title: Photorefractive keratectomy with mitomycin C after penetrating and lamellar keratoplasty.
abstract: OBJECTIVE
  To assess the safety and efficacy of photorefractive keratectomy with mitomycin C (PRK-MMC) to correct refractive errors after corneal transplantation.
  
  
  METHODS
  This was a prospective and noncomparative study of 36 eyes that underwent PRK-MMC after penetrating (n = 34) or lamellar (n = 2) keratoplasty. After mechanical epithelial removal and photoablation, a sponge with mitomycin C 0.02% was applied to the stromal bed for 1 minute. The uncorrected and best-corrected visual acuities, refraction, and complications were assessed.
  
  
  RESULTS
  The average follow-up was 16.27 ± 8.38 months (range, 6-30.5 months). The spherical equivalent decreased from -3.95 ± 4.11 to -1.07 ± 1.45 diopters (D) postoperatively (P < 0.001). The mean preoperative astigmatism was 4.42 ± 1.69 D (range, 1.00-7.25 D); however, surgical correction was limited to 6.00 D. Vector analysis of astigmatic correction showed an index of success of 55%. At the last follow-up, 41.7% (n = 15) and 61.1% (n = 22) of the eyes were within ±0.50 and ±1.00 D of emmetropia, respectively. Nineteen eyes (52.8%) achieved an uncorrected visual acuity of 20/40 or better. The best-corrected visual acuity remained within 1 line of the preoperative values in 26 cases (72.2%), improved in 8 (22.2%), and decreased in 2 (5.6%). Endothelial cell decompensation was observed in 1 eye (2.8%) 11 months postoperatively, and haze developed in 3 cases (8.3%).
  
  
  CONCLUSIONS
  PRK-MMC may be an option to correct refractive errors after keratoplasty. A low preoperative endothelial cell count and haze may affect the safety outcomes.
authors.affiliation: Eye Clinic Day Hospital, São Paulo, Brazil. forseto@uol.com.br
authors.forename: Adriana dos Santos
authors.initials: Ados S
authors.lastname: Forseto
authors.forename: Junia Cabral
authors.initials: JC
authors.lastname: Marques
authors.forename: Walton
authors.initials: W
authors.lastname: Nosé
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D016039:Corneal Transplantation; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D015948:Keratoplasty, Penetrating; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage*; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D016685:Mitomycin