Impact of stereoacuity on simulated cataract surgery ability

There exists a long-standing perception that diminished stereoacuity has a detrimental effect on microsurgical ability and skills acquisition. This has potential implications on the enrolment of surgical trainees into ophthalmology and other microsurgery specialities. However, strong evidence in this area is lacking. This case-control study aims to establish the exact level of stereopsis impairment at which a statistical drop in surgical performance occurs.

Fifty participants were enrolled from the University of Dundee Medical School and the NHS Tayside Foundation Doctor programme. Participants were assessed for their stereopsis level before completing an orientation module on an ophthalmic surgical simulator. They were then required to repeat a task four times. Automated and objective performance levels were recorded and analysed.

Nineteen (38%) had stereopsis lower than the defined normal of 60 seconds of arc (arcsec). Statistical analysis found no correlation between visual acuity and surgical performance. No statistical difference was found between performance scores and stereoacuities of 30, 60 and 120 arcsec. A statistically significant difference was discovered in the surgical performance of participants with a stereoacuity worse than 120 arcsec (total score = -69.85) as compared to the ones with a stereoacuity of 120 arcsec or better (total score = -42.23) with p = 0.010.

This study provides evidence of a specific level of stereopsis where statistical degradation of surgical performance occurs. The findings of this work may help formulate policy on stereoacuity standards required to commence microsurgical training.