Objectives: To evaluate predictive factors for corneal scar formation following corneal collagen cross-linking (CXL).Methods: The medical records of 295 progressive keratoconus patients who had undergone accelerated CXL were reviewed retrospectively in this comparative cohort study. Thirty-two eyes of 32 patients who still had a corneal scar in the first year (scar group) and 75 eyes of 75 patients without any scar (control group) were included. The patients' demographic characteristics, preoperative uncorrected distance visual acuity (UCVA) and corrected distance visual acuity (CDVA), slit-lamp biomicroscopy and corneal topographic parameters data were acquired from the patients' files. Multivariable logistic regression analysis and Receiver operating characteristic (ROC) curves were used for the purpose of evaluating predictive factors for corneal scar formation.Results: The UCVA and CDVA, which were determined to be similar between the groups during the preoperative period (P = .63, P = .71, respectively), improved postoperatively in both groups (P = .98, p = .10, respectively). The thinnest point of corneal thickness was statistically lower in the scar group (p = .03). In multivariable logistic regression analysis, preoperative keratometric astigmatism was a predictive value showing postoperative scar development (OR 11.81 95% CI 2.46-56.62, p = .002). Keratometric astigmatism had the highest sensitivity (90%), specificity (86.7%), and accuracy (95%) for scar formation at the best cut-off point of 5.61 D according to the ROC curve.Conclusions: A higher tendency for stromal haze development following CXL was determined in eyes with thinner corneas and higher keratometric astigmatism with the best cut-off value of 5.61 D.
Keywords: Corneal scarring; corneal collagen cross-linking; corneal thickness; keratoconus; keratometric astigmatism.