Corneal Sensitivity and Patient-Reported Dry Eye Symptoms in a Prospective Randomized Contralateral-Eye Trial Comparing Laser In Situ Keratomileusis and Small Incision Lenticule Extraction

To prospectively compare corneal sensation and patient-reported symptoms of dry eye in individuals undergoing laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE).Prospective randomized contralateral-eye clinical trial.80 eyes of 40 patients with myopia at Byers Eye Institute at Stanford University were randomized to receive wavefront-guided femtosecond LASIK in one eye and SMILE in the fellow eye. Cochet-Bonnet esthesiometry was performed to assess corneal sensitivity preoperatively and at the 1-, 3-, 6-, and 12-month postoperative visits. Participants also completed questionnaires at each visit to determine the Ocular Surface Disease Index (OSDI).Eyes that underwent LASIK compared to SMILE demonstrated more corneal denervation at the postoperative 1-month (mean 2.1 vs 3.6 cm, P < .001), 3-month (3.5 vs 5.4 cm, P < .001), and 6-month (4.7 vs 5.7 cm, P < .001) visits. At the 12-month visit, both groups had returned to baseline corneal sensitivity (5.9 vs 5.9 cm, P = .908). There was no difference in OSDI between the 2 groups at any visit. Mean OSDI improved from the preoperative to the postoperative 12-month visit in both LASIK (15.3 to 8.6, P = .020) and SMILE (15.1 to 9.5, P = .029) groups.LASIK resulted in greater corneal denervation compared to SMILE in the early postoperative period, though this difference was no longer apparent after 12 months. Despite this, there was no difference in self-reported dry eye symptoms between the 2 groups. Patient-reported dry eye symptoms improved after both LASIK and SMILE procedures.