Aspirin prevents carbamylation of soluble lens proteins and prevents cyanate-induced phase separation opacities in vitro: a possible mechanism by which aspirin could prevent cataract.

The carbamylation of lens proteins by cyanate causes conformational changes, and cyanate causes cataract. There is some evidence that aspirin is beneficial to cataract patients, so its effect on the carbamylation of lens proteins and on opacification produced by cyanate in vitro was studied. Aspirin decreased the phase separation temperature in lenses exposed to cyanate, and was found to reduce the rate of carbamylation of most, if not all, soluble lens proteins. Studies with radiolabelled aspirin lead to the conclusion that the drug achieves this protection by chemically modifying the proteins. The nature of this modification and the relevance of these results to human cataract is discussed.