Effect of Correction Lens for Anisometropia on Aniseikonia and Binocular Function

ABSTRACT

PURPOSE: To study the effect of the corrective lens for anisometropia on aniseikonia and binocular function. METHODS: The study subjects were 30 patients without strabismus and amblyopia, who had anisometropia of more than 1.00D between the spherical equivalent of each correction lens. The amount of aniseikonia was measured by Awaya's New Aniseikonia Test. The degree of stereopsis and fusion were determined with Titmus Stereo Test and fusion card of major amblyoscope, respectively. RESULTS: The amount of aniseikonia increased significantly with increasing level of anisometropia (p=0.000). There was a statistically significant correlation between the amount of anisometropia and fusion (p=0.046). With increased aniseikonia, the stereopsis declined consequently, but the decline was not statistically significant. Aniseikonia was induced when there was more than 2.00D of anisometropia. With anisometropia increased by 1.00D, the odds ratio of induced aniseikonia was 7.197 (p=0.047). CONCLUSIONS: Anisometropia is an important factor for aniseikonia and can disturb binocular function.