高眼压猴视盘和视网膜神经节细胞复合体的纵向变化

Longitudinal changes in optic disc and retinal ganglion cell complex in monkeys with high intraocular pressure

目的观察高眼压前后视盘和视网膜神经节细胞复合体(ganglion cell complex,GCC)的纵向变化,探讨高眼压对视盘和GCC的影响。方法选取实验用恒河猴3只,全部为雄性,年龄4岁,保持在12 h暗和12 h光照(100 Lux)环境中给予水果、蔬菜等混合喂养。3只猴右眼用激光诱发高眼压。检测光凝前后的实验猴眼压,行眼底像和光学相干断层扫描检查。记录基线和3次随访的视盘外观、视网膜神经纤维层(retinal nerve fiber layer,RNFL)的厚度和GCC,对实验结果进行统计学分析。结果首次光凝后激光眼即刻眼压为(3.00±0.58)mmHg(1 kPa=7.5 mmHg),明显低于光凝前的眼压(17.33±1.20)mmHg和对侧眼的眼压(17.00±1.53)mmHg,差异均有统计学意义(t=16.25,P=0.004;t=9.17,P=0.010)。首次光凝后近2 a激光眼的眼压为(41.00±5.00)mmHg仍维持在高于光凝前的基线水平,差异有统计学意义(t=6.17,P=0.030)。光凝后4个月时激光眼视盘的颜色开始变淡,8个月时颜色较光凝前明显变淡,12个月时颜色仍然变淡。对侧眼视盘的颜色在光凝后4~12个月都呈现粉红色,与光凝前对比无明显变化。光凝后4个月、8个月和12个月激光眼视盘周围的RNFL厚度都较对侧眼以及光凝前变薄。对侧眼视盘周围的RNFL厚度在光凝后4个月、8个月和12个月与光凝前相比均无明显改变。光凝后4个月、8个月和12个月激光眼黄斑区GCC的厚度与光凝前和对侧眼相比变薄。光凝后4个月、8个月和12个月对侧眼黄斑区GCC的厚度与光凝前相比均无明显改变。结论在高眼压造成青光眼性视神经病变和视网膜病变之前,视盘和GCC一直处于高眼压和低眼压的波动状态;由此引起的缺血再灌注交替性损伤可能是激光诱导的高眼压模型猴的病理生理特征之一。

Objective To observe the longitudinal changes in optic disc and ganglion cell complex(GCC)in monkeys before and after high intraocular pressure(IOP).Methods Three experimental male rhesus monkeys were collected,aged 4 years,and fed with fruits and vegetables in a 12 h dark and 12 h light(100 Lux)environment.High IOP was induced by laser in each right eye of these monkeys.IOP,retinal fundus images and optical coherence tomography(OCT)were examined longitudinally before and after laser coagulation.Baseline and 3 follow-up exams of optic disc appearance,retinal nerve fiber layer(RNFL)thickness and GCC were obtained for analysis.Paired t-test was used to compare the difference of IOP between the lasered eyes and the fellow eyes.Repeated measurement of analysis of variance was adopted to calculate the differences in different time points.Results Immediate IOP was(3.00±0.58)mmHg(1 kPa=7.5 mmHg)after first laser coagulation in lasered eyes,which was lower than that before laser coagulation[(17.33±1.20)mmHg]and that of fellow eyes[(17.00±1.53)mmHg].The differences were statistically significant(t=16.25,P=0.004 and t=9.17,P=0.010).About 2 years after the first laser coagulation,the IOP of lasered eyes was(41.00±5.00)mmHg,which was still higher than the baseline before laser coagulation.The difference was statistically significant(t=6.17,P=0.030).At 4 months after laser coagulation,the color of the optic disc in the lasered eyes started to fade,the color of the optic disc showed much paler at 8 months than that before laser coagulation,and still pale at 12 months.The color of optic disc in the fellow eyes was pink at 4 to 12 months after laser coagulation,and there was no significant change compared with that before laser coagulation.At 4 months,8 months and 12 months after laser coagulation,the thickness of RNFL around the optic disc in lasered eyes was thinner than that of the fellow eyes and that before laser coagulation,but RNFL thickness around the optic disc in the fellow eyes showed no significant change compared with that before laser coagulation.At 4 months,8 months and 12 months after laser coagulation,the thickness of GCC in macular area of lasered eyes was thinner than that before laser coagulation and that of fellow eyes,while GCC thickness in the macular area of the fellow eyes showed no significant change compared with that before laser coagulation.Conclusion Alternative ischemia and reperfusion injury to the optic disc and GCC might be a pathophysiological characteristic of the primate glaucoma model induced by laser.