Adapted Surgical Procedure for Argus II Retinal Implantation: Feasibility, Safety, Efficiency, and Postoperative...

To evaluate the feasibility, safety, and efficiency of an adapted surgical procedure used for postmarket Argus II implantations, so as to lower risks of postoperative hypotony or conjunctivoscleral erosion, and to describe the observed anatomic characteristics of the positioning of the implanted array.

Single-arm prospective multicenter clinical trial.

Eighteen consecutive patients with end-stage retinitis pigmentosa.

To protect the site of insertion of the cable of the device, a scleral flap was systematically added to the standardized implantation procedure. It was associated with temporalis fascia autograft, so as to cover the episcleral-fixed electronics case. Intraoperative and postoperative data at day 1, weeks 1 and 2, and months 1, 3, and 6 were collected. Postoperative distance between electrode-array and retina was measured on spectral-domain optical coherence tomography images. Position of the array was evaluated on fundus images between months 1 and 6.

Feasibility of the modified surgical technique (time constraints, intraoperative complications), variations of intraocular pressure over time, postoperative ocular findings and adverse events, postoperative distance between the array and the retina, and rotation of the array between months 1 and 6 after implantation.

The adapted surgical technique was performed easily without associated specific complications. No cases of chronic hypotony or conjunctivoscleral erosion were reported. One serious device/procedure-related adverse event was recorded (sterile posterior uveitis), which resolved after vitrectomy. Postoperative distance between array and retina was variable: full apposition was achieved in 4 patients (22.22%), partial apposition observed in 9 patients (50.00%), and absence of strict apposition noted in 5 patients (27.78%, 4 of whom had posterior staphyloma). A statistically significant slight rotation of the array was observed between months 1 and 6 (P < 0.0001), occurring downwardly in 68.75% of cases.

The combined use of scleral flap and temporalis fascia autograft was easily achieved and effective in preventing hypotony and conjunctival erosion in our study. Postoperative distance between semirigid array and retinal surface was variable, and increased in the case of preoperative staphyloma. A slight rotation of the device occurred over time. Further studies based on larger samples are needed to confirm our findings and determine their functional consequences.