Correlation Between TGF-β1 in Tears and Corneal Haze Following LASEK and Epi-LASIK

PURPOSE: 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-β1 (TGF-pl) levels. METHODS: This prospective, interventional, clinical trial included 20 eyes (20 patients) randomly assigned to undergo LASEK or epi-LASIK. The level of TGF-pl 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-pl 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-pl 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-β1 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 epiLASIK than LASEK. A positive correlation between corneal haze and tear fluid TGF-pl levels on the first postoperative day suggest a possible mechanism for the observed difference.