In vivo corneal confocal microscopy findings in cases with pterygium: a case-control study

This study aimed to evaluate corneal findings of pterygium cases using in vivo confocal microscopy (IVCM) which is a non-invasive and repeatable method. In this case-control study, 54 patients diagnosed with pterygium and 50 healthy controls were investigated, between 2020 and 2021. After a comprehensive ophthalmological examination, the central corneas of all participants were evaluated by corneal IVCM. Surface epithelial cell, wing cells, basal epithelial cells, nerve fiber density, nerve branch density, anterior and posterior stroma keratocyte densities were measured. Corneas from cases with and without pterygium were similar in terms of age (p = 0.306) and gender (p = 0.564). No statistically significant differences were found in the epithelium cell counts including surface, wing, and basal cells between the two groups (p = 0.950, p = 0.334, and p = 0.624, respectively). No statistically significant differences were observed in subepithelial nerve fiber density (p = 0.849), nerve branch density (p = 0.752), and posterior stromal keratocyte density (p = 0.683) between corneas from cases with and without pterygium. However, corneas from cases with pterygium had significantly higher scores in anterior stromal keratocyte density than those from cases without pterygium (p = 0.045). Corneas from grades 1, 2, and 3 pterygium were similar in cell counts, anterior and posterior stromal keratocyte densities (p > 0.05). However, patients with grade 1 had significantly increased nerve fiber density (p = 0.015) and nerve branch density (p = 0.001) than those with grade 2 and grade 3 pterygium. Corneal IVCM may be useful to better understand the corneal microstructure in cases with pterygium. Comprehensive research on the subject is needed.