Clorazepate dipotassium versus midazolam for premedication in clear corneal cataract surgery

To evaluate and compare the efficacy of oral clorazepate dipotassium (Tranxilium) and intravenous midazolam (Dormicum) as premedication agents in retrobulbar anesthesia and clear corneal phacoemulsification with intraocular lens (IOL) implantation.

Department of Ophthalmology, University of Essen, Essen, Germany.

In a prospective clinical trial, 97 consecutive patients (97 eyes) having phacoemulsification with implantation of a foldable IOL were randomized to 2 groups. The first group received 10 mg oral clorazepate dipotassium and the second group, 1 mg intravenous midazolam. The surgeon's subjective experience of patients' cooperation during retrobulbar anesthesia and after surgery was measured on a 5-point Likert scale. The duration of surgery and rate of complications were documented. One day after surgery, the patients' subjective comfort during cataract surgery was evaluated using a 5-point Likert scale and the best corrected visual acuity was determined.

The level of anterograde amnesia tended to be higher in the midazolam group than in the clorazepate dipotassium group (4% versus 0% for anesthesia administration; 14% versus 4% for surgery), but the difference between groups was not significant. There were no significant differences in patient cooperation or complications during surgery. Patient satisfaction scores were not significantly different between the groups (P<.14); however, patients in the midazolam group expected to have significantly less pain during surgery (P<.04). The rate of potential visual acuity recovery was similar between groups.

Anterograde amnesia occurred more frequently and patients expected less pain before surgery with midazolam. Both anesthetic agents provided safe and effective premedication for retrobulbar anesthesia in clear corneal cataract surgery.