Clinical results of laser in situ keratomileusis with superior and nasal hinges

PURPOSE: To compare the differences in the clinical results of LASIK with a nasal corneal flap and with a superior corneal flap. SETTING: Department of Ophthalmology, Kangnam St. Mary's Hospital, Seoul, Korea. METHODS: This randomized prospective study comprised 30 patients whose age and degrees of myopia were similar. In 1 group (25 eyes), a superior hinge was made and in the other group (25 eyes), a nasal hinge was made. Uncorrected visual acuity (UCVA), spherical equivalent (SE), astigmatism, and corneal topographical change before surgery and 1 week and 2 and 6 months after surgery were compared. The tear breakup time (BUT) and the Schirmer test before surgery and 2 months postoperatively were also compared. RESULTS: At 6 months, there were no significant between-group differences in UCVA, SE, astigmatism, and corneal ablation decentration (P >.05). At 2 months, the results of BUT and the Schirmer tests were 6.80 seconds and 9.54 mm, respectively, in the nasal hinge group (P >.05) and 5.08 seconds and 6.05 mm, respectively, in the superior hinge group (P <.05). CONCLUSIONS: There were no between-group differences in UCVA, SE, astigmatism, and corneal ablation decentration at 6 months, but the BUT and Schirmer test results were aggravated after LASIK in the superior hinge group.