Intraocular pressure (IOP) is important for eye health as abnormal levels can led to ocular tissue damage. IOP is typically estimated by tonometry, which only provides snapshots of pressure history. Tonometry also requires subject cooperation and corneal contact that may influence IOP readings. The aim of this research was to investigate IOP dynamics of conscious animals in response to stressors, common anesthetics, tonometry, and temperature manipulations. An eye of male Brown-Norway rats was implanted with a fluid-filled cannula connected to a wireless telemetry system that records IOP continuously. Stress effects were examined by restricting animal movements. Anesthetic effects were examined by varying isoflurane concentration or injecting a bolus of ketamine. Tonometry effects were examined using applanation and rebound tonometers. Temperature effects were examined by exposing anesthetized and conscious animals to warm or cool surfaces. Telemetry recordings revealed that IOP fluctuates spontaneously by several mmHg, even in idle and anesthetized animals. Environmental disturbances also caused transient IOP fluctuations that were synchronous in recorded animals and could last over a half hour. Animal immobilization produced a rapid sustained elevation of IOP that was blocked by anesthetics, whereas little-to-no IOP change was detected in isoflurane- or ketamine-anesthetized animals if body temperature (BT) was maintained. IOP and BT decreased precipitously when heat support was not provided and were highly correlated during surface temperature manipulations. Surface temperature had no impact on IOP of conscious animals. IOP increased slightly during applanation tonometry but not rebound tonometry. The results show that IOP is dynamically modulated by internal and external factors that can activate rapidly and last long beyond the initiating event. Wireless telemetry indicates that animal interaction induces startle and stress responses that raise IOP. Anesthesia blocks these responses, which allows for better tonometry estimates of resting IOP provided that BT is controlled.

眼内压 (IOP) 对眼睛健康很重要，因为异常水平会导致眼组织损伤。IOP 通常通过眼压计估计，它只提供压力历史的快照。眼压计还需要受试者合作和角膜接触，这可能会影响 IOP 读数。这项研究的目的是调查有意识的动物对压力源、普通麻醉剂、眼压测量和温度操作的反应的眼压动态。雄性布朗-挪威大鼠的一只眼睛被植入了一个充满液体的插管，该插管连接到一个无线遥测系统，该系统连续记录眼压。通过限制动物运动来检查压力效应。通过改变异氟醚浓度或注射一团氯胺酮来检查麻醉效果。使用压平和回弹眼压计检查眼压效应。通过将麻醉和有意识的动物暴露于温暖或凉爽的表面来检查温度效应。遥测记录显示，即使在闲置和麻醉的动物中，眼压也会自发波动几毫米汞柱。环境干扰还导致瞬时眼压波动，这些波动在记录的动物中是同步的，可能持续半小时以上。动物固定导致眼压快速持续升高，被麻醉剂阻断，而在保持体温 (BT) 的情况下，异氟醚或氯胺酮麻醉的动物几乎没有检测到眼压变化。当不提供热支持时，IOP 和 BT 急剧下降，并且在表面温度操作期间高度相关。表面温度对有意识动物的眼压没有影响。在压平眼压测量期间眼压略有增加，但没有回弹眼压测量。结果表明，IOP 受到内部和外部因素的动态调节，这些因素可以快速激活并持续很长时间。无线遥测表明动物互动会引起惊吓和压力反应，从而提高眼压。麻醉会阻止这些反应，如果 BT 得到控制，则可以更好地估计静息 IOP 的眼压计。