Wilson C A, Benner J D, Berkowitz B A, Chapman C B, Peshock R M
Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas.
Arch Ophthalmol. 1994 Jun;112(6):839-45. doi: 10.1001/archopht.1994.01090180139048.
Transcorneal oxygenation is a promising approach to the treatment of various anterior ocular diseases, but its effect on the vitreous and retina is uncertain. The purpose of this study was to evaluate the ocular conditions necessary to permit transcorneal oxygenation of the preretinal vitreous in the rabbit eye.
Oxygen at atmospheric pressure was supplied via a goggle to the eye while preretinal oxygen tensions were measured with a minimally invasive technique: fluorine-19 (19F) nuclear magnetic resonance spectroscopy of a small preretinal droplet of perfluorotributylamine. Experiments were performed on lensectomized eyes with intact posterior lens capsules (group 1) or in eyes that had also undergone posterior capsular discission (group 2) and mechanical vitrectomy (group 3). To better understand the results of the oxygenation studies, a water-soluble, freely diffusible contrast agent was applied topically to the cornea, and its penetration into the aqueous and vitreous was studied using T1-weighted magnetic resonance imaging.
Preretinal PO2 was significantly increased after 30 minutes of transcorneal oxygenation in group 3 eyes (P = .002). In contrast, no change was observed in the other groups despite 30 minutes (group 1) or 3 hours (group 2) of oxygen exposure. The imaging studies demonstrated that contrast penetration of the vitreous was uniform and rapid in eyes in group 3, consistent with a fluid flow-dominated process. A much slower process of anterior and midvitreous enhancement was observed in groups 1 and 2 that was consistent with contrast diffusion.
Because of bulk fluid movement, transcorneal oxygenation of the retina is feasible in single-compartment (vitrectomized, lensectomized) eyes within a reasonable period (30 minutes). This finding could prove useful in the treatment of retinal diseases in which hypoxia may play a role.
经角膜氧合是治疗各种眼前段疾病的一种有前景的方法，但其对玻璃体和视网膜的影响尚不确定。本研究的目的是评估在兔眼中实现视网膜前玻璃体经角膜氧合所需的眼部条件。
通过护目镜向眼睛供应常压氧气，同时采用微创技术测量视网膜前氧张力：对一小滴视网膜前全氟三丁胺进行氟 - 19（¹⁹F）核磁共振波谱分析。实验在晶状体切除且后囊完整的眼睛（第1组）、同时进行了后囊切开的眼睛（第2组）以及进行了机械玻璃体切除术的眼睛（第3组）上进行。为了更好地理解氧合研究的结果，将一种水溶性、可自由扩散的造影剂局部应用于角膜，并使用T1加权磁共振成像研究其在房水和玻璃体中的渗透情况。
第3组眼睛经角膜氧合30分钟后，视网膜前PO₂显著升高（P = 0.002）。相比之下，尽管第1组暴露氧气30分钟、第2组暴露3小时，但其他组未观察到变化。成像研究表明，第3组眼睛中玻璃体的造影剂渗透均匀且迅速，这与以流体流动为主导的过程一致。在第1组和第2组中观察到前玻璃体和中玻璃体增强过程要慢得多，这与造影剂扩散一致。
由于大量液体流动，在单腔（玻璃体切除、晶状体切除）眼中，在合理时间（30分钟）内实现视网膜经角膜氧合是可行的。这一发现可能对治疗缺氧可能起作用的视网膜疾病有用。
