This study compared self-reported symptoms of dry eye, visual fluctuations, and foreign body sensation after LASIK and PRK. The authors found that both procedures caused an increase in these factors over baseline in the early postoperative period, with greater vision fluctuations after PRK. However, by one year after surgery, all symptoms of dry eye, vision fluctuations, and foreign body sensation had returned to preoperative levels.
The study included 34 patients (68 eyes). One eye of each patient was treated with wavefront-guided LASIK and the contralateral eye with wavefront-guided PRK. LASIK flap-creation was performed with a 60-kHz IntraLase (Advanced Medical Optics, Inc, Santa Ana, CA) femtosecond laser, creating a superiorly-hinged flap. Eyes were randomized into LASIK versus PRK based on ocular dominance, with equal numbers of dominant eyes in each group.
Patients completed questionnaires about eye dryness, vision fluctuations and foreign body sensation preoperatively and one, three, six and 12 months postoperatively.
There was a significant increase in symptoms and severity of dry eye in both groups of eyes compared to baseline at one month but not at any of the remaining time points. Also there was no difference in dry eye symptoms and severity between the groups at any time point.
There was a significant increase in frequency of visual fluctuations reported at one, three, and six months compared to baseline, but not at 12 months. At one month, there was a significantly higher rate of visual fluctuations reported in PRK eyes compared with LASIK eyes (P = 0.003), but not at any other point.
At one month, there was a mild increase in foreign body sensation in both LASIK- (P = 0.06) and PRK-treated eyes (P = 0.37), neither of which reached statistical significance. There were no differences between the groups in foreign body sensation at any time point.
This study is unique because it is prospective and randomized, although it is limited by its small sample size and lack of objective examination findings to corroborate dry eye symptoms. Generally, the results agree with other reports and clinical results seen with present-day excimer laser refractive procedures.