Bello Simon A, Malavade Sharad, Passaglia Christopher L
Department of Chemical & Biomedical Engineering, University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA.
Department of Ophthalmology, University of South Florida, Tampa, FL, 33620, USA.
Ann Biomed Eng. 2017 Apr;45(4):990-1002. doi: 10.1007/s10439-016-1735-y. Epub 2016 Sep 27.
Animal models of ocular hypertension are important for glaucoma research but come with experimental costs. Available methods of intraocular pressure (IOP) elevation are not always successful, the amplitude and time course of IOP changes are unpredictable and irreversible, and IOP measurement by tonometry is laborious. Here we present a novel system for monitoring and controlling IOP without these limitations. It consists of a cannula implanted in the anterior chamber of the eye, a pressure sensor that continually measures IOP, and a bidirectional pump driven by control circuitry that can infuse or withdraw fluid to hold IOP at user-desired levels. A portable version was developed for tethered use on rats. We show that rat eyes can be cannulated for months without causing significant anatomical or physiological damage although the animal and its eyes freely move. We show that the system measures IOP with <0.7 mmHg resolution and <0.3 mmHg/month drift and can maintain IOP within a user-specified window of desired levels for any duration necessary. We conclude that the system is ready for cage- or bench-side applications. The results lay the foundation for an implantable version that would give glaucoma researchers unprecedented knowledge and control of IOP in rats and potentially larger animals.
高眼压动物模型对青光眼研究很重要，但会产生实验成本。现有的眼压（IOP）升高方法并不总是成功的，眼压变化的幅度和时间进程不可预测且不可逆转，并且通过眼压计测量眼压很费力。在此，我们提出一种用于监测和控制眼压的新型系统，该系统没有这些局限性。它由植入眼前房的套管、持续测量眼压的压力传感器以及由控制电路驱动的双向泵组成，该双向泵可以注入或抽出液体以将眼压维持在用户期望的水平。开发了一种便携式版本，用于在大鼠身上进行 tethered 使用。我们表明，尽管动物及其眼睛自由移动，但大鼠眼睛可以插管数月而不会造成明显的解剖学或生理学损伤。我们表明，该系统测量眼压的分辨率小于 0.7 mmHg，每月漂移小于 0.3 mmHg，并且可以在任何必要的持续时间内将眼压维持在用户指定的期望水平窗口内。我们得出结论，该系统已准备好用于笼侧或台面应用。这些结果为可植入版本奠定了基础，该版本将为青光眼研究人员提供关于大鼠及可能更大动物眼压的前所未有的知识和控制能力。
