To determine predictable factors of postoperative pain and cut-off values following LASEK eye surgery.

Thirty-three eyes of 17 patients who underwent LASEK from May to December 2008 were reviewed. For evaluation of predictive factors, patients' anxiety level was converted to APAIS, HADS, STAI, and VAS preoperatively. Substance P and prostaglandin E2 levels in tears, blood pressure, heart rate, and history of any previous surgery were determined before the procedure. Thirty minutes and 1 day after LASEK, the subjective degree of pain was scored.

Patients with high Amsterdam preoperative anxiety scale (APAIS) and Visual analogue scale (VAS) scores showed more postoperative pain ( p =0.04, p <0.001). Higher substance P and prostaglandin E2 levels were significantly related with more severe pain after LASEK ( p <0.001, p <0.001). Postoperative pain increased significantly, according to cut-off values ( p <0.05), APAIS and VAS scores greater than 6, substance P greater than 631.84 pg/ml, and prostaglandin E2 greater than 783.90 pg/ml.

The level of pain after LASEK surgery varies individually, and many factors, including physical and psychological variances, can affect the pain. With higher APAIS/VAS scores and higher concentrations of substance P, prostaglandin E2 portends more severe pain following LASEK.