Novel Discoveries of Anterior Segment Parameters in Fellow Eyes of Acute Primary Angle Closure and Chronic Primary Angle Closure Glaucoma

You, Shuqi; Liang, Zhiqiao; Yang, Kangyi; Oatts, Julius T.; Han, Ying; Wu, Huijuan

doi:10.1167/iovs.62.14.6

Cited by 14 publications

(15 citation statements)

References 35 publications

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“…Contrary to the current study, some previous studies found eyes with angle closure had larger ciliary body [16][17] . And it was proved that Valsalva manoeuvre could cause thickening of the ciliary body and induce narrowing of the angle [18] .…”

Section: Discussioncontrasting

confidence: 99%

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure

Chen¹,

Yan²,

Fan³

et al. 2022

Int J Ophthalmol

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AIM: To compare the ciliary body thickness between eyes with primary angle closure (PAC) and primary angle-closure glaucoma (PACG) with the normal eyes, and to investigate the association between ciliary body thickness and ciliary processes situation. METHODS: In this cross-sectional study, 57 patients with PAC/PACG were matched to 57 normal subjects after propensity score matching (PSM) adjusting for age and gender. All subjects underwent conventional ocular examinations and ultrasound biomicroscopy (UBM) examination, among which the patients with PAC/PACG performed the examinations one month after laser peripheral iridotomy (LPI). Quantitative parameters were measured, which included ciliary body thickness at the position of 1 mm posterior to the scleral spur (CBT1), trabecular-ciliary process distance (TCPD) and trabecular-ciliary process angle (TCA). RESULTS: Eyes with PAC/PACG presented significantly thinner CBT1, shorter TCPD and smaller TCA (P<0.001) than the normal eyes, both in comparison of the means of four quadrants and in comparisons of each quadrant. After removing images with peripheral anterior synechia (PAS), the same results were also found in comparisons between the two groups. Significant correlations were found between TCPD (R2=0.537, P<0.001) and TCA (R2=0.517, P<0.001) with CBT1. CONCLUSION: Eyes with PAC/PACG have thinner ciliary body thickness and more anteriorly situated ciliary processes. Thinner ciliary body thickness is associated with anterior situation of the ciliary processes.

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Section: Discussioncontrasting

confidence: 99%

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure

Chen¹,

Yan²,

Fan³

et al. 2022

Int J Ophthalmol

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“…The iris plays a central role in PACG. Worldwide, PACG is the second most prevalent form of glaucoma, although in some regions, primarily in parts of East Asia, PACG is the most prevalent form [24]. Current risk assessment in PACG patients is based on precise anatomical measurements of the anterior chamber and iris, e.g., by optical coherence tomographic (OCT) imaging [3,25], yet the predictive power of such techniques is poor [5].…”

Section: Discussionmentioning

confidence: 99%

“…We speculate that populations of European descent have a larger T s : E than Asian populations, due to several related observations. First, PACG is more prevalent in Asia, including both India and Singapore, than in the rest of the world [24]. Second, PACG patients have stiffer irides [7,8].…”

Section: Discussionmentioning

confidence: 99%

In vivobiomechanical assessment of iridial deformations and muscle contractions in human eyes

Safa

Fard

Ethier

2022

J. R. Soc. Interface.

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The iris is a muscular organ whose deformations can cause primary angle-closure glaucoma (PACG), a leading cause of blindness. PACG risk assessment does not consider iridial biomechanical factors, despite their expected influence on iris deformations. Here, we exploited an existing biometric dataset consisting of near-infrared movies acquired during the pupillary light reflex (PLR) as a unique resource to study iris biomechanics. The PLR caused significant (greater than 100%) and essentially spatially uniform radial strains in the iris in vivo , consistent with previous findings. Inverse finite-element modelling showed that sphincter muscle tractions were ca fivefold greater than iridial stroma stiffness (range 4- to 13-fold, depending on sphincter muscle size). This muscle traction is greater than has been previously estimated, which may be due to methodological differences and/or to different patient populations in our study (European descent) versus previous studies (Asian); the latter possibility is of particular interest due to differential incidence rates of PACG in these populations. Our methodology is fast and inexpensive and may be a useful tool in understanding biomechanical factors contributing to PACG.

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“…Worldwide, PACG is the second most prevalent form of glaucoma, although in some regions, primarily in parts of East Asia, PACG is the most prevalent form (Cheng et al 2014). Current risk assessment in PACG patients is based on precise anatomical measurements of the anterior chamber and iris, usually by optical coherence tomographic (OCT) imaging (Friedman et al 2012;You et al 2021), yet the predictive power of such techniques is poor (He et al 2019) 3E). There are multiple interrelated factors that likely influence this difference, as follows.…”

Section: Discussionmentioning

confidence: 99%

In vivo Biomechanical Assessment of Iridial Deformations and Muscle Contractions in Human Eyes

Safa

Fard

Ethier

2022

Preprint

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The iris is a muscular organ whose deformations can cause primary angle-closure glaucoma (PACG), a leading cause of blindness. PACG risk assessment does not consider iridial biomechanical factors, despite their expected influence on iris deformations. Here we exploited an existing biometric data set consisting of near-infrared movies acquired during the pupillary light reflex (PLR) as a unique resource to study iris biomechanics. The PLR caused significant (>100%) and essentially spatially uniform radial strains in the iris in vivo, consistent with previous findings. Inverse finite element modeling showed that sphincter muscle tractions were c. 5-fold greater than iridial stroma stiffness (range 4- to 13-fold, depending on sphincter muscle size). This muscle traction is greater than has been previously estimated, which may be due to methodological differences and/or to different patient populations in our study (European descent) vs. previous studies (Asian); the latter possibility is of particular interest due to differential incidence rates of PACG in these populations. Our methodology is fast and inexpensive and may be a useful tool in understanding biomechanical factors contributing to PACG.

show abstract

Novel Discoveries of Anterior Segment Parameters in Fellow Eyes of Acute Primary Angle Closure and Chronic Primary Angle Closure Glaucoma

Cited by 14 publications

References 35 publications

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure

In vivobiomechanical assessment of iridial deformations and muscle contractions in human eyes

In vivo Biomechanical Assessment of Iridial Deformations and Muscle Contractions in Human Eyes

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