Subclinical chronic corneal remodeling and Bowman’s layer thickening in X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a rare primary immunodeficiency caused by loss-of-function variants in the BTK gene, resulting in profound humoral immune deficiency. Despite well-characterized systemic manifestations, the structural consequences of ocular surface involvement in XLA remain poorly defined. We report a case of progressive corneal remodeling and Bowman’s layer (BL) abnormalities in a pediatric XLA patient, characterized through multimodal imaging. A 12-year-old male with a confirmed BTK pathogenic variant and established XLA, maintained on regular intravenous immunoglobulin (IVIG) therapy, presented with an 18-month history of bilateral blurred vision and recurrent conjunctival injection. Slit-lamp examination revealed bilateral grayish-white stromal opacities with irregular scarring. Anterior segment optical coherence tomography (AS-OCT) demonstrated diffuse hyperreflective BL thickening with an irregular anterior contour and a minimum corneal thickness of 260 μm in the left eye. In vivo confocal microscopy (IVCM) revealed epithelial cells with hyperreflective nuclei, subepithelial cells morphologically consistent with activated Langerhans cells, amorphous hyperreflective deposits, and tubular structures potentially representing vascular channels within the BL region. Anterior stromal keratocytes exhibited an enlarged stellate morphology potentially indicative of a reactive phenotype. These findings suggest that XLA may be associated with chronic, subclinical corneal inflammatory remodeling. A presumed deficiency of secretory IgA may potentially disrupt ocular surface homeostasis, possibly contributing to aberrant extracellular matrix deposition in the BL. Multimodal imaging may be valuable for detecting clinically occult structural compromise in XLA patients whose corneal status could be underestimated on routine examination.