[Changes in sulfated proteoglycans in alkali injured rabbit cornea]

Morphological changes of sulfated proteoglycans (S-PGs) in the stroma of alkali injured rabbit corneas were examined electron-histochemically following cuprolinic blue (CB) dye binding. The injured eyes were followed for 2 months by slitlamp microscope and photographs. At 1 hour, 3 days, 1 week, 2 weeks, 1 month, and 2 months after the injury, the eyes were enucleated and studied. After 1 hour, while both collagen fibrils and the filaments of S-PGs had already become disarranged; the number of S-PGs appeared to decrease. From 3 days to 1 week after, the number as well as the electron-density of S-PGs were markedly decreased in all areas. After 2 weeks, CB-positive large filaments appeared in anterior stroma. These became larger, more abnormal in shape, and displayed a higher electron density 1 month later. Normally arranged S-PGs can be seen at 2 months later. It was concluded that S-PGs were diminished in alkali-injured corneas. Once they were replaced by abnormal filaments, they gradually recovered normal morphology. Further more the time course of S-PG change correlated with that of corneal transparency after alkali injury.