Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5731-8. doi: 10.1167/iovs.10-5666. Epub 2010 Aug 18.
Vitrectomy, when followed by cataract surgery, increases the risk of open-angle glaucoma. This study was conducted in patients to determine whether these procedures are associated with increased exposure of the trabecular meshwork to oxygen.
Oxygen distribution was recorded with a fiberoptic probe in patients undergoing surgery for cataract, glaucoma, or retinal disease. pO(2) was measured beneath the central cornea, in the mid-anterior chamber, and in the anterior chamber angle. In patients who were pseudophakic or were scheduled for cataract extraction, pO(2) was also measured in the posterior chamber and near the lens.
Eyes with no previous cataract or vitrectomy surgery had steep oxygen gradients in the aqueous humor between the cornea and lens. pO(2) was low in the posterior chamber and near the lens. Previous vitrectomy was associated with significantly increased pO(2) in the posterior chamber. Eyes with previous cataract surgery had significantly elevated pO(2) only in the posterior chamber and in front of the intraocular lens (IOL). Eyes that had both vitrectomy and previous cataract surgery had increased pO(2) in the posterior chamber, anterior to the IOL, and in the anterior chamber angle. pO(2) in the posterior chamber and the anterior chamber angle correlated strongly.
Oxygen metabolism by the lens and cornea establishes oxygen gradients in the anterior segment. Vitrectomy and cataract surgery increase pO(2) in the anterior chamber angle, potentially damaging trabecular meshwork cells. We propose that oxygen levels in the anterior chamber angle are strongly influenced by oxygen derived from the ciliary body circulation.
玻璃体切除术联合白内障手术会增加开角型青光眼的风险。本研究旨在通过观察患者房水中氧的分布，确定这些手术是否会增加房角小梁网暴露于氧的风险。
使用光纤探头记录行白内障、青光眼或视网膜疾病手术患者的氧分布。测量中央角膜、前房中部和前房角下的 pO2。对于已经行白内障超声乳化手术或计划行白内障手术的患者，还测量后房和晶状体附近的 pO2。
没有白内障或玻璃体切除术病史的眼，房水中的氧在角膜和晶状体之间存在明显的浓度梯度。后房和晶状体附近的 pO2 较低。玻璃体切除术与后房内 pO2 显著升高相关。白内障手术患者仅在后房和人工晶状体（IOL）前有明显升高的 pO2。既有玻璃体切除术又有白内障手术的眼，后房、IOL 前和房角内的 pO2 均升高。后房内 pO2 和房角 pO2 之间有很强的相关性。
晶状体和角膜的氧代谢在前节建立了氧浓度梯度。玻璃体切除术和白内障手术增加了房角小梁网的 pO2，可能会损害小梁网细胞。我们推测，房角内的氧水平强烈受到睫状体循环氧的影响。
