Safety and efficacy of explanting or replacing suprachoroidal electrode arrays in a feline model.

摘要: Background A key requirement for retinal prostheses is the ability safe removal or replacement. We examined whether suprachoroidal electrode arrays can be removed replaced after implantation. Methods Suprachoroidal were unilaterally implanted into 13 adult felines. After 1 month, surgically explanted (n = 6), (n = 5) undisturbed (n = 2). The retina was assessed periodically using fundus photography and optical coherence tomography. Three months initial implantation, function of by measuring responses visual cortex to electrical stimulation. histopathology tissues surrounding implant examined. Results Array explantation replacement successful in all cases. Fundus showed localized disruption tapetum lucidum near implant's tip seven subjects following implantation. Although tomography changes, there no widespread statistically significant differences thickness layers choroid. distance between electrodes increased device but returned control values within eight weeks (P < 0.03). Staphylomas developed scleral wound five animals explantation. Device did not alter cortical evoked potential threshold. Histopathology outer nuclear layer thinning, tapetal pseudo-rosette formation, overall morphology preserved. Conclusions It feasible remove replace conformable medical grade silicone suprachoroidally. requires careful closure minimize risk staphylomas.