Objective:
To examine the effects of topical 3-isobutyl-1-methylxanthine treatment on tear-film osmolarity, conjunctival goblet-cell densities, and corneal epithelial glycogen levels in a rabbit model for keratoconjunctivitis sicca.
Methods:
Keratoconjunctivitis sicca was surgically induced in the right eyes of 16 rabbits. In a masked protocol, eight of these operated-on eyes underwent treatment for 12 weeks with a 3.0-mmol solution of 3-isobutyl-1-methylxanthine. The remaining eight operated-on eyes were left untreated and served as controls.
Results:
The 3-isobutyl-1-methylxanthine treatment resulted in a rapid and significant decrease in tear osmolarity and sodium (P<.5) and potassium levels (P<.05) and a significant increase in conjunctival goblet-cell densities and corneal epithelial glycogen levels compared with untreated and operated-on controls (P<.001).
Conclusions:
3-Isobutyl-1-methylxanthine rapidly and significantly decreased tear-film osmolarity in this rabbit model for keratoconjunctivitis sicca and restored conjunctival goblet-cell densities and corneal glycogen levels, thus reversing the disease process.