Detection of perimacular red dots and blots when screening for diabetic retinopathy: Refer or not refer?

Purpose: Detection of microaneurysms and/or microhaemorrhages near the fovea when screening for diabetic retinopathy poses a problem because referral to retinal specialists may alarm patients and unnecessarily burden ophthalmologists. Methods: Six-month prospective study of patients found to have minimal red lesions within one disc diameter of the fovea when screened for diabetic retinopathy. Two 45 degrees digital photographs, one centred on the macula and the other nasal including the optic disc, were taken for each eye. All patients received a 6-month re-screening appointment. Results: Out of 70 patients, 41 returned for re-screening. Diabetic retinopathy had worsened in 3 who required referral but no treatment, was unchanged in 19 and was undetectable in the other 19. Haemoglobin A1c decreased from 7.76%1.50% (61.3 +/- 16.2mmol/mol) to 6.93%+/- 1.7% (52.3 +/- 18.9mmol/mol) in the patients in whom diabetic retinopathy worsened but did not change in the other groups. Baseline haemoglobin A1c (p=0.048) and systolic blood pressure (p=0.007) were lower in the patients in whom diabetic retinopathy improved, but a multivariate model including haemoglobin A1c, blood pressure and known disease duration could not identify any independent risk factor. Conclusion: Minimal red lesions near the fovea, though commanding early re-screening, do not require immediate referral to retinal specialists.