The structure and function of basement membrane (lens capsule) in relation to diabetes and cataract.

The water permeability of the basement membrane (lens capsule) of the crystalline lens of the adult normal and diabetic rat has been investigated. The hydraulic conductivity at low pressure is 51.4 +/- 7.8 X 10(-12) msec-1 Pa-1 in the normal rats and 70.3 +/- 11.1 msec-1 Pa-1 in the diabetic rat. A 37 per cent increase in hydraulic permeability of diabetic membrane was correlated with slit lamp and electron microscopic appearances of oedematous lens fibres in an adult human diabetic lens and the rabbit lens in which the posterior lens capsule had been perforated.