JAN 09, 2020
Investigators examined factors associated with clinically significant dry eye after keratorefractive surgery.
The authors reviewed 25,317 patients who underwent myopic laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) between 2008 and 2016 at a single center in Israel. Clinically significant dry eye was defined as a dry eye grading of 2 or more at any follow-up visit between 4 weeks and 6 months after surgery.
Postoperative dry eye developed in 1,518 eyes (6%). The dry eye group tended to be older (29.2 vs. 27.6 years, P<0.001), female (48.5% vs. 44.8%; P=0.005) and have lower preoperative spherical equivalent (3.7 vs. 4.0; P<0.001), lower preoperative best-corrected visual acuity (0.019 vs. 0.016 logMAR; P=0.04) and a lower proportion of soft contact lens wearers (40.6% vs. 45.5%; P<0.001).
A higher proportion of patients developed dry eye in the LASIK group compared with the PRK group (52.4% vs. 38.7%; P<0.001). For those with LASIK, a higher percentage were treated with a 7-mm vs. 6-mm optic zone (18.9% vs. 16.3%; P<0.001). In multivariable analysis, older age (OR 1.01), female gender (OR 0.87), lower preoperative refractive error (OR 1.05) and LASIK (OR 0.67) were significantly associated with postoperative dry eye.
The presence of preoperative stage 1 dry eye was allowed if successfully treated prior to surgery. The authors did not disclose the incidence of this diagnosis, which may skew results if those patients were not evenly distributed. There was a difference in rate of dry eye between the 5 surgeons who collectively performed 97% of the surgeries included in this review. These differences could not be attributed to any obvious factors, but the authors presume that it may be due to a difference in diligence of detecting mild preoperative dry eye.
In this large retrospective study, post-refractive surgery dry eye was seen more commonly after LASIK than PRK, especially in those treated with a larger optic zone. Dry eye was more prevalent in patients who are of older age, female gender or with a lower preoperative refractive error.