Comparing Glaucomatous Disc Change Using Stereo Disc Viewing and the MatchedFlicker Software Program in Ophthalmologists-in-Training

Abstract

Purpose To compare the accuracy and speed of using the computerized MatchedFlicker® software program to evaluate glaucomatous optic disc change against the traditional gold-standard of manually examining stereoscopic disc photographs. Design A prospective evaluation of diagnostic technology. Methods Two resident ophthalmologists and one glaucoma fellow at the University of Florida independently evaluated 140 image-pairs from 100 glaucomatous/ocular hypertensive patient eyes using a handheld stereo-viewer and the MatchedFlicker® program. Fifty had progression to glaucoma as determined by the OHTS Optic Disc Reading Group and the OHTS end-point committee in the Ocular Hypertension Treatment Study (OHTS), and fifty more had photos taken a few minutes apart which were negative controls with no progression. Twenty photo-pairs from each group were duplicated to determine reviewer variability. Photos were examined in alternating blocks of 70 photo pairs for each method, with the starting viewing method randomized. Reviewer accuracy and time to review for each method were measured. Results Using the handheld stereo-viewer, the reviewers correctly identified progression or non-progression in 76.0% of the slide-pairs. Using the MatchedFlicker® software 87.6% were correctly identified (p=0.011). Evaluator speed averaged 34.1 seconds per image-pair with the stereo-viewer verses 24.9 seconds with the MatchedFlicker® program (p=0.044). Overall, Flicker was significantly more specific but less sensitive than stereo slides. Trainees appeared more reluctant to identify glaucoma progression for slides than Flicker. For the two less experienced trainees Flicker was significantly more accurate. Conclusion The MatchedFlicker® software had a greater accuracy and was quicker to perform than using a handheld stereoscopic viewer.

Optic Disc Image Subtraction as an Aid to Detect Glaucoma Progression

“…However, the identification of glaucomatous optic nerve change is only a part of the bigger clinical picture for each patient and should be used along with all the other modalities. To reach this goal, as stated in previous studies, 32 we believe that ancillary tests in glaucoma should have higher specificity (the percentage of negative designations that are truly negative) rather than higher sensitivity (the proportion of positive diagnoses that are truly positive) because of the low incidence of progression in eyes under treatment. In our study, the overall specificity was 85%.…”

“… 26 – 30 Reus and associates 20 found that the accuracy of diagnosing glaucoma by reviewing stereoscopic optic disc photographs to be at best 81%. New computer software such as matched flicker software programs 31 , 32 or optic disc photograph subtraction proposed in this study could assist clinicians in highlighting possible changes of the optic nerve head.…”

Comparing glaucomatous disc change using stereo disc viewing and the MatchedFlicker programme in glaucoma experts and trainees

“…In our previous study, we found that Flicker was more accurate, specific and time efficient than stereophoto examination for ophthalmologists in training 6. Our current study also includes data from academic glaucoma experts from three centres to examine the efficacy of implementing Flicker into clinical practice where stereophoto disc review is already an integral part of patient care.…”

“…As we described in our previous paper,6 50 optic nerve head (ONH) image pairs serving as positive controls were identified from 50 patients in the OHTS study that showed disc progression as determined by the OHTS Optic Disc Reading Group of the Bascom Palmer Eye Institute and confirmed as glaucomatous change by the OHTS endpoint committee.…”

“…In our original study, we compared the two techniques using non-expert trainee observers in various stages of their ophthalmology training 6. For these trainees, the Flicker technique was both more accurate and time efficient when compared with stereo photos.…”