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

Background/aims: The objective of this study is to evaluate the accuracy and speed of trainees and experienced glaucoma specialists using the MatchedFlicker software against the manual examination of stereoscopic disc photographs for detecting glaucomatous optic disc change. Methods: Three experienced glaucoma specialists, two resident ophthalmologists and one glaucoma fellow from multiple institutions independently evaluated the same 140 image pairs from 100 glaucomatous/ocular hypertensive eyes using a handheld stereo viewer and the MatchedFlicker programme. Fifty had progression to glaucoma as determined by the Ocular Hypertension Treatment Study (OHTS) Optic Disc Reading Group and endpoint committee, and 50 more were negative controls for progression with photos taken a few minutes apart. Twenty photo pairs from each of the two groups were duplicated for reviewer variability analysis. The initial viewing method was randomised and then alternated for each group of 70 image pairs. Reviewer accuracy and evaluation time for each method were measured. Results: Evaluators averaged 8.6 s faster per image pair (26%) with the MatchedFlicker programme than with the stereo viewer (p=0.0007). Evaluators correctly identified more image pairs when using the MatchedFlicker software over the stereo viewer (p=0.0003). There was no significant difference between the expert and trainee group in speed or overall accuracy for either method. Experts were significantly more consistent than trainees with the duplicate image pairs (p=0.029). Trainees appeared more reluctant to designate eyes as showing glaucoma progression than experts. Conclusions: Both expert glaucoma specialists and ophthalmologists in various stages of training had greater accuracy and speed with the MatchedFlicker programme than with a handheld stereoscopic viewer.