Clinical, neurophysiological, biochemical and morphological features of eyes in Persian cats with mannosidosis.

The clinical, neurophysiological, morphological and biochemical manifestations of eyes from Persian kittens affected with α-mannosidosis were studied. Clinically the disease is characterized by progressive corneal and lenticular opacification. In addition there is asymmetry in shape and latency of signal conductions which were demonstrated by visual evoked potential studies. Morphological and histochemical studies revealed vacuolization of various ocular cell types which stained positively withConcanavalia ensiformis agglutinin (Con A) and wheat germ agglutinin (WGA). Biochemical studies illustrated low activity of acid α-mannosidase in cultured keratocytes and abnormal storage of partially degraded oligosaccharides in these cells, in vitreous humor and lens. This comprehensive study of ocular α- mannosidosis demonstrates enzyme deficiency which leads to abnormal storage of oligosaccharides in affected cells and is manifested by morphological alterations and functional impairment.