Risk Factors for Dry Eye After Refractive Surgery

Purpose: To determine the factors associated with clinically significant dry eye after keratorefractive surgery. Methods: This is a large database retrospective study that included consecutive cases of myopic laser in situ keratomileusis (LASIK) or photorefractive keratectomy performed between 2008 and 2016 at Care-Vision Laser Center, Israel. Patients were divided into 2 groups according to whether they developed clinically significant dry eye. Results: A total of 25,317 right eyes of 25,317 patients, with a mean age of 27.0 ± 8.3 years, were included. Postoperative dry eye developed in 1518 eyes (6.0%). The dry eye group was older (29.2 ± 9.0 vs. 27.6 ± 8.3 yrs, P < 0.001) and had a higher proportion of women (48.5% vs. 44.8%, P = 0.005), lower preoperative spherical equivalent (3.7 ± 2.0 vs. 4.0 ± 2.3D, P < 0.001), lower preoperative best-corrected visual acuity (0.019 ± 0.057 vs. 0.016 ± 0.064 Logarithm of the Minimum Angle of Resolution (LogMAR), P = 0.04), and lower proportion of preoperative soft contact lens wearers (40.6% vs. 45.5%, P < 0.001). In the postoperative dry eye group, a high proportion underwent LASIK (52.4% vs. 38.7%, P < 0.001) and were treated with a 7.0-mm (as opposed to 6.0 mm) optic zone (18.9% vs. 16.3%, P < 0.001). In multivariable analysis, older age [odds ratio (OR) 1.013, P < 0.001], female gender (OR 0.87, P = 0.009), lower preoperative refractive error (OR 1.05, P < 0.001), and LASIK (OR 0.67, P < 0.001) were associated with postoperative dry eye. Conclusions: Patients who are of older age, are of female gender, and have a lower preoperative refractive error and those undergoing LASIK are more likely to develop dry eye disease after keratorefractive surgery.