Effect of midazolam on anxiety level and pain perception in cataract surgery with topical anesthesia

To study the effect of sedation on patients' anxiety level and perception of pain during cataract surgery under topical anesthesia.

Royal Eye Infirmary, Plymouth, England.

This prospective controlled double-blind clinical trial comprised 100 consecutive patients having routine phacoemulsification with posterior chamber intraocular lens implantation under topical anesthesia by a single experienced surgeon. Patients were randomized to receive intravenous midazolam (0.015 mg/kg body weight) 15 minutes before surgery or no sedation. The main evaluation criteria were the anxiety based on the 6-item, short form of the State-Trait Anxiety Inventory, the pain score using a visual analog scale, and overall patient satisfaction.

All operations were uneventful, and no side effects were noted from the use of midazolam. Anxiety scores were significantly higher on arrival at the hospital than just before the commencement and after the conclusion of the surgery in both groups (P<.05). Patients were less anxious after administration of midazolam, but this did not achieve statistical significance. The mean pain score was 0.29 (range 0 to 4) in the sedation group and 0.38 (range 0 to 4) in the control group; the difference between groups was not statistically significant. The patients were equally satisfied in both groups, with mean scores of 3.84 (range 0 to 4) and 3.88 (range 2 to 4), respectively.

Patients who had cataract surgery under topical anesthesia were highly satisfied with their operative experience and reported minimal pain during surgery. Anxiety levels diminished after arrival at the hospital, possibly because of reassurance by experienced staff. Intravenous midazolam did not seem to significantly reduce pain or anxiety.