Morphological changes in vernal keratoconjunctivitis over time: A confocal imaging perspective

To compare and analyze corneal confocal changes in patients with vernal keratoconjunctivitis (VKC) based on the disease duration.

A prospective cross-sectional hospital-based analysis of patients with VKC who underwent laser scanning confocal microscopy of the central cornea. Based on disease duration, patients were categorized as Group A (<5 years) and Group B (>5 years) irrespective of their disease activity. ACC Metrics was used for nerve fiber layer analysis, while Image J was used to evaluate the superficial epithelium and anterior stromal keratocytes.

Confocal microscopy was performed on 38 eyes of 21 patients, with 22 eyes in Group A and 16 in Group B. Both groups had a comparable distribution of active versus inactive cases and mild versus severe grades. Group B demonstrated a significant increase in superficial epithelial cell length and inflammatory cell density. Additionally, Group B exhibited significantly thinner sub-basal nerves, along with increased stromal nerve thickness, branching, and deflection compared to Group A. No significant differences were observed in sub-basal nerve density or length, or in keratocyte density and area. Although an increase in activated keratocytes was noted in Group B, it did not reach statistical significance.

Corneal confocal microscopy reveals distinct morphological changes in VKC based on disease duration, suggesting that chronicity may contribute to progressive neuroinflammatory alteration in the cornea.