Tsai James C, Wu Li, Worgul Basil, Forbes Max, Cao Jingtai
Brown Glaucoma Research Laboratory, Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, USA.
Curr Eye Res. 2005 Nov;30(11):1025-31. doi: 10.1080/02713680500320729.
The aim of this pilot study was to evaluate the potential neuroprotective effect of an intravitreal injection of erythropoietin (EPO) on retinal ganglion cell (RGC) preservation in an episcleral vessel cautery-induced rat model of glaucoma.
The animals were randomly assigned into an unoperated control group (n = 11) and three experimental groups: episcleral vessel cautery only (EVC: n = 4), episcleral vessel cautery with intravitreal normal saline injection (EVC-NS; n = 5), and episcleral vessel cautery with intravitreal EPO treatment (EVC-EPO; n = 9). The intravitreal injections were limited to 5 mul containing either normal saline alone or 200 ng of EPO in normal saline administered immediately after the cautery procedure. RGCs were labeled retrogradely by FluoroGold neuron tracer 5 to 7 days prior to the collection of eyes at day 21 and counted in whole flat-mounted retinas with fluorescence microscopy.
Compared to the RGC counts in retinal specimens from unoperated control rats (12,619 +/- 310), the corresponding RGC counts were significantly decreased in both the EVC (9116 +/- 273; p < 0.005) and EVC-NS (9489 +/- 293; p < 0.005) groups but not significantly decreased in the EVC-EPO (11,212 +/- 414; p = 0.051) treated retinas.
A single intravitreal 200 ng dose of EPO appears to have a protective effect on RGC viability in an in vivo rat model of glaucoma. Further experimental studies are needed to confirm these preliminary results and to optimize the appropriate dose and frequency of EPO delivery in animal models of glaucoma.
本初步研究旨在评估玻璃体内注射促红细胞生成素（EPO）对巩膜上静脉烧灼诱导的大鼠青光眼模型中视网膜神经节细胞（RGC）保存的潜在神经保护作用。
将动物随机分为未手术对照组（n = 11）和三个实验组：仅巩膜上静脉烧灼组（EVC：n = 4）、巩膜上静脉烧灼联合玻璃体内注射生理盐水组（EVC - NS；n = 5）以及巩膜上静脉烧灼联合玻璃体内EPO治疗组（EVC - EPO；n = 9）。玻璃体内注射量限制为5微升，其中单独含有生理盐水或在烧灼术后立即给予含200纳克EPO的生理盐水。在第21天采集眼球前5至7天，用荧光金神经元示踪剂对RGC进行逆行标记，并通过荧光显微镜在整个视网膜铺片中计数。
与未手术对照大鼠视网膜标本中的RGC计数（12,619 ± 310）相比，EVC组（9116 ± 273；p < 0.005）和EVC - NS组（9489 ± 293；p < 0.005）的相应RGC计数均显著降低，但EVC - EPO治疗组视网膜（11,212 ± 414；p = 0.051）的RGC计数未显著降低。
在体内大鼠青光眼模型中，单次玻璃体内注射200纳克剂量的EPO似乎对RGC活力具有保护作用。需要进一步的实验研究来证实这些初步结果，并在青光眼动物模型中优化EPO给药的合适剂量和频率。
