A prospective, randomized, double-masked trial to evaluate the role of topical anesthetics in controlling pain after photorefractive keratectomy.

Author(s): Verma S, Corbett MC, Marshall J

Affiliation(s): Department of Ophthalmology, St. Thomas Hospital, London, UK.

Publication date & source: 1995-12, Ophthalmology., 102(12):1918-24.

Publication type: Clinical Trial; Randomized Controlled Trial

PURPOSE: To investigate the role of 1% tetracaine in controlling pain after photo-refractive keratectomy (PRK) and determining its effect, if any, on epithelial healing, refractive outcome, and visual performance. METHODS: In this study, 44 patients were randomized to receive either Gutt. 1% tetracaine or placebo after undergoing PRK. Drops were instilled at 30-minute intervals during waking hours for 24 hours postoperatively. In addition, all patients received two coproxamol (paracetamol + dextropropoxyphene) tablets every 6 hours for 2 days. Visual Analogue Pain Charts were used to record pain levels for 4 days after surgery. Serial digitized retro-illumination photography was used to assess rates of epithelial healing, and surface epithelial quality was monitored using topography. At fixed intervals over a 6-month period visual performance was assessed by measuring refractive outcome, best-corrected visual acuity, objective haze, halo, and glare. RESULTS: Patients in the tetracaine group had significantly less pain (P < 0.0001). Both groups demonstrated full epithelial closure within 72 hours. Similar numbers of patients in both groups at 1 week showed topographic irregularity that completely resolved by 1 month. No statistically significant difference was seen in any of the parameters monitoring visual performance. CONCLUSIONS: Tetracaine in conjunction with coproxamol is effective in reducing pain after PRK without adversely affecting corneal wound healing or visual performance.