Effect of a hyperosmotic agent on epithelial disruptions during laser in situ keratomileusis

To evaluate the incidence of epithelial disruptions during primary laser in situ keratomileusis (LASIK) with the use of a preoperative hyperosmotic treatment comprising sodium chloride 5% ophthalmic ointment (Muro-128) and to identify the incidence of epithelial disruptions in various demographic populations.

TLC Laser Eye Center, McLean, Virginia, USA.

Comparative case series.

Using a matched-pair design, hyperosmotic treatment was randomized to 1 eye of patients having bilateral LASIK. The primary outcome measure, epithelial integrity, was assessed in each eye. Epithelial integrity was evaluated in groups defined by characteristics that included age, sex, ethnicity, skin type, presence or absence of rosacea, eye color, and hair color.

The study evaluated 496 eyes of 248 patients. The preoperative hyperosmotic treatment was associated with significantly less corneal epithelial disruption, as indicated by an epithelial integrity score. Compared with control eyes, the rate of corneal epithelial disruptions in the population of treated eyes decreased by 40% (relative risk, 0.60; 95% confidence interval [CI], 0.38-0.95). Among the characteristics studied, age was the best predictor of corneal epithelial disruptions; every 1-year increase in age was associated with a 9.0% increase in the risk for corneal epithelial disruptions (odds ratio [OR], 1.09; 95% CI, 1.05-1.13). Eyes of patients older than 34 years had a 4.4 times greater odds of being associated with epithelial disturbances than eyes of patients 34 years or younger.

The preoperative use of hyperosmotic agents can reduce the risk for intraoperative epithelial disruptions during LASIK. An increase in epithelial disruptions was associated with increasing age.