Mesopic vision after LASIK for myopia

Background: Data on mesopic vision after LASIK are not available to date. We therefore evaluated mesopic vision in myopic eyes before and after LASIK. Patients and methods: Sixty-seven eyes (34 patients) treated using the Automatic Corneal Shaper and the Keracor 117CT spot-scanning excimer laser were included. All eyes had best-corrected vision of 20/25 or better preoperatively. We measured spectacle refraction, visual acuity, and mesopic vision without and with glare (Nyktometer, Rodenstock) both preoperatively and 1 year after LASIK. Results were evaluated in three groups with reference to baseline refraction, and numbers of patients who saw a contrast of 1 : 5 or less were compared. Results: Myopia -1 to -5 D (group 1; n = 26): Preoperatively (postoperatively), 89 % (96 %) (P = 0.03) of eyes identified a contrast of 1 :5 or less without glare, while 65 % (73 %) achieved that level with glare. Myopia -5.1 to -10 D (group 2; n = 24): Preoperatively (postoperatively), 83 % (75 %) of eyes identified a contrast of 1 : 5 or less without glare, while 50 % (21 %) achieved that level with glare. Myopia -10.1 to -15 D (group 3; n = 11): Preoperatively (postoperatively), 73 % (55 %) of eyes identified a contrast of 1 :5 or less without glare, while 46 % (27 %) achieved that level with glare. Conclusions: LASIK seems to cause a reduction of mesopic vision under glare conditions in corrections of more than -5 D. In corrections of more than -10 D, mesopic vision without glare is reduced, too. However, differences were not statistically significant when comparing Vision at contrasts of 1 :5 and lower. In addition, mesopic is considerably reduced in high myopes even preoperatively.