Experimental Ophthalmology, Department of Ophthalmology, University Medical Center, Johannes Gutenberg University, Mainz, Germany.
Curr Eye Res. 2010 Nov;35(11):1034-9. doi: 10.3109/02713683.2010.498654.
The TonoPen applanation tonometry is an established method for intraocular pressure (IOP) measurement. The IOP is one of the main variables affecting retinal ganglion cell (RGC) loss in experimental animal models in ophthalmology and the main risk factor for human glaucoma. In this study, we examined if IOP measurements with the TonoPen itself lead to retinal ganglion cell loss or any other possible retina damages, such as intraocular bleedings or ablation, in Lewis rats.
Three groups of rats (n = 5 each) were formed. IOP monitoring, using a TonoPen XL, was performed on groups 1 and 3. Animals in groups 1 and 2 received funduscopies before and after one and two weeks of the study, in order to detect possible abnormalities. After two weeks, retinal flatmounts were stained to detect ganglion cells. RGCs were manually counted in eight predefined areas to compare mean RGC densities between groups 1 and 2 (IOP readings vs. no readings), using student t-test.
No significant difference in RGC density between animals that underwent IOP readings and controls could be observed (p = 0.8). As expected, no IOP alterations were monitored in groups 1 and 3 throughout the study. No retinal abnormalities, such as bleeding or retina ablation, were detectable.
We could detect no effects on retinal ganglion cell survival in Lewis rats or any other damages to the retina caused by IOP measurements using a TonoPen XL. This study proposes that repeated applanation tonometry does not affect RGC numbers, one of the main monitored variables in most glaucoma model studies. Therefore, the use of a TonoPen XL for repeated IOP monitoring in Lewis rats can be considered harmless.
眼压（IOP）测量的托诺潘（TonoPen）压平眼压计是一种成熟的方法。IOP 是眼科实验动物模型中影响视网膜神经节细胞（RGC）损失的主要变量之一，也是人类青光眼的主要危险因素。在这项研究中，我们检查了使用 TonoPen 本身进行 IOP 测量是否会导致视网膜神经节细胞损失或任何其他可能的视网膜损伤，如眼内出血或消融，在 Lewis 大鼠中。
形成三组大鼠（每组 5 只）。使用 TonoPen XL 对第 1 组和第 3 组进行 IOP 监测。第 1 组和第 2 组的动物在研究开始前和 1 周及 2 周后进行眼底检查，以检测可能的异常。两周后，对视网膜进行扁平化染色以检测神经节细胞。使用学生 t 检验在 8 个预定义区域中手动计数 RGC，以比较第 1 组和第 2 组之间的平均 RGC 密度（IOP 读数与无读数）。
在接受 IOP 读数的动物和对照组之间，RGC 密度没有明显差异（p = 0.8）。如预期的那样，在整个研究过程中，第 1 组和第 3 组均未监测到 IOP 变化。未检测到视网膜异常，如出血或视网膜消融。
我们在 Lewis 大鼠中未发现眼压测量（使用 TonoPen XL）对视网膜神经节细胞存活或对视网膜造成任何其他损伤的影响。这项研究表明，重复压平眼压计不会影响 RGC 数量，这是大多数青光眼模型研究中主要监测的变量之一。因此，在 Lewis 大鼠中，可考虑使用 TonoPen XL 进行重复 IOP 监测是无害的。
