Systemic therapies for mucopolysaccharidosis: Ocular changes following haematopoietic stem cell transplantation or enzyme replacement therapy - a review

Abstract: The management of mucopolysaccharidosis (MPS) is focused on the multi-organ, sometimes life-threatening, clinical manifestations that occur over time. In the past, the limited, symptom-based treatment options led physicians to adopt a palliative approach towards individual disease-associated complications. The availability of systemic treatments such as haematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) has created a better prognosis for MPS patients, particularly when initiated early in life. As part of an integrated management approach, these therapies could be valuable in managing the ocular features that are present in many children with MPS. HSCT has been shown to stabilize or improve corneal clouding and optic nerve oedema for the majority of patients. Retinal degeneration, in contrast, seems not to be permanently arrested. ERT was more recently introduced and has therefore been less well examined than HSCT; with respect to ocular problems in MPS, the majority of reports indicate stabilization of corneal clouding or visual acuity. However, controversy remains about its effect on other ocular pathologies. Despite the lack of consistent ophthalmic improvement for all patients, both treatment modalities deserve consideration, because even reducing MPS-related eye disease progression is worthwhile.