Corneal Findings in a Patient With Prolidase Deficiency: A Multimodal Imaging Characterization

To provide the first detailed ophthalmologic and multimodal imaging characterization of corneal involvement in a patient with genetically confirmed Prolidase deficiency.

Observational case report.

A 21-year-old man was referred for ophthalmologic evaluation after diagnosis of Prolidase deficiency (homozygous c.825delC, p.Phe275Leufs*46, in PEPD) during investigation for recurrent infections and immune dysregulation. Best-corrected visual acuity was 7/10 in the right eye and counting fingers at 1 m in the left eye. Slit-lamp biomicroscopy demonstrated bilateral, asymmetric corneal disease with diffuse opacification, epithelial and subepithelial fibrosis, anterior stromal haze, and circumferential limbal neovascularization in the left eye, and milder superior corneal involvement in the right eye. Corneal sensitivity was bilaterally reduced. Anterior segment optical coherence tomography revealed diffuse heterogeneous stromal reflectivity, a stromal demarcation line, and superior corneal thinning. In vivo confocal microscopy demonstrated fibrotic epithelial changes, a fragmented subbasal nerve plexus, inflammatory cell infiltration including dendritic cells, fine stromal deposits compatible with imidodipeptide accumulation, and significantly reduced keratocyte density.

:These findings reveal a progressive corneal keratopathy driven by a dual pathomechanism of impaired collagen homeostasis and chronic immune-mediated inflammation, paralleling features of other hereditary collagen disorders. Systematic ophthalmologic surveillance should be incorporated into the routine management of all patients with Prolidase deficiency.