Chu Nathan, Brambilla Enrico, Yoo Paul, Ferguson Tanner J
Equinox Ophthalmic, Inc., Newport Beach, CA, USA.
Cole Eye Institute, Cleveland Clinic, 9500 Euclid Ave., Mail code: i-13, Cleveland, OH 44195, USA.
Ther Adv Ophthalmol. 2020 Nov 18;12:2515841420971406. doi: 10.1177/2515841420971406. eCollection 2020 Jan-Dec.
A new glaucoma treatment device, known as the multi-pressure dial (MPD), has been introduced, which offers a novel approach to IOP reduction by delivering negative pressure to the periocular region. Clinical studies have demonstrated the IOP-lowering effect of the MPD via direct measurements using pneumatonometry. It remains unclear whether the eyelids, when closed, affect the transmission of negative pressure and subsequently affect IOP reduction. This study aimed to evaluate whether the transfer of negative pressure and subsequent decrease in IOP are altered by the presence of synthetic eyelid tissue.
A model with 13 different configurations controlling for eyelid material type, presence of slit/opening, and eyelid-cornea contact was employed. The slit modification was employed to mimic the physiologic separation that exists between the eyelids. Baseline IOP within an eye model was set at various levels ranging from 10 to 30 mmHg with applied negative pressure settings of 10, 15, and 20 mmHg utilized at each baseline IOP. The percentage of vacuum transfer was calculated by comparing baseline IOP to resultant IOP measurements following application of vacuum to the system.
In the open configuration (without eyelid tissue), the mean % vacuum transfer was 98.7%. The sealed, full-contact configurations exhibited values of 97.4%, 98.8%, and 97.2%. The slit configurations, which closely mimic the physiologic eyelid, demonstrated a mean % vacuum transfer of 98.7% across all settings.
The impact of eyelid tissue on transfer of negative pressure can be isolated and evaluated. The presence of eyelid tissue has an insignificant impact on the transfer of negative pressure, and the IOP reduction achievable with the MPD would not be altered with the eyelids closed.
一种名为多压力拨盘（MPD）的新型青光眼治疗设备已被引入，它通过向眼周区域施加负压提供了一种降低眼压的新方法。临床研究已通过使用眼压计直接测量证明了MPD的降眼压效果。尚不清楚眼睑闭合时是否会影响负压传递并进而影响眼压降低。本研究旨在评估合成眼睑组织的存在是否会改变负压传递及随后的眼压降低。
采用一个具有13种不同配置的模型，控制眼睑材料类型、是否存在缝隙/开口以及眼睑与角膜的接触情况。采用缝隙修改来模拟眼睑之间存在的生理分离。眼模型内的基线眼压设定在10至30 mmHg的不同水平，在每个基线眼压下使用10、15和20 mmHg的负压设置。通过比较基线眼压与对系统施加真空后得到的眼压测量值来计算真空传递百分比。
在开放配置（无眼睑组织）中，平均真空传递百分比为98.7%。密封的全接触配置显示的值分别为97.4%、98.8%和97.2%。紧密模拟生理眼睑的缝隙配置在所有设置下的平均真空传递百分比为98.7%。
眼睑组织对负压传递的影响可以被分离和评估。眼睑组织的存在对负压传递的影响微不足道，并且MPD在眼睑闭合时可实现的眼压降低不会改变。
