John Stolz, Sergei Astakhov, Alla Lisochkina, Yuri Astakhov

Laser-assisted in situ keratomileusis (LASIK) is commonly used to correct refractive defects. The procedure frequently results in dry eye symptoms, usually of short but sometimes longer duration. This study was designed to assess dry eye and ocular tolerability after LASIK in patients treated with a preservative-free lacrimal substitute (Hylabak®) or preserved lacrimal substitute (Systane®). In a single-center, investigator-masked, prospective, noninferiority, clinical study, patients undergoing LASIK surgery were randomized to receive Hylabak or Systane eye drops (one drop in each eye four times daily for 3 months). Fluorescein test scores were the primary efficacy variable and were similar on day 1 (mean 0.26 and 0.28 for Hylabak and Systane, respectively). At the final visit (day 84 ± 3) the fluorescein scores had improved to 0.11 and 0.04, respectively. The difference was not significant and thus noninferiority was established. A trend of more rapid improvement in the Hylabak group was evident. Both treatments were well tolerated and there were no serious adverse events, discontinuations for adverse events or other safety-related reasons, and no systemic adverse events. The results suggest that Hylabak is not less effective than Systane in reducing the symptoms of dry eye after LASIK surgery.