Abstract
Purpose :
Current diabetic retinopathy screening methods are costly, require highly specialized personnel and patient mydriasis. The new Optos® apparatus can be operated by non-specialists and provides ultra wide-field imaging, with 200° views of the retina in a single image. Conventional methods only provide 90° image views of the retina in up to 16 images. We aimed to validate the Optos® imaging against conventional Topcon® imaging for grading retinopathy.
Methods :
We conducted a follow-up study of 101 persons with diabetes who participated in the Addition-DK study. Retina fundus photos using both Optos® and Topcon® imaging were taken for both eyes among all participants. All photos were graded by specialist ophthalmologic nurses, using an adaptation of the Early Treatment Diabetic Retinopathy Scale (ETDRS). We constructed frequency tables separately for peripheral- and macular grading. Levels of agreement between the grading of Optos® and Topcon® images were assessed using weighted Kappa statistics, separately for peripheral and macular imaging
Results :
Using Optos® imaging, a larger proportion of the peripheral grading was determined “grade 1” or “grade 2”compared with Topcon® (Figure 1). The inter-camera agreement was substantial (0.63 (95%CI: 0.39-0.87)) for macular retinopathy and fair (0.30 (95%CI: 0.16-0.44)) for peripheral retinopathy (both with a P-value<0.001).
Conclusions :
The inter-camera agreement was acceptable for macular retinopathy, but only fair for peripheral retinopathy, with the Optos® apparatus finding more microvascular changes in the periphery than the conventional Topcon® apparatus. Whether this has any clinical significance remains to be explored.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.