Pupil Size Associated with the Largest Iris Volume in Normal Chinese Eyes.

Shuning Li,Shi-Ming Li,Ningli Wang,Yiquan Yang,Jing Jiang,Gewei Wu,Ravi Thomas

doi:10.1155/2018/8058951

Abstract

Background To determine the range of pupil size that has the largest iris volume in normal eyes. Methods 31 healthy adult Chinese volunteers underwent swept-source anterior segment OCT examination in both eyes. Pilocarpine 1% was instilled in a randomly selected eye (eye with induced miosis (ME)) of each participant to obtain iris volume (IV) measurements over a range of pupil sizes. OCT was performed prior to and one hour after pilocarpine in both ME and fellow eye (FE). Iris volume (IV), anterior chamber volume (ACV), anterior chamber depth (ACD), and pupil size (PS) were recorded. A scatter plot was used to depict the association between each pupil size and IV. Results The pupillary sizes for which IV was recorded in ME and FE ranged from 1.161 mm to 6.665 mm. The mean IV increased with miosis in both ME and FE; in 13 eyes, IV decreased with a decrease in pupillary size. PS between 3.812 and 6.665 mm was associated with an increase in IV, while PS between 3.159 and 5.54 mm was associated with a decrease. The relationship between PS and IV was in the shape of a downward parabola and was modeled using a quadratic equation (y = −1.3121x2 + 8.8429x + 16.423, R2 = 0.26886). The largest IV occurred at PS between 3 and 4 mm. Conclusions The relationship between PS and IV in this study was in the shape of a downward parabola. The largest IV was recorded at a pupillary size between 3 and 4 mm. This trial is registered with ChiCTR-ROC-17013572.

Highlights

Primary angle-closure glaucoma (PACG) is one of the major causes of glaucoma and blindness in Capital Health Industry Development Research Special (China) [1]
Observations of IV over smaller pupil size (PS) induced by pharmacological miosis, while not physiological, may provide useful information about the relationship of iris volume with pupillary size and the PS at which IV is the maximum in normal people. e purpose of this study is to report the change in IV from physiological PS to pharmacologically induced miotic PS in healthy volunteers and assess the PS at which IV is the maximum
As the objective was to determine IV in eyes with decreased pupil size, these 10 eyes with an increase in PS were excluded. e IV decreased with smaller pupil size in 9 of 31 Miosis-induced eye (ME) and 4 of 21 fellow eye (FE) (Table 2). e range of baseline pupil size for eyes whose IV increased with miosis was 3.812–6.665 mm; it was 3.159–5.54 mm for those whose IV decreased

Summary

Background

To determine the range of pupil size that has the largest iris volume in normal eyes. Pilocarpine 1% was instilled in a randomly selected eye (eye with induced miosis (ME)) of each participant to obtain iris volume (IV) measurements over a range of pupil sizes. Iris volume (IV), anterior chamber volume (ACV), anterior chamber depth (ACD), and pupil size (PS) were recorded. E pupillary sizes for which IV was recorded in ME and FE ranged from 1.161 mm to 6.665 mm. E mean IV increased with miosis in both ME and FE; in 13 eyes, IV decreased with a decrease in pupillary size. E relationship between PS and IV was in the shape of a downward parabola and was modeled using a quadratic equation (y −1.3121x2 + 8.8429x + 16.423, R2 0.26886). E largest IV was recorded at a pupillary size between 3 and 4 mm. Conclusions. e relationship between PS and IV in this study was in the shape of a downward parabola. e largest IV was recorded at a pupillary size between 3 and 4 mm. is trial is registered with ChiCTR-ROC-17013572

Introduction

Results

Discussion