Jane Scheetz PhD1, 2, 3 Konstandina Koklanis PhD1 Myra McGuinness PhD2, 3 Maureen Long PhD1 Meg E Morris PhD1, 4
1 Department of Community & Clinical Allied Health, La Trobe University, Melbourne, Australia
2 Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
3 Ophthalmology, University of Melbourne, Department of Surgery
4 North Eastern Rehabilitation Centre, Healthscope, Ivanhoe, Australia
Aim: To examine the extent to which level of clinical experience of orthoptists influences eye movements, gaze behaviour and diagnostic accuracy when examining optic disc images for glaucoma.
Methods:Eye movements and gaze behaviour of participating orthoptists were recorded whilst examining 20 optic disc images for signs of glaucoma. A maximum of 90 seconds was given per image to perform the examination. At the conclusion of each examination, participants were asked to determine whether it was unlikely, possible, probable or certain that the optic disc image had glaucoma. The main outcome measures were examination time, number of fixations, time spent on areas of interest, gaze behaviour and glaucoma likelihood agreement between orthoptist groups.
Results: A total of 41 orthoptists (36 novices and 5 glaucoma specialist orthoptists) agreed to participate. Using multivariable linear regression, there was no difference in optic disc examination times between orthoptist groups or for the total number of fixations made. Those with more experience made significantly more fixations when assessing images with possible signs of glaucoma (p = 0.024). Glaucoma specialist orthoptists methodically examined the optics disc, visualising areas most likely to display glaucomatous damage. Novice orthoptists displayed random gaze behaviours and spent more time looking at areas less likely to display change. Glaucoma likelihood agreement was higher for glaucoma specialist orthoptists (K = 0.51) compared to novices (K = 0.31).
Conclusion: Glaucoma specialist orthoptists adopt a systematic gaze behaviour when examining the optic disc for glaucoma and achieved higher agreement when determining glaucoma likelihood.