Abstract
Background. According to the literature, diffuse lamellar keratitis (DLK) develops in 4.3–37.5% of cases following excimer laser correction (ELC), with its pathogenesis modulated by the balance between proinflammatory interleukins and growth factors. Aim: to establish the prognostic role of interleukin-8 (IL-8) and transforming growth factor-β2 (TGF-β2) in the development of DLK after ELC using LASIK and Femto-LASIK methods. Materials and methods. 180 patients (360 eyes) with myopia or myopia with myopic astigmatism were operated on. Patients in group 1 (182 eyes) underwent LASIK ELC, patients in group 2 (178 eyes) – Femto-LASIK. All patients were examined 1 week, 1 month, 1.5 and 2.5 years after ELC. In group 1, the number of cases with DLC at all observation periods was 29 (15.9%), in group 2 – 37 (20.8%). The control group included 10 patients from each group who did not develop DLC at any of the observation periods. The content of TGF-β2 and IL-8 in the tear fluid was determined by enzyme-linked immunosorbent assay. Results. In patients without DLC, the content of TGF-β2 and IL-8 in the tear fluid did not change significantly during the observation period. In patients with DLC, TGF-β2 was significantly increased (2.3-3.4 times compared to patients without DLC; p<0.05) at all time points, which was more pronounced when using the Femto-LASIK technique than LASIK. The content of IL-8 in patients with DLC was increased (2.3-3.4 times compared to patients without DLC; p<0.05), but only at early times (after 1 week – 3.1-3.2 times compared to control; p<0.05). The content of IL-8 in the LASIK and Femto-LASIK groups did not differ. After 1 week, but not at other times, a strong correlation between TGF-β2 and IL-8 was noted (r=+0.73; p=0.04). Both markers were associated with the development of DLC (for TGF-β2 r=+0.84, for IL-8 r=+0.60; p<0.001). Calculation of clinical Cut-Off thresholds for DLC development according to the Youden Index established a limit for TGF-β2 – 3237 pg/ml (sensitivity and specificity – 100%). The area under the ROC curve AUC=1.00 (95% CI 1.00-1.00), which indicated a very strong relationship between TGF-β2 content and DLC and the possibility of its use as a biomarker of DLC at all terms. Cut-Off for IL-8 was 4.02 pg/ml, the prognosis had satisfactory characteristics only at early terms. Conclusion. Thus, for the first time in the Ukrainian population, we have established the crucial importance of TGF-β2 accumulation for the development of DLC at different times (from 1 week to 2.5 years) after ELC by LASIK and Femto-LASIK method