Pain After Epithelial Removal by Ethanol-assisted Mechanical Versus Transepithelial Excimer Laser Debridement

Abstract

PURPOSE: To compare subjective pain responses between two techniques of epithelial removal prior to photorefractive keratectomy (PRK) treatment: ethanol-soaked pledget with mechanical debridement of the epithelium versus excimer laser transepithelial ablation. METHODS: Nine patients underwent bilateral PRK. Each had the epithelium in one eye debrided by placing a pledget soaked in 20% ethanol on the cornea for 2 minutes followed by gentle scraping with a blade. The epithelium in the other eye was removed by transepithelial phototherapeutic keratectomy (PTK) treatment. For each eye, PRK was initiated immediately after removal of the epithelium. On postoperative day one, each patient was asked to rate the level of pain suffered over the last 24 hours on a scale of 0 (minimal) to 10 (maximal). Data were analyzed in a masked fashion. RESULTS: Postoperative day one average pain level in the ethanol-assisted mechanically debrided eyes was 3.0 ± 2.5 and in the transepithelial PTK eyes was 6.8 ± 1.8. The difference was statistically significant by Student's ¿-test (P < .01). All epithelial defects healed within 3 days with no clinically significant difference in healing time between the two techniques. CONCLUSION: In preparation for PRK, ethanolassisted mechanical debridement of the epithelium caused significantly less postoperative pain than epithelial removal using the excimer laser. [J Refract Surg 2000;16:519-522]

Pain, wound healing and refractive comparison of mechanical and transepithelial debridement in photorefractive keratectomy for myopia: Results of 1 year follow-up

“…In the t-PRK group, for all measurements at postoperative days 1 and 3, the scores were lower than in the mechanical PRK group. However Kanitkar et al [52] found that pain after epithelial removal by the ethanol-assisted mechanical technique was lower than transepithelial excimer LASER debridement.…”

“…The idea of considering t-PRK as a main treatment option was proposed in 1998 [35]. However, the idea was not proven until 2007 [36,37]. In 2007, t-PRK treatment provided better results than LASIK, LASEK, and epi-LASIK surgeries, phototherapeutic keratectomy mode for epithelial debridement and stromal ablation mode were used for the treatment [38].…”

Transepithelial photorefractive keratectomy: Clinical results

“…At all postoperative intervals, mechanical removal of the epithelium tended to yield better results than laser epithelium removal. In 2000, Kanitkar et al 16 reported 9 patients who had bilateral PRK using the Visx S3 laser, with 1 eye deepithelialized with PTK and the fellow eye deepithelialized with alcohol. All eyes healed within 3 days with no difference in healing time between the 2 groups.…”

Comparison of single-step reverse transepithelial all-surface laser ablation (ASLA) to alcohol-assisted photorefractive keratectomy

“…The use of alcohol as an alternative to mechanical debridement has been assessed, as has preservation of the epithelium as a flap (laser-assisted sub-epithelial keratectomy [LASEK] and Epi-LASIK) 4. Another alternative is transepithelial PRK, where epithelial removal is generally carried out with laser phototherapeutic (PTK) ablation, followed by a stromal laser refractive ablation 5–8. Transepithelial PRK has several advantages, including no instrument contact with the eye, reduced intervention time, and the potential to minimize the size of an epithelial defect to that required for stromal ablation, as well as the avoidance of alcohol and, thus, potential toxicity.…”