DIMINISHED SUGAR CATARACTOGENESIS BY QUERCETIN

Aldose reductase was implicated in the pathogenesis of sugar cataracts. Inhibition of the enzyme may delay and possibly prevent cataractogenesis induced by diabetes or galactosemia. In the neonatal rat the fused eyelids provide a natural delivery chamber, an orbital pouch, for the daily deposition of an aldose reductase inhibitor. Topical administration of quercetin, a pentahydroxyflavone, to the orbital pouch of the galactosemic neonatal rat diminishes cataractogenesis in the corresponding lens. Comparison with the contralateral lens indicates that quercetin (1 .times. 10-5 M) reduces intracellular edema, prevents extracellular fluid accumulation and maintains cellular interdigitation of the superficial anterior cortical fiber. Topical application of quercetin preserves fiber integrity and maintains lens growth as seen by radius and dry weight measurements. In normal neonates quercetin (1 .times. 10-5 M) does not alter fiber structure or development. Dietary administration of quercetin to the galactosemic neonates is effective in maintaining individual fiber thickness, density and interdigitations. Many ophthalmic compounds are therapeutically administered in the form of drops or soluble ophthalmic inserts. The neonatal orbital pouch may be a useful model to study the activity and potency of new ophthalmic agents.