Histopathological and Clinical-Genetic Analysis of Corneal Specimens in Maroteaux-Lamy Syndrome

Maroteaux-Lamy syndrome (MPSVI) is a rare lysosomal storage disorder caused by an Arylsulfatase B ( ARSB ) deficiency, leading to dermatan sulfate and chondroitin-4-sulfate accumulation. It manifests various systemic clinical features. Enzyme Replacement Therapy with Galsulfase (Naglazyme) manages systemic symptoms, but ocular manifestations, such as corneal opacity, often require surgery. This study examines histopathological features of corneas in patients with MPSVI who underwent penetrating keratoplasty (PK).

A retrospective study of 3 patients with MPSVI included demographics, genetics, clinical history, and ophthalmological findings. Six corneas were analyzed with hematoxylin-eosin and histochemical stains, focusing on structural changes and glycosaminoglycan (GAG) deposition.

All patients, diagnosed between ages 16 months and 11 years, exhibited multisystem involvement. All had corneal clouding because of GAG accumulation, with PK performed between ages 14 and 22. Visual improvement was limited by optic nerve atrophy despite Enzyme Replacement Therapy. Histopathological analysis revealed hydropic-like changes in basal keratinocytes, intracytoplasmic and subepithelial GAG deposits, and thinned Bowman layer disruption. The stroma displayed elongated deposits, whereas Descemet membrane showed thinning without GAG deposits. Endothelium GAG deposits were also identified.

The study highlights the alterations in various corneal layers, which have seldom been reported on Maroteaux-Lamy syndrome. Nonetheless, the GAG deposits identified and the changes in Bowman layer align with the literature. PK temporarily improved corneal clarity. However, long-term visual outcomes were poor because of optic nerve damage. Early diagnosis and multidisciplinary management are essential to improve outcomes.