Researchers: No need to screen nonagenarians for diabetic retinopathy

By Laird Harrison

People over 90 years of age may not benefit from being screened for diabetic retinopathy, researchers say.

A review of 200 randomly chosen people in the United Kingdom eligible for screening at this age found that only 2 had been referred for further evaluation of diabetic retinopathy.

The screenings detected other ophthalmic conditions, but the researchers, from three centres in Birmingham, UK, suggest that “systematic annual screening may not be justified in this age group of patients, but rather be performed in optometric practice.” They published their findings in the journal Eye.

Diabetes mellitus is becoming more common in the United Kingdom, making diabetic retinopathy a common cause of blindness there. And the prevalence of diabetes is high among the elderly. Yet the incidence of diabetic retinopathy is relatively low in this population.

Some studies have shown that retinopathy does not progress as rapidly from the background to proliferative stages among the elderly.

With this background the researchers wanted to explore the utility of the National Health Service (NHS) Diabetic Eye Screening Programme recommendation that everyone with diabetes over the age of 12 years be screened annually for diabetic retinopathy.

So they searched the Digital Healthcare database of the Birmingham, Solihull and Black Country Screening Programme in April 2011. They randomly selected 200 people who were 90 years old or older and eligible for screening.

They found that 18 people did not attend routine screening and another 3 were not able to attend for medical reasons.

The remaining 179 attended at least one routine screening, with a mean of 2 screenings per person at a mean age of 91 years.

Fifty-seven percent of these people had no record of being screened before age 90. The others had their first recorded screening between ages 82 and 89 years. In the 45% of patients for whom records were available, the mean duration of diabetes at the time of their first screening was 10 years.

In the screenings of people aged 90 years and older, modal Snellen visual acuity for both eyes was 6/9. Clinicians referred 38 people (21%) for ophthalmology clinical assessment, but only 2 of them for diabetic maculopathy. One of those referred for diabetic maculopathy received focal laser treatment at the age of 91.

The other 36 were referred for other conditions: 4 for age-related macular degeneration (AMD), 3 for retinal vein occlusion, 1 for suspected glaucoma, 19 for images that could not be assessed due to cataract, 4 for images that could not be assessed due to asteroid hyalosis and 5 for images that could not be assessed due to technical failure. Of the 5 patients referred urgently, 4 had wet AMD and one had cataract with hand movement.

Of the 23 patients whose images could not be assessed, 20 were found to have no referable diabetic retinopathy upon subsequent ophthalmology clinical assessment, and the remaining 3 did not attend their appointment.

Of the 19 patients referred because cataracts prevented their images from being assessed, 5 subsequently had cataract surgery. Others chose not to have the procedure because they were satisfied with their vision or feared the risks.

The researchers said their findings paralleled others in the field. For example, Klein et al. (Diabetes Care 1992; 15: 1875-1891) found no proliferative retinopathy in a population over 80 years of age. And Stolk et al. (Diabetes 1995; 44:11-15) found that in a population of 6191 patients older than 55 years, none had proliferative retinopathy.

The authors of the current study conclude that screening for diabetic retinopathy effectively identifies important other ophthalmological conditions, and could be a way of restoring visual loss and maintaining the quality of life in people of 90 years of age.

But they point out that this is not the intended purpose of diabetic retinopathy screening. The 1% rate of detecting maculopathy in people over 90 in this study compares with a 5% rate in populations over age 12 years.

“It may be argued that it is more appropriate and cost effective for patients over 90 years of age to be encouraged to attend their optometrist on a regular basis rather than with the [diabetic retinopathy] screening programme,” they write.

Since they arbitrarily chose the age of 90 years as a cut off, they point out that more studies should be done to determine the utility of diabetic retinopathy screening at other ages.