Crosbie Darragh E, Keaney James, Tam Lawrence C S, Daniel Stamer W, Campbell Matthew, Humphries Peter
Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland.
Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland; Ross University School of Veterinary Medicine, P. O. Box 334, Basseterre, St. Kitts, Saint Kitts and Nevis.
Magn Reson Imaging. 2019 Jun;59:10-16. doi: 10.1016/j.mri.2019.01.016. Epub 2019 Jan 17.
Here, we are testing the hypothesis that dynamic contrast enhanced MRI (DCE-MRI) is a useful approach for non-invasively evaluating age-related changes in aqueous humor outflow and its contribution to elevated intraocular pressure in the DBA/2J model of pigmentary glaucoma.
A rodent-specific 7 T MRI was used to assess eye anatomy (anterior chamber (AC) and vitreous body (VB) morphology, eye size, lens size) and aqueous humor dynamics (via intravenous administration of Gd-DTPA and Gd-BOPTA contrast agents) in C57BL/6 and DBA/2J mice at 3 and 9 months of age.
Gd-MRI was used to demonstrate an anterior solute pathway into the mouse AC. Topical latanoprost treatment in C57BL/6J mice reduced Gd-BOPTA accumulation in the AC. Age-related increases in AC area, AC depth and eye size were observed in DBA/2J mice compared to C57BL/6J mice. The rate of Gd-DTPA accumulation and peak Gd-DTPA intensity was lowest in 9-month old DBA/2J mice compared to 3-month old DBA/2J mice and C57BL/6J mice at both ages. Leakage of Gd-DTPA posteriorly into the VB was also observed in 9-month old DBA/2J mice.
These studies support the idea that age-related changes in aqueous humor outflow contribute to elevated intraocular pressure (IOP) in the DBA/2J model of pigmentary glaucoma. Gd-MRI is a valuable tool for better understanding of mechanisms and dynamics of aqueous humor circulation in normal and glaucomatous mouse eyes or following topical administration of medicines to reduce IOP.
在此，我们正在检验这样一个假设，即动态对比增强磁共振成像（DCE-MRI）是一种用于非侵入性评估色素性青光眼DBA/2J模型中房水流出与年龄相关变化及其对眼压升高的作用的有用方法。
使用啮齿动物专用的7T MRI来评估C57BL/6和DBA/2J小鼠在3个月和9个月大时的眼部解剖结构（前房（AC）和玻璃体（VB）形态、眼睛大小、晶状体大小）和房水动力学（通过静脉注射钆喷酸葡胺（Gd-DTPA）和钆双胺（Gd-BOPTA）造影剂）。
钆MRI用于证明存在一条进入小鼠前房的前部溶质途径。C57BL/6J小鼠局部使用拉坦前列素治疗可减少前房中Gd-BOPTA的积聚。与C57BL/6J小鼠相比，DBA/2J小鼠中观察到前房面积、前房深度和眼睛大小与年龄相关的增加。与3个月大的DBA/2J小鼠以及两个年龄段的C57BL/6J小鼠相比，9个月大的DBA/2J小鼠中Gd-DTPA的积聚速率和Gd-DTPA峰值强度最低。在9个月大的DBA/2J小鼠中还观察到Gd-DTPA向后渗漏到玻璃体中。
这些研究支持这样一种观点，即色素性青光眼DBA/2J模型中房水流出与年龄相关的变化导致眼压升高。钆MRI是一种有价值的工具，可用于更好地理解正常和青光眼小鼠眼中房水循环的机制和动力学，或在局部给药降低眼压后进行研究。
