Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.
Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
Invest Ophthalmol Vis Sci. 2020 Aug 3;61(10):16. doi: 10.1167/iovs.61.10.16.
To evaluate the short-term changes in inner retinal function using the photopic negative response (PhNR) after intraocular pressure (IOP) reduction in glaucoma.
Forty-seven participants with glaucoma who were commencing a new or additional IOP-lowering therapy (treatment group) and 39 participants with stable glaucoma (control group) were recruited. IOP, visual field, retinal nerve fiber layer thickness, and electroretinograms (ERGs) were recorded at baseline and at a follow-up visit (3 ± 2 months). An optimized protocol developed for a portable ERG device was used to record the PhNR. The PhNR saturated amplitude (Vmax), Vmax ratio, semi-saturation constant (K), and slope of the Naka-Rushton function were analyzed.
A significant percentage reduction in IOP was observed in the treatment group (28 ± 3%) compared to the control group (2 ± 3%; P < 0.0001). For PhNR Vmax, there was no significant interaction (F1,83 = 2.099, P = 0.15), but there was a significant difference between the two time points (F1,83 = 5.689, P = 0.019). Post hoc analysis showed a significant difference between baseline and 3 months in the treatment group (mean difference, 1.23 µV; 95% confidence interval [CI], 0.24-2.22) but not in the control group (0.30 µV; 95% CI, 0.78-1.38). K and slope were not significantly different in either group. Improvement beyond test-retest variability was seen in 17% of participants in the treatment group compared to 3% in the control group (P = 0.007, χ2 test).
The optimized protocol for measuring the PhNR detected short-term improvements in a proportion of participants following IOP reduction, although the majority showed no change.
评估青光眼患者在降低眼内压（IOP）后，利用光峰负反应（PhNR）评估内视网膜功能的短期变化。
招募了 47 名开始新的或额外的 IOP 降低治疗（治疗组）的青光眼患者和 39 名稳定青光眼患者（对照组）。在基线和随访（3±2 个月）时记录眼压、视野、视网膜神经纤维层厚度和视网膜电图（ERG）。使用便携式 ERG 设备开发的优化方案记录 PhNR。分析 PhNR 饱和振幅（Vmax）、Vmax 比、半饱和常数（K）和 Naka-Rushton 函数斜率。
与对照组（2±3%；P<0.0001）相比，治疗组（28±3%）的 IOP 显著降低。对于 PhNR Vmax，没有显著的交互作用（F1,83=2.099，P=0.15），但两个时间点之间有显著差异（F1,83=5.689，P=0.019）。事后分析显示，治疗组在基线和 3 个月时差异显著（平均差异，1.23µV；95%置信区间[CI]，0.24-2.22），而对照组无差异（0.30µV；95%CI，0.78-1.38）。两组的 K 和斜率均无显著差异。治疗组有 17%的患者改善超过了测试-重测变异性，而对照组只有 3%（P=0.007，卡方检验）。
该方案可检测到一部分患者在降低 IOP 后短期内的 PhNR 改善，尽管大多数患者没有变化。
