Perrier Manuel, Boucher Marie Carole, Angioi Karine, Gresset Jacques A, Olivier Sébastien
Hôpital Maisonneuve-Rosemont, Montreal, Que.
Can J Ophthalmol. 2003 Dec;38(7):569-74. doi: 10.1016/s0008-4182(03)80110-2.
The use of the nonmydriatic camera is gaining increasing acceptance for the detection of diabetic retinopathy when integrated into a community-tailored program. We performed a study to evaluate the optimal number and positioning of photographic fields necessary to screen for diabetic retinopathy with the Topcon CRW6 nonmydriatic camera.
In this prospective masked cross-sectional comparative study, we compared the assessment of diabetic retinopathy using two, three or four 45 degrees fundus images (centred respectively on the disc and the macula; on the disc, on the macula and temporal to the macula; and on the disc, on the macula, temporal to the macula and superotemporal to the macula, including the superior temporal vein) acquired with the Topcon CRW6 nonmydriatic camera, with the grading of the seven standard stereoscopic 30 degrees field photographs (7SF). The study population consisted of 98 consecutive adult patients known to have type 1 or 2 diabetes mellitus who presented for the first time to the diabetic retinopathy clinic of a tertiary care centre in Montreal. All patients underwent four nonmydriatic fundus photography sessions of both eyes, 7SF photography with pupil dilation and a complete ophthalmologic examination with pupil dilation by a retina specialist.
Compared to the 7SF, the sensitivity and specificity of screening for any retinopathy (Early Treatment Diabetic Retinopathy Study [ETDRS] grade greater than 10) using the two central fields were 95.7% and 78.1% respectively. The corresponding values with three image fields were 97.6% and 71.9%, and with four image fields, 97.6% and 65.6%. The sensitivity and specificity of screening for mild or worse disease (ETDRS grade 35 or greater) using the two central fields were 87.5% and 92.3%. The corresponding values with three image fields were 88.9% and 94.6%, and with four image fields, 88.9% and 91.9%. Poor image quality occurring with the addition of extra fields resulted in an increase of 6.2% in the rate of referral to an ophthalmologist. The use of two image fields missed no cases of retinopathy.
The use of image fields in addition to the two 45 degrees images centred on the disc and the macula on imaging with the Topcon CRW6 nonmydriatic camera did not significantly increase the sensitivity or specificity of screening for diabetic retinopathy. Contrary to the desired effect, the addition of fields resulted in diminished utility and cost-effectiveness of this screening approach.
将非散瞳相机整合到社区定制项目中用于检测糖尿病视网膜病变，日益受到认可。我们开展了一项研究，以评估使用拓普康CRW6非散瞳相机筛查糖尿病视网膜病变所需的最佳照相视野数量和位置。
在这项前瞻性双盲横断面比较研究中，我们比较了使用拓普康CRW6非散瞳相机获取的两张、三张或四张45度眼底图像（分别以视盘和黄斑为中心；以视盘、黄斑和黄斑颞侧为中心；以视盘、黄斑、黄斑颞侧和黄斑颞上侧为中心，包括颞上静脉）评估糖尿病视网膜病变的情况，与七张标准立体30度视野照片（7SF）的分级情况。研究人群包括98例连续的成年患者，他们已知患有1型或2型糖尿病，首次到蒙特利尔一家三级护理中心的糖尿病视网膜病变诊所就诊。所有患者均接受了双眼的四次非散瞳眼底照相、散瞳后的7SF照相以及由视网膜专科医生进行的散瞳后完整眼科检查。
与7SF相比，使用两个中心视野筛查任何视网膜病变（糖尿病视网膜病变早期治疗研究[ETDRS]分级大于10）的敏感性和特异性分别为95.7%和78.1%。三个图像视野的相应值分别为97.6%和71.9%，四个图像视野的相应值分别为97.6%和65.6%。使用两个中心视野筛查轻度或更严重疾病（ETDRS分级35或更高）的敏感性和特异性分别为87.5%和92.3%。三个图像视野的相应值分别为88.9%和94.6%，四个图像视野的相应值分别为88.9%和91.9%。额外视野导致图像质量不佳，使转诊至眼科医生的比例增加了6.2%。使用两个图像视野未漏诊任何视网膜病变病例。
在使用拓普康CRW6非散瞳相机成像时，除了以视盘和黄斑为中心的两张45度图像外，增加图像视野并不能显著提高糖尿病视网膜病变筛查的敏感性或特异性。与预期效果相反，增加视野导致这种筛查方法的实用性和成本效益降低。
