Functional Visual Acuity of Early Presbyopia

Yusaku Katada,Yuta Shigeno,Megumi Saiki,Kazuo Tsubota,Hidemasa Torii,Kazuhiro Watanabe,Kazuno Negishi,Minako Kaido,Choun-Ki Joo

doi:10.1371/journal.pone.0151094

Abstract

PurposeTo evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test.MethodsThis study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-corrected near FVA (DCNFVA) were measured using the FVA Measurement System. The standard Schirmer test and standard tear break-up time measurement also were performed.ResultsThe logarithm of the minimum angle of resolution (logMAR) DCVA was better than 0 in all subjects. The percentages of subjects with logMAR DCNVA below 0 was significantly lower in the presbyopia group than in the young group. The DCNFVA in the presbyopia group was significantly (P < 0.001) poorer than the DCNVA in that group. Significant linear negative correlations were seen between the DCNVA and AA (r = -0.507, P < 0.001) and the DCNFVA and AA (r = -0.681, P < 0.001) in the older subjects. Stepwise regression analysis showed that only the AA was a significant factor predictive of the DCNFVA in the presbyopia group. Tear function parameters were not adopted in the regression model.ConclusionsMeasurement of the DCNFVA can detect decreased AA in early presbyopia better than measurement of the conventional near VA. The DCNFVA is a good index for early presbyopia.

Highlights

Presbyopia is age-related loss of accommodation that results in near visual disturbance
Significant linear negative correlations were seen between the distance-corrected near VA (DCNVA) and accommodation amplitude (AA) (r = -0.507, P < 0.001) and the distance-corrected near FVA (DCNFVA) and AA (r = -0.681, P < 0.001) in the older subjects
Stepwise regression analysis showed that only the AA was a significant factor predictive of the DCNFVA in the presbyopia group

Summary

Introduction

Presbyopia is age-related loss of accommodation that results in near visual disturbance. Presbyopia is characterized by a variety of symptoms including decreased reading performance [1,2,3] and asthenopia or headache following close work even without decreased near visual acuity (VA).[4] The loss of accommodation is the main etiology of decreased near vision in normal aging subjects. To simulate functional vision of daily life, functional VA (FVA) was first defined by Goto et al[22]. In brief it is measured as the average of the visual acuities measured during a certain time frame, so it reflects daily vision more efficiently than measuring visual acuity at 1 specific point.

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