Oval lipid corneal opacities in beagles: VI. Quantitation of excess stromal cholesterol and phospholipid.

We identified and quantitated the following lipids in corneas of normolipemic beagles that had oval corneal opacities: total lipids, cholesterol esters, free cholesterol, total phospholipids, phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin and total triacylglycerols. All except the total triacylglycerols were significantly higher in the 20 affected corneas than in ten normal age and sex-matched controls (P less than 0.005 for each). Few long-chain unsaturated fatty acids were detected. This lipid analysis and the previously reported natural history, ultrastructure, and histochemistry indicate that these opacities result from a primary disorder of corneal lipid metabolism that closely resembles central crystalline corneal dystrophy in man.