Morphological Changes of Ciliary Body and Trabecular Meshwork
Status:
Not yet recruiting
Trial end date:
2022-08-01
Target enrollment:
Participant gender:
Summary
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.