Owens D R, Gibbins R L, Lewis P A, Wall S, Allen J C, Morton R
Diabetes Research Unit, UWCM, Academic Centre, Llandough Hospital and Community NHS Trust, Penarth, South Glamorgan, UK.
Diabet Med. 1998 Feb;15(2):170-5. doi: 10.1002/(SICI)1096-9136(199802)15:2<170::AID-DIA518>3.0.CO;2-H.
In order to assess the relative ability of general practitioners (GPs) to detect diabetic retinopathy (DR), especially sight-threatening diabetic retinopathy (STDR) by direct ophthalmoscopy or by examining, on a separate occasion, retinal images as 35 mm colour transparencies, a South and Mid Wales primary care-based study was performed in four general practices (six GPs). The participating GPs were provided with standardized training and equipment. Both methods were compared to the 'reference' grade of DR provided by the Diabetic Retinopathy Reading Centre (London), based on the same retinal images. Ophthalmoscopy and retinal photography (Canon CR4 45NM) with mydriasis were all practice based. The clinical assessments were based on a protocol developed for screening for DR in Europe. A total of 996 people with diabetes were identified, representing a prevalence of known diabetes of 2.1%. After exclusions on medical grounds, 897 patients were available for screening, of whom 605 (68%) were photographed. Based on the retinal images, the reference centre identified DR in 43% and STDR in 14.4%. In total, 597 valid comparisons between GPs and the reference centre were obtained; of these, 462 (77%) were high quality photographs which were used in subsequent analysis. The sensitivity for detecting any DR increased from 62.6% (95% CI 55.9-69.4) with ophthalmoscopy to 79.2% (95% CI 73.6-84.9) using retinal photographs, specificity remaining essentially unchanged at 75.0 (95% CI 69.5-80.5) and 73.5% (95% CI 68.0-79.1) with the positive predictive value (PPV) increasing from 67.2 (95% CI 60.4-74.0) to 71.0% (95% CI 65.0-77.0), respectively. The detection of STDR sensitivity increased from 65.7 (95% CI 54.4-77.1) with ophthalmoscopy alone to 87.3% (95% CI 79.4-95.2) based on retinal photographs with specificity falling from 93.8 (95% CI 91.4-96.3) to 84.8% (95% CI 81.2-88.5) and PPV from 65.7 (95% CI 54.4-77.1) to 51.2% (95% CI 42.1-60.3), respectively. We conclude that the use of standardized 35 mm colour transparency retinal photographs for screening by trained GPs in a primary care setting achieves an acceptable detection rate (>87%) for STDR, contrasting with ophthalmoscopy alone (66%), which was below the proposed UK standard of 80%.
为评估全科医生（GP）通过直接检眼镜检查或在不同时间检查35毫米彩色透明视网膜图像来检测糖尿病视网膜病变（DR），尤其是威胁视力的糖尿病视网膜病变（STDR）的相对能力，在南威尔士和中威尔士的四个全科医疗诊所（六位全科医生）开展了一项基于基层医疗的研究。为参与研究的全科医生提供了标准化培训和设备。将这两种方法与糖尿病视网膜病变阅读中心（伦敦）基于相同视网膜图像给出的DR“参考”分级进行比较。检眼镜检查以及散瞳后的视网膜摄影（佳能CR4 45NM）均在诊所内进行。临床评估基于欧洲制定的DR筛查方案。共识别出996例糖尿病患者，已知糖尿病患病率为2.1%。经医学原因排除后，897例患者可进行筛查，其中605例（68%）接受了拍照。基于视网膜图像，参考中心识别出43%的患者患有DR，14.4%的患者患有STDR。全科医生与参考中心之间总共获得了597次有效比较；其中，462次（77%）是高质量照片，用于后续分析。检测任何DR的敏感性从检眼镜检查时的62.6%（95%可信区间55.9 - 69.4）提高到使用视网膜照片时的79.2%（95%可信区间73.6 - 84.9），特异性基本保持不变，分别为75.0%（95%可信区间69.5 - 80.5）和73.5%（95%可信区间68.0 - 79.1），阳性预测值（PPV）分别从67.2%（95%可信区间60.4 - 74.0）提高到71.0%（95%可信区间65.0 - 77.0）。仅通过检眼镜检查检测STDR的敏感性为65.7%（95%可信区间54.4 - 77.1），基于视网膜照片则提高到87.3%（95%可信区间79.4 - 95.2），特异性从93.8%（95%可信区间91.4 - 96.3）降至84.8%（95%可信区间81.2 - 88.5），PPV从65.7%（95%可信区间54.4 - 77.1）降至51.2%（95%可信区间42.1 - 60.3）。我们得出结论：在基层医疗环境中，由经过培训的全科医生使用标准化的35毫米彩色透明视网膜照片进行筛查，对STDR可实现可接受的检测率（>87%），相比之下仅用检眼镜检查的检测率为66%，低于英国提议的80%标准。
