Factors Affecting Perceptual Threshold in Argus II Retinal Prosthesis Subjects
Factors Affecting Perceptual Threshold in Argus II Retinal Prosthesis Subjects
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DOI：
10.1167/tvst.2.4.1
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发表时间：
2013-04-01
影响因子：
3
通讯作者：
daCruz, L.
中科院分区：
文献类型：
--
作者：
Ahuja, A. K.;Yeoh, J.;daCruz, L.
目的：Argus II视网膜前膜假体的开发旨在为因外部视网膜退行性疾病而失明的受试者提供部分视力恢复。在美国和欧洲的一项单组、前瞻性、多中心临床试验中，参与者通过手术植入了该系统。本调查的目的是确定哪些因素影响电阈值，以通知手术放置的device.Methods：电极视网膜和电极中心凹的距离，分别使用SD-OCT和眼底照相确定。使用定制开发的软件测量电极对电刺激的感知阈值，其中改变电流幅度直到找到阈值。使用Espion D-FST测试测量全场刺激光阈值。电阈值和这三个解释变量（电极-视网膜距离，电极-中心凹距离，单眼光阈值）之间的关系进行了定量使用regression.Results：回归分析显示，电阈值和电极-视网膜距离之间的显着相关性（R-2 = 0.50，P = 0.0002; n = 703个电极）。90.3%与黄斑接触的电极（n = 207）在电荷密度小于1 mC/cm（2）/相位时引发感知。这些阈值数据也与神经节细胞密度分布相关（P = 0.03）。光阈值与电阈值呈弱负相关（R-2 < 0.52，P = 0.01）。多变量模型分析表明，电极-视网膜距离和光阈值对电极阈值有很高的预测性（R-2 = 0.87; P < 0.0005）。结论：综合考虑，这些结果表明，虽然光阈值应用于告知患者选择，但阵列的黄斑接触是最重要的。报告的Argus II临床研究结果与之前的体外和体内研究一致，并支持开发采用较小直径电极的高密度系统。（临床试验。政府标识符：NCT 00407602）
Purpose: The Argus II epiretinal prosthesis has been developed to provide partial restoration of vision to subjects blinded from outer retinal degenerative disease. Participants were surgically implanted with the system in the United States and Europe in a single arm, prospective, multicenter clinical trial. The purpose of this investigation was to determine which factors affect electrical thresholds in order to inform surgical placement of the device.Methods: Electrode-retina and electrode-fovea distances were determined using SD-OCT and fundus photography, respectively. Perceptual threshold to electrical stimulation of electrodes was measured using custom developed software, in which current amplitude was varied until the threshold was found. Full field stimulus light threshold was measured using the Espion D-FST test. Relationships between electrical threshold and these three explanatory variables (electrode-retina distance, electrode-fovea distance, and monocular light threshold) were quantified using regression.Results: Regression analysis showed a significant correlation between electrical threshold and electrode-retina distance (R-2 = 0.50, P = 0.0002; n = 703 electrodes). 90.3% of electrodes in contact with the macula (n = 207) elicited percepts at charge densities less than 1 mC/cm(2)/phase. These threshold data also correlated well with ganglion cell density profile (P = 0.03). A weaker, but still significant, inverse correlation was found between light threshold and electrical threshold (R-2 < 0.52, P = 0.01). Multivariate modeling indicated that electrode-retina distance and light threshold are highly predictive of electrode threshold (R-2 = 0.87; P < 0.0005).Conclusions: Taken together, these results suggest that while light threshold should be used to inform patient selection, macular contact of the array is paramount.Translational Relevance: Reported Argus II clinical study results are in good agreement with prior in vitro and in vivo studies, and support the development of higher-density systems that employ smaller diameter electrodes. (clinicaltrials. gov identifier: NCT00407602)