Effect of the COVID-19 pandemic on diabetic retinopathy and referral levels in the English National Health Service Diabetic Eye Screening Programme

Aims: The aim was to determine the effect of the COVID-19 pandemic on diabetic retinopathy and referral rates in the English National Health Service (NHS) Diabetic Eye Screening Programme (DESP).

Methods: Non-patient identifiable data are submitted centrally from the 57 regional centres in the NHS DESP on a quarterly basis and analysed using STATA, comparing 01/04/2019-31/03/2020 and 01/04/2021-31/03/2022. Patient characteristics were analysed from National Diabetes Audit (NDA) data.

Results: There were 2,274,635 grades from the 57 centres in 2019-2020 and 2,199,623 grades in 2021-2022. The proportion of eyes with referable DR increased from 3.1% in 2019-2020 to 3.2% in the 2021-2022 NHS year (p < 0.01) with a small increase in the level of non-referable DR from 24.6% to 24.8% (p < 0.01). The median proportion of ungradable eyes in 2019-2020 was 2.6% (IQR: 2.3% to 3.3%) increasing to 3.1% (IQR: 2.5% to 3.7%) in 2021-2022. NDA data demonstrated that the proportions with type 1 diabetes receiving eye screening were higher in the latter year (8.3% vs. 7.3%).

Conclusion: The COVID-19 pandemic was associated with small increases in referable retinopathy rates from 3.1% to 3.2%, non-referable DR from 24·6% to 24.8% and an increase in the ungradable image rate from 2.6% to 3.1%, the latter increase possibly being caused by untreated cataract during the pandemic. Risk stratification of invitations in the recovery period was believed to have contributed to keeping the referable rates low and supports a similar approach in extension of the screening interval for low-risk groups.