Department of Ophthalmology, University of Basel, Basel, Switzerland.
Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.
Graefes Arch Clin Exp Ophthalmol. 2020 Jan;258(1):79-87. doi: 10.1007/s00417-019-04522-9. Epub 2019 Nov 12.
Transcorneal electrical stimulation (TES) is a novel treatment approach for patients with retinitis pigmentosa (RP). With progression of RP, loss of photoreceptors leads to less oxygen consumption and lower demand in the retina. Retinal oximetry (RO), as a non-invasive method to analyse oxygen saturation in retinal vessels, promises to be a useful therapy monitoring tool. The aim of our study was to observe changes in RO that would be attributed to therapeutic intervention.
A total of 43 eyes of 22 subjects (11♀ 11♂) suffering from RP were examined at baseline, after the first stimulation, 1 week and 6 months after TES (OkuStim®). Stimulation was performed for 30 min weekly at 200% of the individual phosphene threshold, simultaneously on both eyes. The oxygen saturation was examined at baseline and following TES stimulation with the oxygen saturation tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). The global oxygen saturation parameters (in %), within 1.0-1.5 optic disc diameters from the disc margin, in retinal arterioles (A-SO) and venules (V-SO) were estimated and their difference (A-V SO) was calculated. In addition, we evaluated the diameters (in μm) in the corresponding arterioles (D-A) and venules (D-V). ANOVA-based linear mixed-effects models were calculated with SPSS®.
Six months after TES treatment, the mean A-SO increased (from 96.48 ± 12.27 to 100.15 ± 5.56%, p = 0.09), while the V-SO decreased (from 61.61 ± 12.78 to 59.79 ± 11.15%, p = 0.48). The A-V SO, which represents the oxygen consumption of the retina, showed a statistically significant increase from 34.87 ± 9.38% at baseline to 41.36 ± 9.18% after 6 months (p = 0.02). TES had no influence on the D-A and D-V (p > 0.6).
These data indicate that TES therapy in RP leads to an increased oxygen consumption of the retina. RO may thus serve as a sensitive monitoring method for TES therapy in RP.
经角膜电刺激（TES）是一种治疗色素性视网膜炎（RP）患者的新方法。随着 RP 的发展，光感受器的丧失导致视网膜耗氧量和需求降低。视网膜血氧测定法（RO）作为一种分析视网膜血管氧饱和度的非侵入性方法，有望成为一种有用的治疗监测工具。我们的研究目的是观察治疗干预引起的 RO 变化。
共检查了 22 名患者（11 名女性，11 名男性）的 43 只眼，这些患者在基线时、第一次刺激后、TES（OkuStim®）后 1 周和 6 个月进行了检查。每周以个体闪光阈值的 200%对双眼同时进行 30 分钟的刺激。使用视网膜血管分析仪（RVA；IMEDOS Systems UG，耶拿，德国）的氧饱和度工具，在基线和 TES 刺激后检查氧饱和度。在距视盘边缘 1.0-1.5 视盘直径范围内，评估视网膜小动脉（A-SO）和小静脉（V-SO）的全球氧饱和度参数（以%表示），并计算其差异（A-V SO）。此外，我们评估了相应小动脉（D-A）和小静脉（D-V）的直径（以μm 表示）。使用 SPSS®计算基于方差分析的线性混合效应模型。
TES 治疗 6 个月后，平均 A-SO 增加（从 96.48±12.27 增加到 100.15±5.56%，p=0.09），而 V-SO 降低（从 61.61±12.78 减少到 59.79±11.15%，p=0.48）。A-V SO 代表视网膜的耗氧量，从基线时的 34.87±9.38%增加到 6 个月时的 41.36±9.18%，具有统计学意义（p=0.02）。TES 对 D-A 和 D-V 没有影响（p>0.6）。
这些数据表明，TES 治疗 RP 可导致视网膜耗氧量增加。因此，RO 可能成为 RP TES 治疗的敏感监测方法。
