Purpose: To compare diabetic retinopathy (DR) severity grading between Optomap ultrawide field scanning laser ophthalmoscope (UWFSLO) 200° images and an Early Treatment Diabetic Retinopathy Study (ETDRS) seven-standard field view.
Methods: Optomap UWFSLO images (total: 266) were retrospectively selected for evidence of DR from a database of eye clinic attendees. The Optomap UWFSLO images were graded for DR severity by two masked assessors. An ETDRS seven-field mask was overlaid on the Optomap UWFSLO images, and the DR grade was assessed for the region inside the mask. Any interassessor discrepancies were adjudicated by a senior retinal specialist. Kappa agreement levels were used for statistical analysis.
Results: Fifty images (19%) (P<0.001) were assigned a higher DR level in the Optomap UWFSLO view compared to the ETDRS seven-field view, which resulted in 40 images (15%) (P<0.001) receiving a higher DR severity grade. DR severity grades in the ETDRS seven-field view compared with the Optomap UWFSLO view were identical in 85% (226) of the images and within one severity level in 100% (266) of the images. Agreement between the two views was substantial: unweighted κ was 0.74±0.04 (95% confidence interval: 0.67-0.81) and weighted κ was 0.80±0.03 (95% confidence interval: 0.74-0.86).
Conclusion: Compared to the ETDRS seven-field view, a significant minority of patients are diagnosed with more severe DR when using the Optomap UWFSLO view. The clinical significance of additional peripheral lesions requires evaluation in future prospective studies using large cohorts.
Keywords: diabetes; diagnostic imaging; retina.