Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States.
Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
Invest Ophthalmol Vis Sci. 2019 Sep 3;60(12):3830-3834. doi: 10.1167/iovs.19-27758.
To compare the effects of both injectable anesthesia (ketamine/dexmedetomidine versus ketamine/xylazine) and inhalant anesthesia (isoflurane) on IOP using continuous, bilateral IOP telemetry in nonhuman primates (NHP).
Bilateral IOP was recorded continuously using a proven implantable telemetry system in five different sessions at least 2 weeks apart in four male rhesus macaques under two conditions: ketamine (3 mg/kg) with dexmedetomidine (50 μg/kg) or ketamine with xylazine (0.5 mg/kg) for induction, both followed by isoflurane for maintenance. IOP transducers were calibrated via anterior chamber manometry. Bilateral IOP was averaged over 2 minutes after injectable anesthetic induction and again after isoflurane inhalant had stabilized the anesthetic plane, then compared to baseline IOP measurements acquired immediately prior to anesthesia (both before and after initial human contact).
When compared to pre-contact baseline measurements, ketamine/dexmedetomidine injectable anesthesia lowers IOP by 1.5 mm Hg on average (P < 0.05), but IOP did not change with ketamine/xylazine anesthesia. IOP returned to baseline levels shortly after isoflurane gas anesthesia was initiated. However, injectable anesthesia lowered IOP by an average of 5.4 mm Hg when compared to that measured after initial human contact (P < 0.01).
Anesthetic effects on IOP are generally small when compared to precontact baseline but much larger when compared to IOP measures taken after human contact, indicating that IOP is temporarily elevated due to acute stress (similar to a "white coat effect") and then decreased with anesthetic relaxation. Anesthetic induction with ketamine/xylazine and maintenance with isoflurane gas should be used when IOP is measured postanesthesia.
通过非人类灵长类动物（NHP）连续双侧眼压遥测，比较注射麻醉（氯胺酮/右美托咪定与氯胺酮/二甲噻嗪）和吸入麻醉（异氟烷）对眼压的影响。
在两种条件下，通过一种已证实的植入式遥测系统，在 4 只雄性恒河猴中，至少相隔 2 周进行 5 次不同的实验，记录双侧眼压的连续变化。这两种条件分别为：氯胺酮（3mg/kg）联合右美托咪定（50μg/kg）或氯胺酮联合二甲噻嗪（0.5mg/kg）诱导，随后均使用异氟烷维持麻醉。眼压传感器通过前房测压进行校准。在注射麻醉诱导后 2 分钟和异氟烷吸入稳定麻醉平面后，测量双侧眼压，然后与麻醉前（麻醉前和首次与人接触后）的基础眼压测量值进行比较。
与接触前的基础测量值相比，氯胺酮/右美托咪定注射麻醉平均使眼压降低 1.5mmHg（P<0.05），但氯胺酮/二甲噻嗪麻醉时眼压没有变化。异氟烷气体麻醉开始后，眼压很快恢复到基线水平。然而，与首次与人接触后测量的眼压相比，注射麻醉平均使眼压降低了 5.4mmHg（P<0.01）。
与接触前的基础眼压相比，麻醉对眼压的影响通常较小，但与与人接触后测量的眼压相比，影响要大得多，这表明眼压因急性应激而暂时升高（类似于“白大衣效应”），然后随着麻醉放松而降低。测量麻醉后眼压时，应使用氯胺酮/二甲噻嗪诱导麻醉，异氟烷维持麻醉。
