Regional Changes of Iris Stiffness in the Rabbits Suffered from Chronic High Intraocular Pressure
- PDF / 1,615,117 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 113 Downloads / 168 Views
ORIGINAL ARTICLE
Regional Changes of Iris Stiffness in the Rabbits Suffered from Chronic High Intraocular Pressure Tan Li1,2,3 · Xiao Qin1,2 · Haixia Zhang1,2 · Lin Li1,2 · Zhicheng Liu1,2 Received: 24 July 2020 / Accepted: 5 November 2020 © Taiwanese Society of Biomedical Engineering 2020
Abstract Purpose To explore the effects of chronic high intraocular pressure (IOP) on the iris stiffness in different regions (iris root, mid-periphery and pupillary-margin). Methods We established rabbit animal models with chronic high IOP by injecting α-chymotrypsin into the posterior chamber of the left eyes of rabbits, while their right eyes were regarded as self-blank control eyes. After a 26-week duration of chronic high IOP, rabbits were sacrificed and irises were removed from the eyes globe. The iris stiffness in different regions was measured by atomic force microscope. Results The iris in treated eye was significantly stiffer than that in control eye in iris root (1.9 times), mid-periphery (2.0 times) and pupillary-margin (2.3 times), p < 0.05. In treated eye, the iris in pupillary-margin was significantly stiffer than that in iris root and mid-periphery, p < 0.05. In control eye, the iris in pupillary-margin was significantly stiffer than that in mid-periphery, p < 0.05. Histological analysis showed that in treated eye, the iris thinned and the number of iris pigment cells in the stroma decreased. Conclusions Under chronic high IOP, rabbit iris stiffness increases. The difference in mean iris stiffness between pupillarymargin and mid-periphery in the treated eye is higher than that in the control eye. It needs to investigate whether the regional difference of iris stiffness affects the flow field of aqueous humor in the anterior segment and leads to further elevation of IOP. Keywords Elastic modulus · Iris · Stroma · Chronic high intraocular pressure · Dilator
1 Introduction Chronic high intraocular pressure (IOP) (also known as ocular hypertension (OHT)) is the main risk factor for glaucoma [1]. IOP changes dynamically which is affected by the flow of aqueous humor. The aqueous humor is generated by the ciliary body, flows through the iris-lens canal in the posterior chamber [2], passes through the pupil, enters the anterior * Lin Li [email protected] 1
School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
2
Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, China
3
State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
chamber, and finally gets out of the eye through trabecular meshwork channel. The iris is surrounded by aqueous humor. According to the theory of biomechanics, iris shape is related to the pressure from the aqueous humor and its own mechanical properties. Abnormal iris shape is a contributing factor to high IOP [3]. The the
Data Loading...
