement for better measurement.
References: Thomas R, John R, Bunce C, et al. Trends in certifications of overall vision impairment and that due to diabetic retinopathy/maculopathy in England and Wales, 2009/2010 to 2019/2020: a retrospective database analysis. BMJ Open. 2025;15:e090597. doi:10.1136/bmjopen-2024-090597
