Iris stromal cell nuclei deform to more elongated shapes during pharmacologically-induced miosis and mydriasis

Rashidi, Neda; Pant, Anup; Salinas, Samuel D.; Shah, Mickey; Thomas, Vineet S.; Zhang, Ge; Dorairaj, Syril; Amini, Rouzbeh

doi:10.1016/j.exer.2020.108373

Cited by 3 publications

(3 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These lesions can cause severe morphological changes to the iris structure and modify its biomechanical properties [8,9]. The iris structure can also be altered by drugs which can modify the normal miosis and mydriasis of the iris [10]. In addition to abnormal morphological changes, the iris also undergoes natural variations due to its function in the eye (contraction and expansion) [11].…”

Section: Introductionmentioning

confidence: 99%

Assessing Porcine Iris Elasticity and Mechanical Anisotropy with Optical Coherence Elastography

Zevallos-Delgado

Mekonnen

Zvietcovich

et al. 2021

J-BPE

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Assessing Porcine Iris Elasticity and Mechanical Anisotropy with Optical Coherence Elastography

Zevallos-Delgado

Mekonnen

Zvietcovich

et al. 2021

J-BPE

View full text Add to dashboard Cite

“…Pilocarpine stimulates cholinergic activity in the TM cells, leading to contraction [23]. This may also function to stimulate the contraction of the iris sphincter muscle to reduce the size of the pupil [29]. In this scenario, the pupils cannot dilate and contract freely, and the movement of the iris is restricted, closely related to the TM and SC.…”

Section: Discussionmentioning

confidence: 99%

Effects of Schlemm’s Canal Suture Implantation Surgery and Pilocarpine Eye Drops on Trabecular Meshwork Pulsatile Motion

Sang,

Du,

Xin

et al. 2023

Biomedicines

View full text Add to dashboard Cite

The trabecular meshwork is an important structure in the outflow pathway of aqueous humor, and its movement ability directly affects the resistance of aqueous humor outflow, thereby affecting the steady state of intraocular pressure (IOP). (1) Objective: The purpose of this study was to preliminarily estimate the effects of pilocarpine eye drops and trabeculotomy tunneling trabeculoplasty (3T) on trabecular meshwork (TM) pulsatile motion via phase-sensitive optical coherence tomography (Phs-OCT). (2) Method: In a prospective single-arm study, we mainly recruited patients with primary open-angle glaucoma who did not have a history of glaucoma surgery, and mainly excluded angle closure glaucoma and other diseases that may cause visual field damage. The maximum velocity (MV) and cumulative displacement (CDisp) of the TM were quantified via Phs-OCT. All subjects underwent Phs-OCT examinations before and after the use of pilocarpine eye drops. Then, all subjects received 3T surgery and examinations of IOP at baseline, 1 day, 1 week, 1 month, 3 months, and 6 months post-surgery. Phaco-OCT examinations were performed at 3 and 6 months post-surgery, and the measurements were compared and analyzed. (3) Results: The MV of TM before and after the use of pilocarpine eye drops was 21.32 ± 2.63 μm/s and 17.00 ± 2.43 μm/s. The CDisp of TM before and after the use of pilocarpine eye drops was 0.204 ± 0.034 μm and 0.184 ± 0.035 μm. After the use of pilocarpine eye drops, both the MV and CDisp significantly decreased compared to those before use (p < 0.001 and 0.013, respectively). The IOP decreased from baseline at 22.16 ± 5.23 mmHg to 15.85 ± 3.71 mmHg after 3 months post-surgery and from 16.33 ± 2.51 mmHg at 6 months post-surgery, showing statistically significant differences (p < 0.001). The use of glaucoma medication decreased from baseline at 3.63 ± 0.65 to 1.17 ± 1.75 at 3 months and 1.00 ± 1.51 at 6 months post-surgery; the differences were statistically significant (p < 0.001). Additionally, there was no statistically significant difference in the MV between 3 and 6 months after surgery compared to baseline (p = 0.404 and 0.139, respectively). Further, there was no statistically significant difference in the CDisp between 3 and 6 months after surgery compared to baseline (p = 0.560 and 0.576, respectively) (4) Conclusions: After the preliminary study, we found that pilocarpine eye drops can attenuate TM pulsatile motion, and that 3T surgery may reduce IOP without affecting the pulsatile motion status of the TM.

show abstract

“…Although it is likely that genetics influence iris stiffness, it is also likely that biological remodeling driven by mechanical loading can stiffen the iris, as is the case for most other connective tissues [152,153]. For instance, the iris stromal cell's nuclei elongate in response to iridial muscle contractions [154 ▪▪ ], and mechanostimulation of nuclei can trigger the secretion of ECM proteins to change (remodel) the surrounding tissue, including stiffness [155]. Interestingly, iris biomechanics can also play a secondary role in complications associated with PACG.…”

Section: Biomechanical Factors In Angle-closure Glaucomamentioning

confidence: 99%

Glaucoma and biomechanics

Safa

Wong

et al. 2021

Current Opinion in Ophthalmology

View full text Add to dashboard Cite

Purpose of reviewBiomechanics is an important aspect of the complex family of diseases known as the glaucomas. Here, we review recent studies of biomechanics in glaucoma. Recent findingsSeveral tissues have direct and/or indirect biomechanical roles in various forms of glaucoma, including the trabecular meshwork, cornea, peripapillary sclera, optic nerve head/sheath, and iris. Multiple mechanosensory mechanisms and signaling pathways continue to be identified in both the trabecular meshwork and optic nerve head. Further, the recent literature describes a variety of approaches for investigating the role of tissue biomechanics as a risk factor for glaucoma, including pathological stiffening of the trabecular meshwork, peripapillary scleral structural changes, and remodeling of the optic nerve head. Finally, there have been advances in incorporating biomechanical information in glaucoma prognoses, including corneal biomechanical parameters and iridial mechanical properties in angle-closure glaucoma.

show abstract

Iris stromal cell nuclei deform to more elongated shapes during pharmacologically-induced miosis and mydriasis

Cited by 3 publications

References 54 publications

Assessing Porcine Iris Elasticity and Mechanical Anisotropy with Optical Coherence Elastography

Assessing Porcine Iris Elasticity and Mechanical Anisotropy with Optical Coherence Elastography

Effects of Schlemm’s Canal Suture Implantation Surgery and Pilocarpine Eye Drops on Trabecular Meshwork Pulsatile Motion

Glaucoma and biomechanics

Contact Info

Product

Resources

About