Ocular ultrastructural studies of two cases of the Hurler syndrome (systemic mucopolysaccharidosis I-H)

Abstract

The ocular histopathology of Hurler syndrome (systemic mucopolysaccharidosis, type I-H), with emphasis on ultrastructural findings is reported in two cases. Numerous fine fibrillogranular inclusions were observed in: conjunctival fibrocytes; corneal epithelium, keratocytes and endothelium; uveal melanocytes and fibrocytes; ciliary epithelium; smooth muscle cells of ciliary body; pericytes; lens epithelium; retinal pigment epithelium; ganglion cells; and sclerocytes. Some multimembranous inclusions were noted in Schwann cells, keratocytes, trabecular endothelium, uveal fibrocytes and melanocytes, retinal ganglion cells, sclerocytes, optic nerve astrocytes, and vascular pericytes. Extracellular fibrillogranular material was present in the corneal stroma, Descemet's membrane, and scleral stroma. The extensive involvement of the ocular tissues of these two cases emphasizes Hurler syndrome as the most severe form of the systemic mucopolysaccharidoses.

Key Words:

• autophagocytosis
• electron microscopy
• fibrillogranular material
• histochemistry
• Hurler syndrome
• inclusions
• membranous inclusions
• MPS I-H
• systemic mucopolysaccharidosis