Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care

Abstract Objective: To evaluate whether adding retinal photography improved community screening for diabetic retinopathy. Setting: Mobile screening unit at rural and urban general practices in south west England. Subjects: 1010 diabetic patients from primary care. Design: Prospective study; patients were examined by ophthalmoscopy by general practitioners or opticians without fundal photographs and again with photographs, and assessments were compared to those of an ophthalmologist. Main outcome measures: Whether fundal photography improved the sensitivity of detection of retinopathy and referrable diabetic retinopathy, and whether this sensitivity could be improved by including a review of the films by the specialist. Results: Diabetic retinopathy was detected by the ophthalmologist in 205 patients (20.5%) and referrable retinopathy in 49 (4.9%). The sensitivity of the general practitioners and opticians for referrable retinopathy with opthalmoscopy was 65% and improved to 84% with retinal photographs. General practitioners' sensitivity in detecting background retinopathy improved with photographs from 22% to 65%; opticians' sensitivity in detecting background retinopathy improved from 43% to 71%. The sensitivity of detecting referrable retinopathy by general practitioners improved from 56% to 80% with photographs; for opticians it improved from 75% to 88%. Conclusion: Combining modalities of screening by providing photography with specialist review of all films in addition to direct ophthalmoscopy through dilated pupils improves assessment and referral for diabetic retinopathy by general practitioners and opticians. With further training and experience, primary care screeners should be able to achieve a sensitivity that will achieve an effective, acceptable, and economical community based screening programme for this condition. Key messages Ophthalmoscopy alone in primary care misses early diabetic retinopathy and is insensitive as a screening modality Using photography in addition to ophthalmoscopy, general practitioners and opticians can increase the correct and early diagnosis of sight threatening and background retinopathy The sensitivity of screening is further improved by having a specialist assess the photographs This method is highly cost effective: it costs £12.50 per patient screened to provide photographs—an estimated £1100 per patient whose sight is saved