Comparison of Subjective Refraction under Binocular and Monocular Conditions in Myopic Subjects.

Hidenaga Kobashi,Tomoya Handa,Kimiya Shimizu,Wakako Ando,Kazutaka Kamiya,Akihito Igarashi,Takushi Kawamorita

doi:10.1038/srep12606

Hidenaga Kobashi, Tomoya Handa + Show 5 more

Open Access

https://doi.org/10.1038/srep12606

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Journal: Scientific reports	Publication Date: Jul 28, 2015
Citations: 14	License type: CC BY 4.0

Affiliation: Kitasato University

Abstract

To compare subjective refraction under binocular and monocular conditions, and to investigate the clinical factors affecting the difference in spherical refraction between the two conditions. We examined thirty eyes of 30 healthy subjects. Binocular and monocular refraction without cycloplegia was measured through circular polarizing lenses in both eyes, using the Landolt-C chart of the 3D visual function trainer-ORTe. Stepwise multiple regression analysis was used to assess the relations among several pairs of variables and the difference in spherical refraction in binocular and monocular conditions. Subjective spherical refraction in the monocular condition was significantly more myopic than that in the binocular condition (p < 0.001), whereas no significant differences were seen in subjective cylindrical refraction (p = 0.99). The explanatory variable relevant to the difference in spherical refraction between binocular and monocular conditions was the binocular spherical refraction (p = 0.032, partial regression coefficient B = 0.029) (adjusted R2 = 0.230). No significant correlation was seen with other clinical factors. Subjective spherical refraction in the monocular condition was significantly more myopic than that in the binocular condition. Eyes with higher degrees of myopia are more predisposed to show the large difference in spherical refraction between these two conditions.

Highlights

At present, in a clinical setting, we measure only subjective refraction, and that, only for monocular testing
We found significant differences in spherical refraction (p < 0.001, Wilcoxon’s signed rank sum test) and pupil diameter (p < 0.001) between binocular and monocular conditions, but no significant differences were found in cylindrical refraction (p = 0 .999) (Table 2)
The mean differences in spherical refraction and pupil diameter were − 0.20 ± 0 .27 diopter (D) (95% confidence interval (CI), 0.32 to − 0.72 D) and 1.40 ± 0 .52 mm, respectively

Summary

Introduction

In a clinical setting, we measure only subjective refraction, and that, only for monocular testing. The evaluation of visual performance under binocular conditions is important. A number of studies have advocated the importance of evaluating the binocular state in post-refractive surgery patients[2,3,4,5]. To our knowledge, there have so far been no clinical studies on subjective refraction under binocular conditions. 30% of patients after refractive surgery are dissatisfied their overcorrection[10]. To prevent overcorrection for ametropia, precise assessment of preoperative subjective refraction is necessary in order to acquire higher patient satisfaction. The purpose of this study is twofold: to prospectively compare subjective refraction under binocular and monocular conditions, and to investigate the clinical factors that affect the difference in spherical refraction between these two conditions using multivariate regression analysis

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Results