Abstract
Purpose: To review the literature to determine if new technologies have reduced the need for dilation in a Diabetic Eye Screening Programme
Methods: Two approaches were used:
- A review of the literature relating to screening for diabetic retinopathy that has been on-going by the second author (PHS) since March 2000. The results are held in Endnote which was subsequently searched using keywords.
- Our local library conducted a search using a combination of keywords and subject headings were used to formulate search strategies on Medline (Ovid), Embase (Ovid), CINAHL (EBSCO), and the Cochrane Library
Results: A total of 133 articles were identified, separated into 117 original articles and 16 review articles. After discarding those that did not appear relevant, 76 original articles and 15 reviews remained. These were analysed to determine whether they helped to answer the main question, and 49 references have been quoted. The sensitivities and specificities of mydriatic digital photography for detection of referable diabetic retinopathy have been consistently high since the early studies with sensitivities of >80% and specificities of > 85% against recognised reference standards in the majority of studies. The specificity achieved is often above 90% if ungradable images are not counted as test positive. Non-mydriatic digital photography performs well in those in whom gradable images can be obtained. In Scotland, which has a long history of performing staged mydriasis, they currently dilate 30% of their screened population. This has risen slowly from 24% in 2002 because of increasing ageing of the population which is one of the risk factors for poor quality images.
Recent studies using confocal technology have demonstrated that the percentage of ungradable images without eye drops can be reduced to under 5.1% and after staged mydriasis to under 3.4%. This will depend on the age group and the percentage of untreated cataract in the population.
Conclusions: The results of this review are encouraging that, with the development of less expensive confocal cameras, this technology is likely to be used routinely in diabetic eye screening programmes around the world using staged mydriasis.