Pixium Vision, Paris, France.
J Neural Eng. 2020 Jun 12;17(3):035005. doi: 10.1088/1741-2552/ab8f70.
Retinal implants have the potential to restore some sight in patients with retinal degeneration. The PRIMA implant's novel design features simpler insertion and no transscleral cabling or extraocular components. This in vitro study investigated PRIMA's durability under real time and accelerated conditions and estimated the device's lifespan in vivo.
Two potential failure modes were examined: corrosion and overstimulation. Real-time aging was tested using implants immersed in balanced saline solution (BSS) at 37 °C, mimicking the intraocular environment. Accelerated aging was examined at 77 °C (Arrhenius theory). Confirmatory testing of acceleration factor was performed using different temperatures (37 °C-87 °C) and weakened implant coatings. The effect of repeated maximum stimulation was tested using a pulsed infrared laser (6x acceleration factor). Data were used to estimate device lifespan.
175 implants were tested for up to 33 months. No corrosion or water ingress was observed after approximately 20 accelerated years. A pixel failure rate of 0.15% was recorded after 10 accelerated years' stimulation. The derived lifespan estimation for the PRIMA implant was 27.0 years with a reliability of 90% (95% confidence interval).
The PRIMA implant was found to be robust, with in vitro reliability of at least 10 years. The PRIMA implant shows durability and functionality for clinically relevant timespans under similar environmental conditions to the human eye. These results require in vivo confirmation.
视网膜植入物有潜力为视网膜变性患者恢复部分视力。PRIMA 植入物具有新颖的设计特点，插入更简单，无需经巩膜布线或额外的眼外组件。这项体外研究调查了 PRIMA 在实时和加速条件下的耐用性，并估计了该设备在体内的使用寿命。
检查了两种潜在的失效模式：腐蚀和过度刺激。通过将植入物浸入 37°C 的平衡盐溶液（BSS）中进行实时老化测试，模拟眼内环境。在 77°C 下进行加速老化测试（阿累尼乌斯理论）。使用不同的温度（37°C-87°C）和弱化的植入物涂层对加速因子的确认性测试进行了确认。使用脉冲红外激光（6 倍加速因子）测试了重复最大刺激的效果。使用这些数据来估计设备的使用寿命。
对 175 个植入物进行了长达 33 个月的测试。在大约 20 年的加速后，没有观察到腐蚀或水进入。在 10 年的加速刺激后，记录到像素故障率为 0.15%。PRIMA 植入物的寿命估计为 27.0 年，可靠性为 90%（95%置信区间）。
PRIMA 植入物被发现具有坚固性，体外可靠性至少为 10 年。在类似于人眼的环境条件下，PRIMA 植入物在临床相关时间内显示出耐用性和功能性。这些结果需要体内确认。
