Moseley H, Foulds W S, Allan D, Kyle P M
Br J Ophthalmol. 1984 Mar;68(3):145-51. doi: 10.1136/bjo.68.3.145.
The movement of water to and from the vitreous across the retina and pigment epithelium is important in relation to an understanding of such conditions as retinal detachment and its surgical cure, central serous retinopathy, and retinal oedema. Experiments were carried out to determine the main routes for removal of water injected into the vitreous and to see if the removal could be explained on the basis of diffusion or whether bulk flow was also implicated. 25 microCi of 3H2O in 25 microliter were injected into a central position in the vitreous humour of living rabbits under general anaesthesia. For 9 animals blood was collected from one of the 4 vortex veins draining the choroid and the radioactivity in the samples measured. For another 6 rabbits similarly injected the radioactivity in samples of aqueous humour was determined. The percentage of injectate recovered from the vortex vein blood ranged between 13% and 38%, mean 25 +/- 3%. The percentage of injectate recovered from the aqueous humour ranged between 1.2% and 5.2%, mean 2.8 +/- 0.6%. Analysis of the time course of isotope activity in the samples revealed a mean transit time from the mid vitreous to the choroid of 32 +/- 2 minutes, and from the mid vitreous to the anterior chamber of 84 +/- 3 minutes. By means of a computer model it was calculated that diffusion alone could effect this transfer; if active transport were involved in the transport of 3H2O to the choroid, this was not a limiting factor under the conditions of the experiment.
水通过视网膜和色素上皮进出玻璃体的运动，对于理解诸如视网膜脱离及其手术治疗、中心性浆液性视网膜病变和视网膜水肿等病症具有重要意义。开展了实验以确定注入玻璃体的水的主要清除途径，并探究这种清除能否基于扩散来解释，或者是否也涉及大量流动。在全身麻醉下，将25微升含25微居里³H₂O的溶液注入活兔玻璃体的中央位置。对9只动物，从引流脉络膜的4条涡静脉之一采集血液并测量样本中的放射性。对另外6只同样注射的兔子，测定房水样本中的放射性。从涡静脉血液中回收的注入物百分比在13%至38%之间，平均为25±3%。从房水中回收的注入物百分比在1.2%至5.2%之间，平均为2.8±0.6%。对样本中同位素活性的时间进程分析显示，从玻璃体中部到脉络膜的平均转运时间为32±2分钟，从玻璃体中部到前房的平均转运时间为84±3分钟。通过计算机模型计算得出，仅扩散就能实现这种转运；如果³H₂O向脉络膜的转运涉及主动转运，在实验条件下这并非限制因素。
