Screening for diabetic retinopathy and reduced vision among Indigenous Australians in Top End primary care health services: a TEAMSnet sub-study

Background: Diabetic retinopathy (DR) prevalence is higher in Indigenous Australians than in other Australians and is a major cause of vision loss. Consequently, timely screening and treatment is paramount, and annual eye screening is recommended for Indigenous Australians. Aims: To assess the prevalence of DR, reduced vision and DR treatment coverage among Indigenous Australian adults with diabetes attending Top End indigenous primary care health services. Methods: A cross-sectional DR screening study conducted from November 2013 to December 2015 in two very remote Northern Territory Aboriginal primary healthcare services. Results: In 287 subjects, the prevalence of non-proliferative DR, proliferative DR and clinically significant diabetic macular oedema was 37.3%, 5.4% and 9.0% respectively. Treatment coverage for PDR was 60% (of 10 patients) and for CSMO was 17% (of 23 patients). Vision data were available from 122 participants at one site. The proportion with normal vision, reduced vision, impaired vision and blindness was 31.1%, 52.5%, 15.6% and 0.8% respectively. Overall, ungradable monocular image sets (46%) were associated with poorer quality images and missing protocol images (both P < 0.001). Ungradable images for DR were associated with presence of small pupils/media opacities (P < 0.001). Ungradable images for diabetic macular oedema were associated with poorer image quality (P < 0.001), cataracts (P < 0.001) and small pupils (P = 0.04). Conclusions: A high prevalence of DR, CSMO and impaired vision was noted in Indigenous Australians with diabetes. Screening in primary care is feasible, but more effective screening methods are needed.