title: Pain and Its Determinants in Photorefractive Keratectomy.
abstract: OBJECTIVE
  To assess the determinants of early postoperative pain in photorefractive keratectomy.
  
  
  METHODS
  A prospective cross-sectional study.
  
  
  METHODS
  One hundred and four myopic-astigmatic patients undergoing bilateral standard photorefractive keratectomy were evaluated for early postoperative pain severity. On day 1 postoperatively, the level of pain experienced was reported by the patient on a visual analog scale of 0 to 10. At the preoperative interview, data were collected on clinical, demographic, and social characteristics to find potential pain determinants.
  
  
  RESULTS
  The median reported pain level was 3. About 20% of subjects reported a pain score of 6 or higher, and 2.9% (6 eyes of 4 patients) reported the highest pain score. The presence of external eye inflammatory signs was associated with higher levels of pain (P < 0.001). Patients with a higher body mass index reported more severe pain (P = 0.006). An inverse association was found between pain and harmful lifestyle choices (P = 0.008). Demographic characteristics, history of contact lens wear, history of major operation, past experience of severe pain, knowledge about the operation's adverse effects, preoperative insomnia, preoperative anxiety, operative factors, and refractive indices were not related to the severity of pain experienced (all P > 0.05).
  
  
  CONCLUSIONS
  The association of pain with ocular surface inflammation suggests that inflammatory processes have a role in early postoperative pain, supporting the use of anti-inflammatory agents for pain management. Prescription of weight-adjusted dosages of analgesics is recommended on the basis of the association between severity of postoperative pain and body mass index.
authors.affiliation: From the *Eye Research Center, Farabi Eye Hospital and †Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: S-Farzad
authors.initials: SF
authors.lastname: Mohammadi
authors.forename: Hadi
authors.initials: H
authors.lastname: Z Mehrjardi
authors.forename: Sahar Taba Taba
authors.initials: ST
authors.lastname: Vakili
authors.forename: Mercede
authors.initials: M
authors.lastname: Majdi
authors.forename: Sara
authors.initials: S
authors.lastname: Mirhadi
authors.forename: Firoozeh
authors.initials: F
authors.lastname: Rahimi