Visual Phenomenon Perceived during Vitrectomy Surgery with MAC Anesthesia

Abstract

 

Purpose

 

To determine the prevalence and preoperative predictors of visual phenomena seen by patients during trans pars plana vitrectomy (TPPV) under monitored anesthesia care (MAC) with local anesthesia. We wished to determine how often patients see visual phenomena, including surgical instruments in the eye, the implications, and the association with different anesthetics.

 

Methods

 

A prospective observational study of 100 TPPV procedures was conducted at a single academic eye hospital on adults under MAC plus peribulbar block between March and October 2013. The pre- and intraoperative intravenous and local anesthetics used were correlated with the results of a postoperative questionnaire administered 1-2 days after surgery. It was designed to elicit patient satisfaction, pain, and presence of the instrument visualization phenomenon. SASS software was used for the Wilcoxon rank sum test and Fisher’s exact test.

 

Results

 

Seventy percent of patients remember being in the operating room, and only 28% of patients reported seeing visual phenomena during the surgery. Of these, 71% of patients saw lights, 50% saw colors, and 17% reported seeing moving instruments. Ten percent of patients who reported seeing visual phenomena found this disconcerting. Seeing moving instruments was not associated with a specific type or combination of intravenous (propofol, fentanyl, midazolam, benadryl) medications, surgical time, preoperative vision, use of gas, or location of intraocular pathology. The average patient reported mild intraoperative discomfort, 3 on a scale of 0 to 10 (maximum pain). The vast majority (95%) were satisfied with the choice of MAC with local over general anesthesia.

 

Conclusions

 

The prevalence of visual phenomena during TPPV is lower than reported by other groups. No association was found with macular pathology, as previously described. In our prospective study designed to investigate visual phenomena, we found few patients disconcerted with visual sensations. MAC with local anesthesia provided excellent analgesia and comfort.

 

 

A drawing entitled “brush” drawn by a highly myopic patient after a macula off retinal detachment repair with silicone oil. Preoperative vision was hand motion, and postoperative vision was 20/800.

 

Keywords: 762 vitreoretinal surgery • 688 retina