Ocular complications of Mucopolysaccharidoses

Purpose: To study the extent of ocular involvement among children with mucopolysaccharidoses (MPS) at The Children's Hospital at Westmead, Sydney, Australia. Methods: This study consists of a retrospective consecutive case series, with review of medical records of children with confirmed diagnosis of MPS from 1997 to 2009. Results: Forty-five children had MPS but only 29 had a record of previous formal ocular assessment. Of these, more than half had documented ocular involvement, including corneal clouding, common among the MPS I subtypes and MPS VI (Maroteaux-Lamy) patients. Posterior segment changes, including pigmentary retinopathy, epiretinal membranes and optic disc changes were more common in MPS II (Hunter). Two children with MPS VI were also noted to have epiretinal membranes and this is likely to be a previously unrecognised association of MPS VI. Only 7 out of 18 children with MPS III (Sanfilippo) were examined, and clinically none were found to have retinopathy. Among those who were cooperative for vision assessment, four were found to see 6/12 or better, while the majority had best corrected vision between 6/15 and 6/60. Three patients had documented disease progression leading to blindness. All four MPS VI patients receiving enzyme replacement therapy (ERT) had stable visual acuity with no ocular progression (6.5 years mean follow-up). However progression of corneal clouding was noted in the only MPS I patient receiving ERT. Conclusion: Ocular involvement in MPS may cause significant vision impairment. Formal ophthalmic review is important for early detection and treatment to help achieve the best visual outcome.