Difference in Swelling and Opacity Formation between Young and Old Lenses

Abstract

THE present theory of cataract formation in young galactose-fed animals and in young diabetic animals suggests that accumulation of dulcitol or sorbitol in the lens causes it to swell and that this swelling leads to metabolic upset and opacity formation^1,2. Patterson and Bunting³, however, have suggested that another metabolite, the nature of which is still unknown, contributes to swelling and opacity formation in the young lens of the galactose-fed rat. This idea is based on their finding that swelling is greater and opacity formation both quicker and more complete in the young rat lens than in the mature rat lens, although dulcitol accumulation is the same in both. It is true that the presence of another metabolite of galactose, besides dulcitol, could explain these observations, but it is also possible that differences between young and mature lenses could be caused by a physical difference in the elasticity of the lens capsule and fibre membranes rather than to any chemical difference.