Morphological Changes of Ciliary Body and Trabecular Meshwork

In Vivo Morphological Changes of Ciliary Body and Trabecular Meshwork in High Myopia Eyes With Open-angle Glaucoma in Their Accommodation Induced by Pilocarpine

Glaucoma is the leading cause of irreversible blindness worldwide. Although the pathogenesis remains unclear, pathologic increase in intraocular pressure (IOP) due to blocked aqueous outflow through the trabecular-Schlemm canal is known to be an important risk factor, and reduction of IOP is the only clinically validated way to retard the progression of OAG. Ciliary muscle plays a central role in the trabecular meshwork-Schlemm canal outflow pathway. Clinical evidence suggests that ciliary muscle contraction stimulated by cholinergic receptor agonist and retraction of ciliary body position after cataract surgery can dilate the lumen of Schlemm canal and reduce IOP. Currently, Ultrasound biomicroscopy (UBM) can obtain two-dimensional images of the anterior segment using high-frequency Ultrasound transducers in medical imaging studies of the ciliary body - trabecular meshwork -Schlemm canal complex. UBM has better tissue penetration than Optical coherence tomography (OCT) and can image the ciliary body better, but it has a lower resolution (30um to 50um) and is poor at imaging tiny tissues such as trabecular meshwork and Schlemm canal. The latest swept-source OCT (SS-OCT) has faster image capture rate (1000000 A scans/SEC), stronger penetration and higher resolution (8um axial resolution and 20um transverse resolution). The structure and morphology of ciliary body-trabecular meshwork-Schlemm canal complex can be clearly photographed. The investigators intend to use CASIA2 to image the ciliary body-trabecular meshwork-Schlemm canal complex before and after administration of pilocarpine in healthy individuals and patients with glaucoma to assess the effect of pilocarpine on the anatomy of the ciliary body-trabecular meshwork-Schlemm canal complex.

Study Overview

• Status: Not yet recruiting
• Conditions: Glaucoma; Myopia
• Intervention / Treatment: Drug: 0.5% pilocarpine eye drops

Detailed Description

Glaucoma is the leading cause of irreversible blindness worldwide. Although the pathogenesis remains unclear, pathologic increase in intraocular pressure (IOP) due to blocked aqueous outflow through the trabecular-Schlemm canal is known to be an important risk factor, and reduction of IOP is the only clinically validated way to retard the progression of OAG. Ciliary muscle plays a central role in the trabecular meshwork-Schlemm canal outflow pathway. When the ciliary muscle contraction, the elastic fiber network will pull trabecular meshwork away from Schlemm canal direction, trabecular meshwork and adjacent tissue gap increases, increasing aqueous outflow. Clinical evidence suggests that ciliary muscle contraction stimulated by cholinergic receptor agonist and retraction of ciliary body position after cataract surgery can dilate the lumen of Schlemm canal and reduce IOP. Currently, Ultrasound biomicroscopy (UBM) can obtain two-dimensional images of the anterior segment using high-frequency Ultrasound transducers in medical imaging studies of the ciliary body - trabecular meshwork -Schlemm canal complex. UBM has better tissue penetration than Optical coherence tomography (OCT) and can image the ciliary body better, but it has a lower resolution (30um to 50um) and is poor at imaging tiny tissues such as trabecular meshwork and Schlemm canal. The latest swept-source OCT (SS-OCT) has faster image capture rate (1000000 A scans/SEC), stronger penetration and higher resolution (8um axial resolution and 20um transverse resolution). The structure and morphology of ciliary body-trabecular meshwork-Schlemm canal complex can be clearly photographed. The novel anterior segment optical coherence tomography (AS-OCT) device, CASIA2 can accurately image the ciliary body-trabecular meshwork-Schlemm canal complex. The investigators intend to use CASIA2 to image the ciliary body-trabecular meshwork-Schlemm canal complex before and after administration of pilocarpine in healthy individuals and patients with glaucoma to assess the effect of pilocarpine on the anatomy of the ciliary body-trabecular meshwork-Schlemm canal complex.

• Study Type: Interventional
• Enrollment (Anticipated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: zhangliang LI; Phone Number: 13968832833; Email: lizhangliang0328@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Emmetropia/low myopia,high myopia, primary open-angle glaucoma without high myopia, and high myopia with primary open-angle glaucoma
• have a good gaze to complete the test required inspection;

Exclusion Criteria:

• hypersensitivity to pilocarpine
• History of eye surgery, including cataract surgery, anti-glaucoma surgery, corneal surgery, retinal surgery, and eye trauma
• history of systemic diseases that may affect the eyes (such as diabetes, hypertension, etc.)
• intraocular chronic inflammatory diseases (uveitis, etc.), retinal diseases (retinal detachment, diabetic retinopathy, retinitis pigmentosa, etc.)
• Corneal scars and severe cataracts affect OCT imaging
• Eye diseases (angle-closure glaucoma, abnormal anterior segment development, neovascularization, etc.) that can affect trabecular meshwork and Schlemm canal structure.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Health control; emmetropia/low myopia (equivalent spherical lens > -3.00d, astigmatism ≤ 1.5d), best corrected visual acuity ≥1.0	Drug: 0.5% pilocarpine eye drops; Subjects will be given 0.5% pilocarpine eye drops every five minutes for three times and wait for 40 minutes
Experimental: High myopia; Equivalent spherical lens ≤-6.00D or axial length ≥26.5mm	Drug: 0.5% pilocarpine eye drops; Subjects will be given 0.5% pilocarpine eye drops every five minutes for three times and wait for 40 minutes
Experimental: Primary open angle glaucoma; emmetropia/low myopia (equivalent spherical lens > -3.00d, astigmatism ≤ 1.5d), diagnosed as POAG	Drug: 0.5% pilocarpine eye drops; Subjects will be given 0.5% pilocarpine eye drops every five minutes for three times and wait for 40 minutes
Experimental: HM-POAG; Equivalent spherical lens ≤-6.00D or axial length ≥26.5mm，diagnosed as POAG	Drug: 0.5% pilocarpine eye drops; Subjects will be given 0.5% pilocarpine eye drops every five minutes for three times and wait for 40 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Morphology of ciliary body	measurement of Morphology of ciliary body using CAISA2(The novel anterior segment optical coherence tomography (AS-OCT) device) and Image J software	baseline, pre-intervention(local application of pilocarpine eye drops)
Morphology of ciliary body	measurement of Morphology of ciliary body using CAISA2(The novel anterior segment optical coherence tomography (AS-OCT) device) and Image J software	40 minutes after the intervention(local application of pilocarpine eye drops)
Morphology of trabecular meshwork	measurement of Morphology of trabecular meshwork using CAISA2(The novel anterior segment optical coherence tomography (AS-OCT) device) and Image J software	baseline, pre-intervention(local application of pilocarpine eye drops)
Morphology of trabecular meshwork	measurement of Morphology of trabecular meshwork using CAISA2(The novel anterior segment optical coherence tomography (AS-OCT) device) and Image J software	40 minutes after the intervention(local application of pilocarpine eye drops)

Collaborators and Investigators

• Sponsor: Yune Zhao
• Investigators: Principal Investigator: Yune Zhao, Ophthalmology and Optometry Hospital

Study record dates

Study Major Dates

• Study Start (Anticipated): May 1, 2022
• Primary Completion (Anticipated): June 1, 2022
• Study Completion (Anticipated): August 1, 2022

Study Registration Dates

• First Submitted: April 17, 2022
• First Submitted That Met QC Criteria: April 24, 2022
• First Posted (Actual): April 29, 2022

Study Record Updates

• Last Update Posted (Actual): April 29, 2022
• Last Update Submitted That Met QC Criteria: April 24, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Keywords: ciliary body and trabecular meshwork
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Refractive Errors; Glaucoma; Myopia; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Cholinergic Agents; Cholinergic Agonists; Pharmaceutical Solutions; Miotics; Muscarinic Agonists; Ophthalmic Solutions; Pilocarpine
• Other Study ID Numbers: Myopia-OAG SSOCT

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No