Meral Nesrin, Zabek Olga, Camenzind Zuche Hanna, Müller Ursula, Prétot Dominique, Rickmann Annekatrin, Scholl Hendrik P N, Della Volpe Waizel Maria
Department of Ophthalmology, University of Basel, Basel, Switzerland.
Department of Ophthalmology, University of Basel, Basel, Switzerland,
Ophthalmic Res. 2022;65(1):52-59. doi: 10.1159/000519998. Epub 2021 Oct 4.
Transcorneal electrical stimulation (TES) is a new therapeutical approach for retinitis pigmentosa (RP). With progression of RP, degeneration of photoreceptors results in lower oxygen consumption of the retina. Retinal oximetry (RO) is a noninvasive method to analyze oxygen saturation in retinal vessels and has shown promising short-term results as a therapy monitoring tool for TES. The aim of our study was to measure the long-term effects of TES on RO parameters over a period of 3 years (3Y).
A total of 18 eyes of 9 subjects (5♀ 4♂) suffering from RP were examined at baseline (BL), 6 months, and 3Y of TES (OkuStim®) treatment. TES was performed for 30 min once a week at 200% of the individual phosphene threshold simultaneously on both eyes. The oxygen saturation was examined at BL and following TES therapy with the oxygen saturation tool of the Retinal Vessel Analyser (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-SO2) and venules (V SO2) were measured and their difference (A-V SO2) was calculated. In addition, we recorded the diameters in the main arterioles (D-A) and venules (D-V). ANOVA-based linear mixed-effects models were employed for statistical analysis using SPSS®.
After 3Y of TES treatment both the mean A-SO2 (from 96.35 ± 12.76% to 100.89 ± 5.87%, p = 0.22) and V SO2 (from 62.20 ± 11.55% to 64.55 ± 8.24%, p = 0.77) increased slightly. The A-V SO2, which corresponds to the oxygen consumption of the retina, presented also with a slight increment from 34.15 ± 9.68% at BL to 36.23 ± 7.71% without reaching statistical significance (p = 0.27). TES also did not appear to alter the vascular diameter parameters, D-A and D-V (p > 0.05).
Our long-term observations indicate that TES therapy in RP might lead to a slight increment in oxygen consumption of the retina. However, a larger cohort and longer duration may be needed to adequately power a follow-up study and to confirm this trend reflecting a possible benefit of TES for RP.
经角膜电刺激(TES)是一种用于治疗视网膜色素变性(RP)的新方法。随着RP的进展,光感受器退化导致视网膜氧消耗降低。视网膜血氧测定法(RO)是一种分析视网膜血管中氧饱和度的非侵入性方法,作为TES的治疗监测工具已显示出有前景的短期结果。我们研究的目的是测量TES在3年期间对RO参数的长期影响。
对9名患有RP的受试者(5名女性,4名男性)的18只眼睛在基线(BL)、6个月和TES(OkuStim®)治疗3年时进行检查。TES每周进行一次,每次30分钟,在两只眼睛上同时以个体光幻视阈值的200%进行。在BL和TES治疗后,使用视网膜血管分析仪(IMEDOS Systems UG,德国耶拿)的氧饱和度工具检查氧饱和度。测量距视盘边缘1.0 - 1.5视盘直径范围内视网膜小动脉(A - SO2)和小静脉(V - SO2)的全局氧饱和度参数(以%为单位),并计算它们的差值(A - V - SO2)。此外,我们记录了主要小动脉(D - A)和小静脉(D - V)的直径。使用SPSS®基于方差分析的线性混合效应模型进行统计分析。
TES治疗3年后,平均A - SO2(从96.35±12.76%增至100.89±5.87%,p = 0.22)和V - SO2(从62.20±11.55%增至64.55±8.24%,p = 0.77)均略有增加。对应于视网膜氧消耗的A - V - SO2也略有增加,从BL时的34.15±9.68%增至36.23±7.71%,但未达到统计学显著性(p = 0.27)。TES似乎也未改变血管直径参数D - A和D - V(p > 0.05)。
我们的长期观察表明,RP中的TES治疗可能会导致视网膜氧消耗略有增加。然而,可能需要更大的队列和更长的持续时间来为后续研究提供足够的效力,并确认这一趋势反映了TES对RP可能的益处。