Visual quality after monovision correction by laser in situ keratomileusis in presbyopic patients.

PURPOSE: To evaluate visual quality after laser in situ keratomileusis (LASIK) performed to achieve monovision in presbyopic patients.

SETTING: Laboratory of Vision Sciences and Applications, Department of Optics, University of Granada, Granada, and Clínica Novovisión, Madrid, Spain.

DESIGN: Cohort study.

METHODS: Laser in situ keratomileusis was performed with the Allegretto Wave Eye-Q 400 Hz laser. The dominant eye was corrected for far vision and the nondominant eye for near vision by targeting -1.25 diopters of myopia. The F-CAT algorithm was programmed targeting a postsurgical corneal asphericity of -0.80 in the dominant eye and -1.00 in the nondominant eye. Visual acuity, contrast sensitivity function, ocular aberrations, stereoacuity, the scattering index, and the visual-discrimination capacity were analyzed preoperatively and 3 months postoperatively.

RESULTS: The study enrolled 25 patients (50 eyes) with a mean age of 49.3 years ± 4.5 (SD). Postoperatively, more than 90% of patients had a binocular uncorrected distance and near visual acuity of 0.0 logMAR or better, although the contrast sensitivity function diminished, especially in the nondominant eye and with binocular vision. Stereoacuity was significantly worse in all patients (P<.001). The visual discrimination capacity declined in nondominant eyes and under binocular conditions (P<.005); no significant changes occurred in dominant eyes (P=.614). In all eyes, the mean objective scatter index value increased postoperatively, but not significantly (P>.05).

CONCLUSIONS: Monovision correction by LASIK improved functional near vision in presbyopic patients. Although visual acuity was good for far vision, contrast sensitivity and stereoacuity diminished significantly.