Morrison John C, Cepurna William, Ing Eliesa, Johnson Elaine, Abtin Aryana, Wentzien Susan, White Elizabeth, Lozano Diana C
Casey Eye Institute, Oregon Health & Science University, United States.
Casey Eye Institute, Oregon Health & Science University, United States.
Exp Eye Res. 2025 Feb;251:110237. doi: 10.1016/j.exer.2025.110237. Epub 2025 Jan 11.
Animal models that help us understand how elevated intraocular pressure (IOP) causes axonal injury will lead to new glaucoma therapies. Because reliable measurements are difficult to obtain in chronic models, we developed the controlled elevation of IOP (CEI) approach. Here, a cannula connected to an elevated balanced salt solution (BSS) reservoir is inserted into the anterior chamber of anesthetized Brown Norway rats. The extent and duration of IOP exposure is controlled by adjusting the reservoir height. We now describe a method for creating CEI in awake animals. A Pinport, which has a silicone plug that can be penetrated repeatedly, is modified, attached to the skull, and connected to a microcannula that is implanted in the posterior chamber. To elevate IOP, BSS from a reservoir is allowed to flow through a pressure transducer to a swivel-mounted tether and injector. The injector is placed on the Pinport, bypassing the need for anterior chamber cannulation and general anesthesia during CEI. The surgical technique and equipment required for implantation are described, as well as the equipment and methods for performing awake CEI in several animals at a time. The ability of this system to control the level of IOP is demonstrated by TonoLab measurement, and by comparing reservoir (Pinport) pressures to direct measurement using an independent anterior chamber cannula and transducer. We also demonstrate that IOP elevation can be maintained over several hours. Specific pitfalls during and after surgical implantation are highlighted to help other researchers adopt these techniques.
有助于我们理解眼内压（IOP）升高如何导致轴突损伤的动物模型将带来新的青光眼治疗方法。由于在慢性模型中难以获得可靠的测量结果，我们开发了眼内压控制升高（CEI）方法。在此方法中，将连接到升高的平衡盐溶液（BSS）储液器的套管插入麻醉的挪威棕色大鼠的前房。通过调节储液器高度来控制眼内压暴露的程度和持续时间。我们现在描述一种在清醒动物中创建CEI的方法。对具有可重复穿透的硅胶塞的Pinport进行改装，将其连接到颅骨，并连接到植入后房的微套管。为了升高眼内压，使来自储液器的BSS流经压力传感器，再流到旋转安装的系绳和注射器。将注射器放置在Pinport上，从而在CEI过程中无需进行前房插管和全身麻醉。描述了植入所需的手术技术和设备，以及一次在几只动物中进行清醒CEI的设备和方法。通过TonoLab测量，并通过将储液器（Pinport）压力与使用独立的前房套管和传感器进行的直接测量进行比较，证明了该系统控制眼内压水平的能力。我们还证明眼内压升高可以维持数小时。强调了手术植入过程中和植入后的特定陷阱，以帮助其他研究人员采用这些技术。
