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

Area of Science:

• Ophthalmology
• Genetics
• Corneal Disease

Background:

• Prolidase deficiency (PD) is a rare autosomal recessive disorder.
• It results from mutations in the PEPD gene, leading to imidodipeptidase deficiency.
• PD is associated with recurrent infections, immune dysregulation, and characteristic skin and facial findings.

Purpose of the Study:

• To present the first comprehensive ophthalmologic and multimodal imaging characterization of corneal involvement in a patient with genetically confirmed Prolidase deficiency.
• To elucidate the pathomechanisms underlying corneal disease in PD.

Main Methods:

• Observational case report of a 21-year-old male with genetically confirmed Prolidase deficiency.
• Ophthalmologic examination including best-corrected visual acuity, slit-lamp biomicroscopy, and corneal sensitivity testing.
• Multimodal imaging: anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM).

Main Results:

• Bilateral, asymmetric corneal disease observed, with severe opacification, fibrosis, stromal haze, and neovascularization in the left eye.
• Reduced corneal sensitivity, stromal thinning, and heterogeneous stromal reflectivity on AS-OCT.
• IVCM showed fibrotic epithelial changes, fragmented nerves, inflammatory cells, stromal deposits (imidodipeptide accumulation), and reduced keratocyte density.

Conclusions:

• Prolidase deficiency causes a progressive corneal keratopathy.
• The disease is driven by impaired collagen homeostasis and chronic immune-mediated inflammation.
• Routine ophthalmologic surveillance is recommended for all patients with Prolidase deficiency.