Correlation between sub-Tenon's anesthesia and transient amaurosis during ophthalmic surgery.

PURPOSE: To verify the correlation between sub-Tenon's anesthesia and intraoperative visual loss in ophthalmic surgery. METHODS: Sixty-four patients underwent phacoemulsification combined pars plana vitrectomy under sub-Tenon's anesthesia. Participants were investigated about their light perception at several time points: before anesthesia, immediately after anesthesia, 10 min after anesthesia without any surgical intervention or microscope illumination, and after the whole surgery. Intraoperative amaurosis was determined as that a patient could not see any light from their operative eye. The incidence rate of amaurosis at different time points and among different anesthetists was analyzed. RESULTS: The rate of intraoperative amaurosis was 0%, 1.56%, 48.44%, and 95.31% at several time points, respectively: before anesthesia, immediately after anesthesia, 10 min after anesthesia without any surgical intervention or microscope light exposure during the interval, and immediately after the whole surgery, presenting a significantly time-dependent increase (P < 0.01). There was no correlation between the amaurosis and different diseases and anesthesiologists. The amaurosis was transient, and all operative eyes could perceive light on the first postoperative day. CONCLUSIONS: Sub-Tenon's anesthesia contributes to the intraoperative amaurosis during operation. Temporary interruption of optic nerve conduction by the anesthetic could be a credible explanation. The amaurosis is transient and reversible, requires no additional treatment, and should not be considered as a surgical complication.