Ultrawide-Field Imaging for Assessing Diabetes Severity
JAMA Ophthalmology, January 2019
Substantial retinal pathology can exist beyond the 7 standard fields of the Early Treatment Diabetic Retinopathy Study (ETDRS), which include only about two-thirds of the retinal surface. Ultrawide-field (UWF) imaging allows for evaluation of up to 82% of the retinal surface in a single image. Aiello et al. looked at a large body of evidence to evaluate the reliability of UWF imaging relative to that of 7-field ETDRS for assessing the severity of diabetic retinopathy (DR). The authors observed exact agreement for 59% of eyes and agreement within 1 step for 97%—findings that may justify using UWF in future clinical trials.
For this cross-sectional study, the investigators included modified ETDRS 7-field images and UWF images captured with the Optos 200Tx system. All images were from adults with type 1 or type 2 diabetes (mean age, 62.2 years). Images were evaluated by trained graders who were masked to the clinical data. κ statistics were used to measure agreement among ETDRS 7-field images, UWF images, and UWF images masked to include only the ETDRS 7-field area.
Among the 742 eyes with graded ETDRS 7-field and UWF images, 359 (48.4%) initially had exact agreement and 653 (88.0%) had agreement within 1 step (weighted κ, 0.51). After open adjudication by an independent senior grader who examined all images that had a discrepancy of more than 2 steps, there was perfect agreement for 435 eyes (59.0%) and agreement within 1 step for 714 eyes (96.9%). Hence, concordance between the two imaging modalities was substantial (weighted κ, 0.77).
Of eyes that were 2 or more steps discrepant, 116 were available for adjudication. The ability of ETDRS and UWF masked images to accurately detect DR was considered similar for 59 eyes (50.9%), better with 7-field ETDRS for 22 eyes (19.0%), and better with UWF masked images in 31 eyes (26.7%). For 12.5% of eyes, the severity grade was at least 1 step higher with UWF unmasked versus UWF masked images. Predominantly peripheral DR lesions were present in 41.0% of eyes, indicating that the actual DR severity was at least 2 steps higher for 11.0% of eyes. Disparity for individual eyes was similar for these imaging modalities. (Also see related commentary by Stephen S. Feman, MD, in the same issue.)
The original article can be found here.