Ocular Science Department, Toxikon Corporation, Bedford, MA 01730, USA.
Front Med. 2013 Sep;7(3):367-77. doi: 10.1007/s11684-013-0266-2. Epub 2013 Jun 6.
This study aimed to modify a chronic ocular hypertension (OHT) rat model to screen for potential compounds to protect retinal ganglion cells (RGCs) from responding to increased intraocular pressure (IOP). A total of 266 rats were prepared and randomly grouped according to different time-points, namely, weeks 3, 8, 16, and 24. Rats were sedated and eye examination was performed to score as the corneal damage on a scale of 1 to 4. The OHT rat model was created via the injection of a hypertonic saline solution into the episcleral veins once weekly for two weeks. OHT was identified when the IOP at week 0 was [Symbol: see text] 6 mmHg than that at week -2 for the same eye. Viable RGCs were labeled by injecting 4% FluoroGold. Rats were sacrificed, and the eyes were enucleated and fixed. The fixed retinas were dissected to prepare flat whole-mounts. The viable RGCs were visualized and imaged. The IOP (mean ± SD) was calculated, and data were analyzed by the paired t-test and one-way ANOVA. The OHT model was created in 234 of 266 rats (87.97%), whereas 32 rats (12.03%) were removed from the study because of the absence of IOP elevation (11.28%) and/or corneal damage scores over 4 (0.75%). IOP was elevated by as much as 81.35% for 24 weeks. The average IOP was (16.68 ± 0.98) mmHg in non-OHT eyes (n = 234), but was (27.95 ± 0.97) mmHg in OHTeyes (n = 234). Viable RGCs in the OHT eyes were significantly decreased in a time-dependent manner by 29.41%, 38.24%, 55.32%, and 59.30% at weeks 3, 8, 16, and 24, respectively, as compared to viable RGCs in the non-OHT eyes (P < 0.05). The OHT model was successfully created in 88% of the rats. The IOP in the OHT eyes was elevated by approximately 81% for 24 weeks. The number of viable RGCs was decreased by 59% of the rats in a time-dependent manner. The modified OHT model may provide an effective and reliable method for screening drugs to protect RGCs from glaucoma.
本研究旨在改良慢性眼高压（OHT）大鼠模型，以筛选潜在的化合物来保护视网膜神经节细胞（RGCs）免受眼内压（IOP）升高的影响。总共准备了 266 只大鼠，并根据不同的时间点（3、8、16 和 24 周）进行随机分组。大鼠被镇静，并进行眼部检查，以角膜损伤评分 1 至 4 级进行评分。通过每周向巩膜静脉注射高渗盐水两次来建立 OHT 大鼠模型，持续两周。当同一眼的 IOP 在第 0 周时比第-2 周升高[符号：见正文]6mmHg 时，即可确定发生 OHT。通过注射 4%氟金来标记存活的 RGCs。大鼠被处死，眼球被取出并固定。固定的视网膜被解剖以制备平展的全层。可见存活的 RGCs 并对其进行成像。计算 IOP（平均值 ± SD），并通过配对 t 检验和单因素方差分析对数据进行分析。在 266 只大鼠中，有 234 只（87.97%）成功建立了 OHT 模型，而 32 只（12.03%）大鼠由于 IOP 升高（11.28%）和/或角膜损伤评分超过 4（0.75%）而被排除在研究之外。IOP 升高了 24 周，最高可达 81.35%。非 OHT 眼（n=234）的平均 IOP 为（16.68±0.98）mmHg，而 OHT 眼（n=234）的平均 IOP 为（27.95±0.97）mmHg。与非 OHT 眼相比，OHT 眼的存活 RGCs 在第 3、8、16 和 24 周时分别以 29.41%、38.24%、55.32%和 59.30%的时间依赖性方式显著减少（P<0.05）。88%的大鼠成功建立了 OHT 模型。OHT 眼的 IOP 在 24 周内升高了约 81%。存活 RGCs 的数量在 24 周内以时间依赖性方式减少了 59%。改良的 OHT 模型可能为筛选保护 RGCs 免受青光眼影响的药物提供一种有效可靠的方法。
