Screening for DR must be extended

Detection and treatment of diabetic retinopathy has improved but battle not yet over

Dermot McGrath

Posted: Thursday, November 1, 2018

The introduction of systematic screening for sight-threatening diabetic retinopathy has been a major driver of improved detection and early treatment in Europe and worldwide over the past decade. The battle is far from over, however, with the global prevalence of diabetes mellitus expected to double by 2030, according to Simon Harding FRCS, FRCOphth.

“Unfortunately, there are still lots of people losing vision from diabetes and this is mainly due to poor engagement, late presentation, progression to advanced disease and to fragmented health services. The good news is that there are a lot of global initiatives being led by many organisations to try to address this,” he told delegates attending the 8th EURETINA Winter Meeting in Budapest.

Professor Harding, Chair of Clinical Ophthalmology at the University of Liverpool, United Kingdom, said that the system for screening for DR in the United Kingdom has developed considerably since the initial screening programme was first introduced in Liverpool in 1991.

“We started in Liverpool in 1991 before screening for DR had really been thought about. We are now covering a city population of about 450,000 in community centres using technician-based photography and grading. If people screen positive, they are then referred along to an ophthalmologist for determination of the presence or absence of sight-threatening DR and then for onward referral to the hospital,” he said.

The success of the Liverpool DR screening programme ultimately led to the approach being applied at a national level, said Prof Harding.

“In England we are now screening over 2 million people, equivalent to the entire diabetic population of England. We perform a two-to-three stage human grading with full quality assurance. Through the systematic approach we have made significant progress in the United Kingdom: diabetes has fallen to the fourth commonest cause of visual impairment in the last 10 years in people of the working age population. We like to believe that this is due to our screening programme,” he said.

While much has been achieved, the goal now is to emulate the achievement of Iceland, said Prof Harding, where there have been no cases of vision loss due to diabetes in the last 10 years. The focus has now turned to fine-tuning the screening system in place to make it more cost-effective, said Prof Harding.

“We are spending 80 million pounds a year in England to screen these individuals, and the rates of retinopathy are quite low so we are looking at the viability of extending the screening interval to biannually for people at low risk based on the previous and current retinal image,” he said.

“The team at Liverpool have also developed an variable interval approach adding early recall for people at higher risk and also including the most informative clinical risk factors of HbA1c, blood pressure and lipids.

“To optimise the approach, we have been testing a risk calculation engine to determine personalised risk for each individual patient, with the approach currently being validated in a randomised clinical trial,” said Prof Harding.