Liu Hsin-Hua, Bui Bang V, Nguyen Christine T O, Kezic Jelena M, Vingrys Algis J, He Zheng
Department of Optometry and Vision Sciences University of Melbourne, Parkville, Victoria, Australia.
Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
Invest Ophthalmol Vis Sci. 2015 May;56(5):2811-20. doi: 10.1167/iovs.14-16009.
To induce chronic intraocular pressure (IOP) elevation in rat eyes by circumlimbal suture.
Anesthetized (isoflurane) Long-Evans rats underwent unilateral circumlimbal suture implantation while the fellow eyes served as untreated controls (n = 15). A sham group (n = 8) received the same procedure except that the suture was loosely tied. Intraocular pressure, electroretinography (ERG), and optical coherence tomography (OCT) were monitored for 15 weeks, after which retinal histology and immunofluorescence staining for glial fibrillary acidic protein (GFAP) and ionized calcium binding adapter molecule-1 (Iba-1) were undertaken.
Both IOP and ERG remained unaltered in the sham and all control eyes over 15 weeks. In the ocular hypertensive eye, IOP spiked from 17 ± 1 to 58 ± 3 mm Hg immediately after suture application, recovering to 32 ± 2 mm Hg by 24 hours, and remained elevated by 7 to 10 mm Hg above baseline for 15 weeks. At week 2, there was a small reduction of ERG components involving the photoreceptor a-wave, bipolar cell b-wave, and ganglion cell-mediated scotopic threshold response (pSTR). The reduction in a- and b-wave remained stable, while the pSTR became more affected from week 8 onward (P < 0.05). By week 12, there was progressive retinal nerve fiber layer (RNFL) thinning. At week 15, GFAP expression was upregulated in inner retina and on Müller cells. The ganglion cell dysfunction was associated with RNFL thinning and cell loss in the ganglion cell layer.
Circumlimbal suture provides a simple and cost-effective way to induce mild chronic ocular hypertension in rat eyes. This model produces preferential ganglion cell dysfunction and RNFL reduction.
通过角膜缘缝线法诱导大鼠眼内慢性眼压升高。
对麻醉（异氟烷）的Long-Evans大鼠进行单侧角膜缘缝线植入，对侧眼作为未处理的对照（n = 15）。假手术组（n = 8）接受相同手术，但缝线系得较松。监测眼压、视网膜电图（ERG）和光学相干断层扫描（OCT）15周，之后进行视网膜组织学检查以及针对胶质纤维酸性蛋白（GFAP）和离子钙结合衔接分子1（Iba-1）的免疫荧光染色。
在15周内，假手术组和所有对照眼的眼压和ERG均未改变。在高眼压眼中，缝线应用后眼压立即从17±1毫米汞柱飙升至58±3毫米汞柱，24小时后恢复至32±2毫米汞柱，并在15周内比基线水平升高7至10毫米汞柱。在第2周，涉及光感受器a波、双极细胞b波和神经节细胞介导的暗视阈值反应（pSTR）的ERG成分略有降低。a波和b波的降低保持稳定，而pSTR从第8周起受影响更大（P<0.05）。到第12周，视网膜神经纤维层（RNFL）逐渐变薄。在第15周，GFAP在内层视网膜和Müller细胞上的表达上调。神经节细胞功能障碍与RNFL变薄以及神经节细胞层中的细胞丢失有关。
角膜缘缝线法为诱导大鼠眼内轻度慢性高眼压提供了一种简单且经济有效的方法。该模型产生了优先的神经节细胞功能障碍和RNFL减少。
