Abstract
Purpose: :
Accurate assessment of optic disc edema is necessary when managing a range of optic nerve pathology, including papilledema, ischemic optic neuropathy, optic neuritis, and papillitis. Here, we compare inter-observer agreement using a novel automated alternation flicker technology with side-by side digital photography inspection for evaluation of optic disc edema.
Methods: :
Patients with optic disc edema and at least one pair of serial digital optic disc photographs were included, for a total of 68 photos of 24 eyes from 12 patients. Using side-by-side digital photograph comparison, optic disc edema was judged to have improved, remained stable, or worsened by a single observer during the course of regular clinical care. Next, the photographs were grouped into 42 sequential pairs. 3 graders, masked to image chronology, then evaluated the photograph pairs using automated alternation flicker (EyeIC, Narberth, PA, USA) as stable, improved, or worsened. The order of patients was randomized. Inter-observer agreement was assessed using the kappa statistic. Agreement between the masked observers using automated alternation flicker and the observer using side-by-side comparison was assessed using the kappa statistic.
Results: :
The three masked observers demonstrated near-perfect agreement when evaluating optic disc edema as improved, stable, or worsened using automatic alternation flicker (Overall agreement 92%, fixed-marginal kappa 0.84). The three masked observers using automated alternation flicker showed only fair agreement with the observer using side-by-side comparison (overall agreement 71%, fixed-marginal kappa 0.40) More cases of worsened optic disc edema were identified by the automated alternation flicker observers (n=2 for all three observers) than by the side-by-side digital image comparison observer (n=0). Similar numbers of stable (n=16, 16, 13) and improved (n=24, 24, 27) optic disc edema were identified by the automated alternation flicker group compared to the side-by-side image comparison observer (n=15 stable, n=27 improved).
Conclusions: :
Automated alternation flicker has a high degree of inter-observer agreement when used to evaluate optic disc edema, and only a fair level of agreement with side-by-side image comparison. Automated alternation flicker may be a more accurate tool for identifying changes in optic nerve head edema during serial exams than side-by-side digital optic nerve photograph comparison.
Keywords: neuro-ophthalmology: optic nerve • neuro-ophthalmology: diagnosis • optic disc