Anterior segment OCT imaging in mucopolysaccharidoses type I, II, and VI

To describe the anterior segment optical coherence tomography (AS-OCT) characteristics of patients with ocular manifestations of mucopolysaccharidoses type I (Hurler), II (Hunter), and VI (Maroteaux-Lamy).

Prospective, observational study of nine consecutive patients with variants of mucopolysaccharidosis (MPS) attending the Paediatric Ophthalmology service at Manchester Royal Eye Hospital, UK. All patients underwent Visante AS-OCT imaging as part of their ophthalmic assessment.

Ocular involvement tended to be symmetrical. Angle-to-angle distance was significantly lower in MPS VI than in MPS I (P=0.04). Anterior chamber depth, angle opening distance, trabecular-iris space area, and scleral spur angle tended to be lower in MPS VI than in MPS I, but did not reach statistical significance. Corneal thickness in the central 0-2 mm zone was greater in MPS VI than in MPS I, approaching but not attaining statistical significance (P=0.07). The 2-5 and 5-7 mm zones were significantly thicker in MPS VI than MPS I (P=0.04, P=0.04). There was no difference in corneal thickness between MPS I and MPS VI in the peripheral 7-10 mm zone (P=0.57). Measurements of the patient with MPS II resembled the mean values of the MPS I group.

AS-OCT is valuable in quantifying anterior segment pathology in MPS. It suggests more crowded anterior segments and greater corneal thickness in patients with MPS VI than MPS I. AS-OCT is useful in evaluating the risk and mechanism of glaucoma in MPS patients, and may improve our assessment of the efficacy of systemic treatment.