Comparison of optometry vs digital photography screening for diabetic retinopathy in a single district

Abstract

Purpose To compare (a) the clinical effectiveness and (b) cost effectiveness of the two models in screening for diabetic retinopathy. Methods (a) Retrospective analysis of referral diagnoses of each screening model in their first respective years of operation and an audit of screen positive patients and a sample of screen negatives referred to the hospital eye service from both screening programmes. (b) Cost effectiveness study. Participants (1) A total of 1643 patients screened in the community and in digital photography clinics; (2) 109 consecutive patients referred to the Diabetic Eye Clinic through the two existing models of diabetic retinopathy screening; (3) 55 screen negative patients from the optometry model; (4) 68 screen negative patients audited from the digital photography model. Results The compliance rate was 45% for optometry (O) vs 50% for the digital imaging system (I). Background retinopathy was recorded at screening in 22% (O) vs 17% (I) (P ¼ 0.03) and maculopathy in 3.8% (O) vs 1.7% (I) (P ¼ 0.02). Hospital referral rates were 3.8% (O) vs 4.2% (I) Sensitivity (75% for optometry, 80% for digital photography) and specificity (98% for optometry and digital photography) were similar in both models. The cost of screening each patient was d23.99 (O) vs d29.29 (I). The cost effectiveness was d832 (O) vs d853(I) in the first year. Conclusion The imaging system was not always able to detect early retinopathy and maculopathy; it was equally specific in identifying sight-threatening disease. Cost effectiveness was poor in both models, in their first operational year largely as a result of poor compliance rates in the newly introduced screening programme. Cost effectiveness of the imaging model should further improve with falling costs of imaging systems. Until then, it is essential to continue any existing well-coordinated optometry model.

Accuracy of trained rural ophthalmologists versus non-medical image graders in the diagnosis of diabetic retinopathy in rural China

“…In the UK, optometrists using slit-lamp biomicroscopy following accreditation and assessment at a retinal clinic showed slightly lower sensitivity (0.75 vs 0.80) and identical specificity (0.98) compared with digital photography graded by an ophthalmologist. The reference standard was an experienced ophthalmologist who examined and graded the referrals from both screening methods using slit-lamp biomicroscopy 25. A study in Scotland compared the appropriateness of DR referrals among junior doctors who had received formal training in a DR clinic over 10–12 weeks to junior doctors who were comparable in terms of overall experience but had not received specialist ophthalmic instruction.…”

Development of a cost-effectiveness model for optimisation of the screening interval in diabetic retinopathy screening

“…DR is treated effectively with laser photocoagulation, although this has been found to be cost-effective only if retinopathy is detected before irreversible damages take place. 13,15,16 Therefore, in order for DR treatment to be cost-effective, diagnosis has to be timely, with published evidence showing that screening for STDR is highly cost-effective. [17][18][19][20]83 In the UK, results from published studies also highlight the cost-effectiveness of screening for DR, 84 with James et al 85 showing that a screening programme using retinal photography was cost-effective compared with opportunistic screening.…”

“…DR is treated effectively with laser photocoagulation, although this has been found to be cost-effective only if retinopathy is detected before irreversible damage takes place. 13,15,16 Therefore, in order for DR treatment to be cost-effective, diagnosis has to be timely. Published evidence has shown that screening for STDR is highly cost-effective.…”

Adherence to diabetic eye examination guidelines in Australia: the National Eye Health Survey

“…A study conducted in parallel in two geographically and logistically identical populations in the UK 820 compared the clinical and cost effectiveness of screening by a trained optometrist using slit lamp biomicroscopy compared to digital photography (non-mydriatic camera) following tropicamide instillation. Compliance with both screening models in their first years was equally poor at around 50% (Level III-2 evidence).…”