Eyelid squinting improves near vision in against-the-rule and distance vision in with-the-rule astigmatism in pseudophakic eyes: an eye model experimental study

Jay Won Rhim,Youngsub Eom,Jong Suk Song,Su-Yeon Kang,Hyo Myung Kim,Seo Yeon Park

doi:10.1186/s12886-019-1297-5

Jay Won Rhim, Youngsub Eom + Show 4 more

Open Access

PDF Available

https://doi.org/10.1186/s12886-019-1297-5

Copy DOI

Export

Save

Cite

Journal: BMC Ophthalmology	Publication Date: Jan 2, 2020
Citations: 4	License type: open-access

Affiliation: Korea University, Ansan University

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

BackgroundTo elucidate whether eyelid squinting improves near and distance vision in against-the-rule (ATR) and with-the-rule (WTR) simple myopic astigmatism in pseudophakic eyes.MethodsA refraction-model eye was mounted on a wavefront analyzer. The eyelid fissure was simulated using a slit placed horizontally in front of the model eye. Four different refractive statuses [− 1.50 diopters (D) and − 3.00 D of both WTR and ATR simple myopic astigmatism] were set using cylindrical lenses. For each refractive status (emmetropia, − 1.50 D WTR, − 1.50 D ATR, − 3.00 D WTR, and − 3.00 D ATR astigmatism), wavefront aberrations were measured, both with and without the slit, 40 times each.ResultsThe 2 mm horizontal slit caused a hyperopic focus shift (+ 6.69 μm) in − 1.50 D WTR astigmatism, whereas, in − 1.50 D ATR astigmatism, it caused a myopic focus shift (− 2.01 μm). The astigmatism was decreased in the ATR astigmatism groups and increased in the emmetropia and WTR astigmatism groups, respectively. Total aberrations were decreased in the emmetropia and WTR astigmatism groups and increased in the ATR astigmatism groups. When the reference plane was set to the near plane, total aberrations were decreased in the ATR astigmatism groups.ConclusionAs the horizontal slit was placed in front of the model eye, the focus moves nearer in ATR astigmatism and farther in WTR astigmatism. These effects of eyelid cause improvement of near vision of pseudophakic eyes with ATR astigmatism.

Highlights

To elucidate whether eyelid squinting improves near and distance vision in against-the-rule (ATR) and with-the-rule (WTR) simple myopic astigmatism in pseudophakic eyes
To date, most clinical trials that address the topic of vision have been performed using visual acuity (VA) at distance and near as the standard outcome parameters, because refractive state as well as the effects of aberration on VA are of utmost interest to ophthalmologists [1]
Many studies have addressed the pseudoaccommodation effect of astigmatism, and near vision is known to be impacted by the magnitude and meridian of astigmatism, [3,4,5,6,7,8,9,10,11,12,13,14] pupil size, [15,16,17,18,19,20] and the shape of the optotype [21,22,23]

Summary

Introduction

To elucidate whether eyelid squinting improves near and distance vision in against-the-rule (ATR) and with-the-rule (WTR) simple myopic astigmatism in pseudophakic eyes. Investigations performing a visual quality comparison between with-the-rule (WTR) and against-the-rule (ATR) astigmatism have shown (2020) 20:4 discordant results, likely because of differences in their methods, outcome measures, and influencing factors. For this reason, precise conclusions cannot be drawn as to whether WTR or ATR astigmatism is better for near vision [3,4,5,6,7,8,9,10,11,12,13,14, 24]. The definitive reason for this finding is unclear; it may be an artifact of the use of the Latin alphabet, in that the letters have a greater vertical than horizontal component [2]

Methods

Results

Conclusion