Prospective, randomized, contralateral eye comparison of tetracaine and proparacaine for pain control in laser in situ keratomileusis and photorefractive keratectomy

BACKGROUND Tetracaine and proparacaine are two of the most commonly used medications for providing topical anesthesia in laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). These agents have not been previously compared in a prospective manner to determine their efficacy in these settings. METHODS This prospective, single-masked, randomized study comprised 256 eyes from 128 consecutive patients being treated with LASIK or PRK who were randomized to receive tetracaine in one eye and proparacaine in the other. The patients were blinded as to which anesthetic agent was used in each eye. Pain levels were graded on a 0-10 scale, and were assessed upon instillation, during surgery, immediately postoperatively, 30 minutes postoperatively, overnight, and on postoperative day 1. Patients were asked 30 minutes after surgery which anesthetic agent they would choose. RESULTS Both anesthetic agents resulted in diminished amounts of subjective pain in patients undergoing LASIK and PRK. Tetracaine caused significantly more pain upon instillation than proparacaine for both LASIK and PRK patients. LASIK patients noted significantly less pain 30 minutes after surgery when treated with tetracaine. Significantly more LASIK patients preferred the eye treated with tetracaine. These differences were not present in the PRK group. CONCLUSION Both tetracaine and proparacaine are effective methods of topical anesthesia in LASIK and PRK. Tetracaine caused significantly more pain upon instillation in all patients, but resulted in greater analgesia 30 minutes after surgery in the LASIK group. Patients in the LASIK group expressed a preference for tetracaine over proparacaine. There was no significant drop preference among PRK patients.