The role of stereopsis in microsurgical performance on the EYESi ophthalmic surgical simulator

Introduction: There remains a lack of compelling objective evidence on whether stereopsis is necessary for an ophthalmic surgical career. It is also unclear if high-grade stereoacuity correlates with better surgical performance. The present study attempts to address this question by comparing the simulated surgical performance of subjects with different levels of stereoacuity using a virtual reality (VR) intraocular surgical simulator (EYESi, VRmagic, Mannheim, Germany). Methods: Subjects were tested based on their stereoacuity level and stratified in three age-matched groups: normal stereopsis, subnormal stereopsis, and patients with no measurable stereoacuity in the clinical setting. Eleven subjects in each group to make a total of 33 subjects with no prior surgical experience were recruited from the IWK Health Centre, Halifax, Canada (REB trial registration: 1023183). Subjects performed three attempts on a standardized microsurgical module on the EYESi VR simulator. Results: There was no significant main effect of the stereo-group that the participants belonged to on their total scores, or on the time needed to complete the task, or on the odometer value, or on the amount of injury to surrounding tissues. Discussion: This study showed that for a basic simulated microsurgical task on the EYESI intraocular surgical simulator, the performance of individuals with reduced and absent stereoacuity was statistically indistinguishable from those with normal stereoacuity. Therefore, caution is still recommended when advocating for mandatory high level of stereoacuity as a requirement for admission to training programs in ophthalmology. There is still definite need for solid evidence that stereopsis is necessary to achieve satisfactory skills in ophthalmic microsurgery.