Glaucoma Center of Excellence, Wilmer Eye Institute at Johns Hopkins University, Baltimore, Maryland, USA.
Invest Ophthalmol Vis Sci. 2013 Mar 11;54(3):1767-80. doi: 10.1167/iovs.12-10952.
To study anatomical changes and mechanical behavior of the sclera in mice with experimental glaucoma by comparing CD1 to B6 mice.
Chronic experimental glaucoma for 6 weeks was produced in 2- to 4-month-old CD1 (43 eyes) and B6 mice (42 eyes) using polystyrene bead injection into the anterior chamber with 126 control CD1 and 128 control B6 eyes. Intraocular pressure (IOP) measurements were made with the TonoLab at baseline and after bead injection. Axial length and scleral thickness were measured after sacrifice in the CD1 and B6 animals and compared to length data from 78 eyes of DBA/2J mice. Inflation testing of posterior sclera was conducted, and circumferential and meridional strain components were determined from the displacement response.
Experimental glaucoma led to increases in axial length and width by comparison to fellow eyes (6% in CD1 and 10% in B6; all P < 0.03). While the peripapillary sclera became thinner in both mouse types with glaucoma, the remainder of the sclera uniformly thinned in CD1, but thickened in B6. Peripapillary sclera in CD1 controls had significantly greater temporal meridional strain than B6 and had differences in the ratios of meridional to effective circumferential strain from B6 mice. In both CD1 and B6 mice, exposure to chronic IOP elevation resulted in stiffer pressure-strain responses for both the effective circumferential and meridional strains (multivariable regression model, P = 0.01-0.03).
Longer eyes, greater scleral strain in some directions at baseline, and generalized scleral thinning after glaucoma were characteristic of CD1 mice that have greater tendency to retinal ganglion cell damage than B6 mice. Increased scleral stiffness after glaucoma exposure in mice mimics findings in monkey and human glaucoma eyes.
通过比较 CD1 与 B6 小鼠，研究实验性青光眼小鼠巩膜的解剖学变化和力学行为。
用聚苯乙烯珠从前房注射入 2-4 月龄的 CD1（43 只眼）和 B6（42 只眼）小鼠，制作 6 周慢性实验性青光眼。在珠注射前后用 TonoLab 测量眼内压（IOP）。处死 CD1 和 B6 动物后测量眼轴长度和巩膜厚度，并与 DBA/2J 小鼠的 78 只眼的长度数据进行比较。对后巩膜进行充气试验，根据位移响应确定周向和经向应变分量。
与对侧眼相比，实验性青光眼导致眼轴长度和宽度增加（CD1 增加 6%，B6 增加 10%；均 P<0.03）。虽然两种小鼠的视盘周围巩膜变薄，但 CD1 的其余巩膜均匀变薄，而 B6 的巩膜则变厚。CD1 对照组视盘周围巩膜的颞向经向应变明显大于 B6，并且经向与有效周向应变的比值与 B6 小鼠不同。在 CD1 和 B6 小鼠中，慢性 IOP 升高导致有效周向和经向应变的压力-应变响应更加僵硬（多变量回归模型，P=0.01-0.03）。
较长的眼轴、基线时某些方向更大的巩膜应变以及青光眼后巩膜的普遍变薄是 CD1 小鼠的特征，其视网膜神经节细胞损伤的倾向大于 B6 小鼠。青光眼后小鼠巩膜硬度增加，模拟了猴子和人青光眼眼的发现。
