A comparative study of the duration and efficacy of tetracaine 1% and bupivacaine 0.75% in controlling pain following photorefractive keratectomy (PRK).

OBJECTIVE: To evaluate if topical bupivacaine 0.75% provides better pain control after excimer laser over topical tetracaine 1% without affecting corneal wound healing, refractive outcome of visual function. DESIGN: A prospective, double-masked trial was conducted in which 38 patients were randomized to receive either tetracaine or bupivacaine every 30 minutes for 24 hours post-operatively. Pain was recorded over a four day period using a Visual Analogue Pain Scale. The rate of epithelial healing was assessed during digitized retro-illumination photography. Visual performance was recorded using best corrected Snellen acuity, objective measurements of haze, halo and glare over a six month period. RESULTS: Tetracaine afforded better pain control (p = 0.05). Full epithelial closure occurred in all patients within 72 hours and no statistically significant difference was recorded in any of the parameters measured. CONCLUSIONS: Contrary to our expectation, the longer acting anaesthetic, bupivacaine, was inferior to tetracaine. Limited and supervised use of topical anaesthetics is recommended in controlling pain following photorefractive keratectomy.