The relationship between the results of cross-linking treatment and inflammatory biomarkers in cases with keratoconus

Objective: To investigate the relationship between the outcomes of corneal cross-linking treatment and inflammatory biomarkers in patients with keratoconus Materials and Methods: 92 eyes of 65 patients who underwent corneal cross-linking were included in this study. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) were calculated from the complete blood count results obtained preoperatively from all patients undergoing corneal cross-linking treatment. For each patient included in the study, corneal tomographies were obtained using Pentacam topography at the preoperative period and at the postoperative final follow-up visit. NLR, PLR, and MPV, as well as changes in sequential measurements obtained from corneal tomography, were statistically analyzed. Results: The mean age of the 65 patients included in the study of whom 27 were female, was 23.77 ± 4.55 years (16–35 years). When the keratoconus (KC) stages of patients who underwent corneal cross-linking (CXL) treatment were evaluated, the mean preoperative stage was 2.24 ± 0.80 (0.50–4.00), and at the final follow-up it was 2.05 ± 0.96 (0.00–3.50). The mean follow-up duration of the study was 16.23 ± 5.04 months (10–27 months). The mean best-corrected visual acuity (BCVA [logMAR]) of the patients was 0.37 ± 0.33 (0.00–1.30) preoperatively, and 0.24 ± 0.24 (0.00–1.00) at the final follow-up. The mean preoperative values of mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were 10.14 ± 0.88 fL (8.10–12.90 fL), 2.27 ± 1.68 (0.73–15.21), and 142.71 ± 127.37 (64.59–1278.57), respectively. In sequential tomographic evaluations, the change in total corneal volume (TDV) was –0.01 ± 2.56 (–7.45 to 13.73), the change in mean keratometry (K_mean) was –0.68 ± 1.47 D (–12.20 to 1.10 D), and the change in pachymetry at the pupil center (KP Center) was –1.24 ± 19.09 μm (–103 to 36 μm). Additionally, the change in thinnest pachymetry (KP Thinnest) was –2.57 ± 18.01 μm (–97 to 36 μm), the change in maximum keratometry (Kmax) was –0.39 ± 3.93 D (–0.9 to –1.1 D), and the change in corneal volume (CV) was 0.69 ± 1.56 mm³ (–1.80 to 10.30 mm³). The change in total corneal densitometry anterior (TCD ANT) was 3.61 ± 5.72 GSU (–7.80 to 38.10 GSU), the change in total corneal densitometry central (TCD CENT) was 0.80 ± 1.42 GSU (–1.42 to 5.50 GSU), the change in total corneal densitometry posterior (TCD POST) was 0.33 ± 1.01 GSU (–3.00 to 2.50 GSU), and the change in total corneal densitometry (TCD) was 1.64 ± 2.38 GSU (–2.40 to 14.30 GSU). Statistical analyses revealed a significant negative correlation between the change in BCVA (logMAR) and both NLR and PLR (p = 0.010 and p = 0.018, respectively). Similarly, a significant negative correlation was observed between the changes in K_mean and Kmax and MPV (p = 0.001 and p <0.001, respectively). Conclusion: Significant correlations were found between inflammatory biomarkers obtained from routine blood tests, namely NLR, PLR, and MPV, and certain corneal tomography parameter changes observed after corneal cross-linking treatment in patients with keratoconus. This finding supports the idea that the degree of inflammation may play a causal role in the outcomes observed after corneal cross-linking treatment. Key words: Keratoconus, inflammatory biomarkers, pentacam,cxl