Effect of artificial anisometropia in dominant and nondominant eyes on stereoacuity

Abstract Objective To evaluate the effect of artificial anisometropia in dominant and nondominant eyes on stereoacuity. Methods In this descriptive analytic study, 60 healthy adult volunteers 18–37 years of age (mean age: 25.58 years) without any ocular disease were enrolled at Tabriz Nikookari eye hospital over a 1-year period. Anisometropia (unilateral myopia) was induced by placing trial lenses over the dominant and nondominant eyes in 1-diopter (D) increments ranging from 1 to 3 D. Stereoacuity was measured using the TNO, Randot, and Titmus stereotests and values were converted into Napierian logarithm (ln) and compared between the 2 eyes. Results Of the 60 adults (25 male and 35 female subjects), the right eye was dominant in 49 (81.7%) of the cases. Stereoacuity levels were reduced proportionately to the degree of anisometropia in all participants. Mean stereoacuity was 4.3, 5.5, and 7.4 ln for dominant eyes and 4.1, 5.4, and 7.3 ln for nondominant eyes using the TNO test by applying 1, 2, and 3 D lenses, respectively ( p > 0.05). Corresponding values were 3.5, 4.6, and 6.6 ln for dominant eyes and 3.4, 4.6, and 6.5 ln for nondominant eyes by the circles subcategory of Randot test, respectively ( p > 0.05). The scores were 3.8, 4.7, and 6.5 ln for dominant eyes and 3.8, 4.7, and 6.4 ln for nondominant eyes by the circles subcategory of Titmus test, respectively ( p > 0.05). Conclusion Artificial anisometropia could reduce stereoacuity. However, ocular dominance has no effect on the amount of stereoacuity reduction.