title: Correlation between TGF-beta1 in tears and corneal haze following LASEK and epi-LASIK.
abstract: OBJECTIVE
  To compare the incidence and degree of corneal haze formation following laser subepithelial keratomileusis (LASEK) and epithelial laser in situ keratomileusis (epi-LASIK), and examine its correlation with tear film transforming growth factor-beta1 (TGF-beta1) levels.
  
  
  METHODS
  This prospective, interventional, clinical trial included 20 eyes (20 patients) randomly assigned to undergo LASEK or epi-LASIK. The level of TGF-beta1 in tear fluid was measured preoperatively and 1, 3, and 5 days postoperatively. Corneal haze was graded at 1 and 3 months after surgery, and the relationship with TGF-beta1 levels was determined.
  
  
  RESULTS
  Mean preoperative spherical equivalent refraction was -4.50 +/- 1.44 diopters (D) (range: -1.50 to -6.00 D) for LASEK eyes and -4.90 +/- 1.26 D (range: -1.75 to -6.00 D) for epi-LASIK eyes. Although mean corneal haze scores at 1 month were significantly higher in LASEK-treated eyes than in epi-LASIK treated eyes (P=.031), these scores were similar at 3 months (P=.608). Tear fluid TGF-beta1 levels were similar in LASEK and epi-LASIK eyes before surgery (P=.458) and significantly higher in the LASEK group at 1, 3, and 5 days postoperatively (P=.015, P=.023, and P=.039, respectively). A positive correlation was noted between tear TGF-beta1 levels on the first postoperative day and the degree of corneal haze at 1 month (r=0.501, P=.016).
  
  
  CONCLUSIONS
  Less corneal haze was noted after epi-LASIK than LASEK. A positive correlation between corneal haze and tear fluid TGF-beta1 levels on the first postoperative day suggest a possible mechanism for the observed difference.
authors.affiliation: Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academic of Medical Science, Medical College, Peking, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Long
authors.forename: Renyuan
authors.initials: R
authors.lastname: Chu
authors.forename: Xingtao
authors.initials: X
authors.lastname: Zhou
authors.forename: Jinhui
authors.initials: J
authors.lastname: Dai
authors.forename: Chongda
authors.initials: C
authors.lastname: Chen
authors.forename: Srinivas K
authors.initials: SK
authors.lastname: Rao
authors.forename: Dennis S C
authors.initials: DS
authors.lastname: Lam
mesh_terms: D000328:Adult; D003318:Corneal Opacity / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D015994:Incidence; D049008:Keratectomy, Subepithelial, Laser-Assisted; D020731:Keratomileusis, Laser In Situ; D008297:Male; D009216:Myopia / Q000601:surgery*; D011183:Postoperative Complications; D011446:Prospective Studies; D013666:Tears / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1
chemical_list: C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1