TY - JOUR
T1 - Increased iris stiffness in patients with a history of angle-closure glaucoma
T2 - An image-based inverse modeling analysis
AU - Pant, Anup Dev
AU - Gogte, Priyanka
AU - Pathak-Ray, Vanita
AU - Dorairaj, Syril K.
AU - Amini, Rouzbeh
N1 - Funding Information:
Supported by The Ohio Supercomputer Center (Columbus, OH, USA) resource grant that facilitated the computational aspect of the study. Disclosure: A.D. Pant, None; P. Gogte, None; V. Pathak-Ray, None; S.K. Dorairaj, None; R. Amini, None
Publisher Copyright:
© 2018 The Authors.
PY - 2018/8
Y1 - 2018/8
N2 - PURPOSE. Previous studies have shown that iris mechanical properties may play a role in the pathophysiology of primary angle-closure glaucoma (PACG). Such studies, however, were not conducted in vivo and as such were limited in application and scope, especially for the development of diagnostic methods or new treatment options. The purpose of this study was to quantify in vivo iris mechanical properties both in patients with a history of angle-closure glaucoma and in healthy volunteers. METHODS. We acquired optical coherence tomography scans of anterior segments under standard and dim light conditions. Using a combination of finite element simulation and an inverse fitting algorithm, we quantified the stiffness of the iris. RESULTS. The irides in the eyes of patients with a history of PACG were significantly stiffer when compared with healthy control irides, a result consistent with ex vivo studies. This result was independent of the compressibility assumption (incompressible: 0.97 ± 0.14 vs. 2.72 ± 0.71, P = 0.02; compressible: 0.89 ± 0.13 vs. 2.57 ± 0.69, P = 0.02) when comparing the normalized elastic modulus of the iris between patients with PACG and healthy controls. CONCLUSIONS. Our noninvasive, in vivo quantification is free of numerous ethical issues and potential limitations involved with ex vivo examinations. If further studies confirm that the iris stiffness is an omnipresent PACG risk factor and a mechanistic role between increased iris stiffness and angle-closure glaucoma does exist, treatment methods such as lowering the iris stiffness can be developed.
AB - PURPOSE. Previous studies have shown that iris mechanical properties may play a role in the pathophysiology of primary angle-closure glaucoma (PACG). Such studies, however, were not conducted in vivo and as such were limited in application and scope, especially for the development of diagnostic methods or new treatment options. The purpose of this study was to quantify in vivo iris mechanical properties both in patients with a history of angle-closure glaucoma and in healthy volunteers. METHODS. We acquired optical coherence tomography scans of anterior segments under standard and dim light conditions. Using a combination of finite element simulation and an inverse fitting algorithm, we quantified the stiffness of the iris. RESULTS. The irides in the eyes of patients with a history of PACG were significantly stiffer when compared with healthy control irides, a result consistent with ex vivo studies. This result was independent of the compressibility assumption (incompressible: 0.97 ± 0.14 vs. 2.72 ± 0.71, P = 0.02; compressible: 0.89 ± 0.13 vs. 2.57 ± 0.69, P = 0.02) when comparing the normalized elastic modulus of the iris between patients with PACG and healthy controls. CONCLUSIONS. Our noninvasive, in vivo quantification is free of numerous ethical issues and potential limitations involved with ex vivo examinations. If further studies confirm that the iris stiffness is an omnipresent PACG risk factor and a mechanistic role between increased iris stiffness and angle-closure glaucoma does exist, treatment methods such as lowering the iris stiffness can be developed.
KW - Biomechanics
KW - Elastic modulus
KW - Finite element analysis
KW - Image-based modeling
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U2 - 10.1167/iovs.18-24327
DO - 10.1167/iovs.18-24327
M3 - Article
C2 - 30105368
AN - SCOPUS:85052680850
SN - 0146-0404
VL - 59
SP - 4134
EP - 4142
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 10
ER -