title: Early postoperative pain following Epi-LASIK and photorefractive keratectomy: a prospective, comparative, bilateral study.
abstract: OBJECTIVE
  To compare postoperative pain associated with epi-LASIK versus photorefractive keratectomy (PRK).
  
  
  METHODS
  This prospective observer-masked randomized study included 40 eyes of 20 patients with myopia and astigmatism who received epi-LASIK (Moria Epi-K) in one eye and PRK in the contralateral eye. Corneal ablation was done using the NIDEK EC-5000 excimer laser. Patients were seen at days 1, 3, and 6 to rate their pain via three measuring tools: 1) a global subjective rating, 2) a 10-cm visual analog scale, and 3) an 11-point numeric scale of pain.
  
  
  RESULTS
  On postoperative day 1, 19 of 20 patients reported pain in both eyes. Using the global subjective rating scale, patients reported more pain for those eyes treated by PRK. Although clinically relevant, this difference was not statistically significant (P = .56). Based on the 11-point numeric scale of pain and visual analog scale, mean pain scores were similar for both groups. On day 3, using the global subjective rating scale, 11 of 12 patients who had pain reported more in the epi-LASIK treated eye (P = .0005). In addition, epi-LASIK eyes demonstrated higher mean pain scores based on the other two scales (visual analog scale, P = .045 and 11-point numeric scale of pain, P = .023). Only 6 patients reported minimal pain on day 6. It was more frequently reported and slightly more marked in epi-LASIK eyes, but did not reach statistical significance.
  
  
  CONCLUSIONS
  Epi-LASIK and PRK have similar pain on postoperative day 1, but epi-LASIK demonstrated statistically more pain than PRK on days 3 and 6.
authors.affiliation: Cadet Vision Institute, Tijuana, Mexico.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Torres
authors.forename: Cristhian
authors.initials: C
authors.lastname: Sancho
authors.forename: Bryan
authors.initials: B
authors.lastname: Tan
authors.forename: Karina
authors.initials: K
authors.lastname: Padilla
authors.forename: David J
authors.initials: DJ
authors.lastname: Schanzlin
authors.forename: Arturo S
authors.initials: AS
authors.lastname: Chayet
mesh_terms: D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome