Peyman G, Chow A Y, Liang C, Chow V Y, Perlman J I, Peachey N S
LSU Eye Center, New Orleans, USA.
Ophthalmic Surg Lasers. 1998 Mar;29(3):234-41.
To examine the function of a semiconductor microphotodiode array (SMA) surgically implanted in the subretinal space.
Positive-intrinsic layer-negative (PiN) or negative-intrinsic layer-positive (NiP) SMAs were surgically placed into the subretinal space of rabbits through a pars plana incision and a posterior retinotomy. The implants required no external connections for power and were sensitive to light over the visible and infrared (IR) spectrum; IR stimuli were used to isolate implant-mediated responses from the activity of native photoreceptors. A stimulator ophthalmoscope was used to superimpose IR stimuli on the implant and adjacent retinal areas, and responses were recorded during the postoperative recovery period. SMA responses were also evaluated in vitro. The animals were given lethal anesthetic overdoses, and the retinas were examined histologically.
The in vitro implant response consisted of an electrical spike, followed by a small-amplitude DC offset that followed the time course of the IR stimulation, and an overshoot at the stimulus offset. The SMAs placed in the subretinal space retained a stable position and continued to function throughout the postoperative period. The SMA responses recorded in vivo included additional slow-wave components that were absent from the in vitro recordings. These responses reverted to the in vitro configuration following the death of the animal. There was a significant loss of retinal cells in areas overlying the implant, and the retina appeared normal away from the implant and surgical site.
SMAs can be successfully implanted into the subretinal space and will generate current in response to light stimulation during an extended period of time.
研究手术植入视网膜下间隙的半导体微光电二极管阵列（SMA）的功能。
通过扁平部切口和视网膜后切开术，将正-本征层-负型（PiN）或负-本征层-正型（NiP）SMA手术植入兔的视网膜下间隙。植入物无需外部电源连接，对可见光和红外（IR）光谱范围内的光敏感；使用红外刺激来将植入物介导的反应与天然光感受器的活动区分开。使用刺激式检眼镜将红外刺激叠加在植入物和相邻视网膜区域上，并在术后恢复期记录反应。还对SMA反应进行了体外评估。对动物过量注射致死剂量的麻醉剂，然后对视网膜进行组织学检查。
体外植入物反应包括一个电脉冲，随后是一个跟随红外刺激时间进程的小幅度直流偏移，以及刺激偏移时的过冲。置于视网膜下间隙的SMA保持稳定位置，并在术后整个期间持续发挥功能。体内记录的SMA反应包括体外记录中不存在的其他慢波成分。动物死亡后，这些反应恢复为体外状态。植入物上方区域的视网膜细胞有显著损失，远离植入物和手术部位的视网膜外观正常。
SMA可成功植入视网膜下间隙，并在较长时间内对光刺激产生电流。
