title: [Epidermal growth factor (EGF) in tears in excimer laser photorefractive keratectomy. Responsible for postoperative refraction and "haze"?].
abstract: BACKGROUND
  Corneal wound healing is of critical importance for the postoperative outcome of excimer laser PRK. Wound healing is a complex biological process that is well characterised at the microscopic level, but its regulation is poorly understood at the molecular level. Among various cytokines, epidermal growth factor (EGF) plays an important role in superficial wound healing. The synthesis of EGF varies individually; therefore, by determining the EGF concentration in the tear fluid, patients with increased wound healing activity might be traced.
  
  
  METHODS
  In this study we measured the EGF concentration pre- and postoperatively in the tear fluid of 50 eyes using a ELISA test. The preoperative refraction was between -2.00 and -10.00 dioptres. The maximum follow-up was 6 months.
  
  
  RESULTS
  Preoperatively, in all eyes the EGF concentration in the tear fluid was between 0.2 and 1.7 ng/ml. In contrast, 1 week postoperatively, these values increased (0.21-22.50 ng/ml); 4 weeks postoperatively, the EGF concentration was in all eyes back to preoperative levels. In eyes with high EGF tear fluid concentration 1 week after surgery, refraction at 6 months was outside the intended correction of +/- 1.0 D. We could not find any correlation between EGF concentration and "corneal haze".
  
  
  CONCLUSIONS
  EGF may play an important role in postoperative wound healing after excimer laser PRK. Investigations concerning a pharmaceutical control of EGF should be undertaken.
authors.affiliation: Universitäts-Augenklinik Regensburg.
authors.forename: C P
authors.initials: CP
authors.lastname: Lohmann
authors.forename: E
authors.initials: E
authors.lastname: Hoffmann
authors.forename: U
authors.initials: U
authors.lastname: Reischl
mesh_terms: D000328:Adult; D003318:Corneal Opacity / Q000503:physiopathology*; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications / Q000503:physiopathology*; D012029:Refraction, Ocular; D013666:Tears / Q000378:metabolism*; D014786:Vision Disorders / Q000503:physiopathology*; D014945:Wound Healing / Q000502:physiology
chemical_list: D004815:Epidermal Growth Factor