To investigate changes in intraocular pressure (IOP) after corneal refractive surgery and determine risk factors associated with increased IOP (IIOP).

This retrospective observational study was comprised of 450 eyes of 225 patients, each of whom had corneal refractive surgery in Seoul National University Hospital between January 2004 and January 2008, and were followed for more than one month. IIOP was defined as IOP above 130% of the predicted IOP, adjusted according to corneal thickness and repeated more than twice after postoperative 1 week or after anti-glaucoma medication was needed. Correlation and stratified regression analyses were performed for eyes with myopia and IIOP. Logistic regression analysis was performed to assess risk factors of IIOP and need for medication.

IIOP was detected in 22.2%, and anti-glaucoma medication was required in 12.0%, of eyes. The mean IIOP of the medication group was 5.6 ± 3.4 mmHg. Stratified regression analysis showed that the proportion of IIOP did not differ significantly by the degree of myopia. Logistic regression analysis revealed that statistically significant risk factors of IIOP were female gender, preoperative low IOP, and thicker cornea. The statistically significant risk factor of need for medication was the corneal thickness.

Thick corneal thickness was found to be a significant risk factor of IIOP after corneal refractive surgery was performed, and IIOP was not affected by the degree of myopia.