title: Postoperative pain after corneal collagen cross-linking.
abstract: OBJECTIVE
  To evaluate the postoperative pain after corneal collagen cross-linking (CXL).
  
  
  METHODS
  : This prospective study included 178 consecutive eyes of 135 patients with progressive keratoconus who underwent CXL at Sadalla Amin Ghanem Eye Hospital, Joinville, Brazil. Pain was assessed postoperatively using the need for analgesia with 30 mg of codeine (Tylex) and by the patients' subjective evaluation on the Wong-Baker FACES Pain Rating Scale at the end of each day until postoperative day (PO) 5. Correlation of postoperative pain with maximum keratometric reading and central corneal thickness, which were assessed preoperatively, was investigated.
  
  
  RESULTS
  Mean patient age was 23.38 ± 5.86 years. Mean (±SD) patient-scored pain decreased significantly (P < 0.05) from 2.78 (±1.68) on the day of surgery (immediate postoperative period, iPO) to 0.12 (±0.46) on PO5. The mean number of codeine pills was 0.94, 0.72, and 0.28 at iPO, PO1, and PO2, respectively, showing a significant decrease at each time point. Statistical analysis showed significant (P < 0.05) correlation between age and pain at PO3 and PO4 (the younger the patients the greater the pain) and between age and the number of codeine pills on iPO. There was no significant correlation between mean overall pain and preoperative apical keratometry (P = 0.546) and pachymetry (P = 0.072) readings.
  
  
  CONCLUSIONS
  CXL postoperative pain can be intense, especially in the first 3 days, even with an aggressive pain control regimen; however, pain and the need for analgesia decreased significantly on each consecutive day. Pain was significantly correlated with the patient's age.
authors.affiliation: Cornea Department, Sadalla Amin Ghanem Eye Hospital, Joinville, Brazil. vcghanem@hotmail.com
authors.forename: Vinícius C
authors.initials: VC
authors.lastname: Ghanem
authors.forename: Ramon C
authors.initials: RC
authors.lastname: Ghanem
authors.forename: Renan
authors.initials: R
authors.lastname: de Oliveira
mesh_terms: D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D003061:Codeine / Q000627:therapeutic use; D003094:Collagen / Q000378:metabolism*; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D058447:Eye Pain / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D011795:Surveys and Questionnaires; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin; D003061:Codeine