Clinical Review on Mucopolysaccharidosis and its Ocular Significance

Abstract

A condition with deficiency of various enzymes which plays a crucial role in the degradation of glycosaminoglycans (GAG) is termed to be mucopolysaccharidosis (MPS). The disease entity is due to abnormal breakdown and diffuse accumulation of GAG in the various system including brain, eye, muscle, lungs, heart, and gastrointestinal system. The disease spectrum is highly varied from slight phenotypic changes to severe life-threatening illness. Morbidity, especially low visual acuity is due to the involvement of cornea (clouding of the cornea), optic nerve abnormality, and also retinopathy. Marked impairment of physical and intellectual function is common. The diagnosis is mostly clinical and advanced testing including enzyme assay and gene testing is required for typing and pinpoint diagnosis. The treatment options are limited in most cases as enzyme replacement therapy is not widely available and expensive. Bone marrow transplantation has been found to be successful but still a cumbersome option. Visual morbidity can be reduced by performing keratoplasty if corneal clouding is significant and visual prognosis is often guarded.