One-Year Anatomical and Functional Outcomes of the Argus II Implantation in Korean Patients with Late-Stage Retinitis Pigmentosa: A Prospective Case Series Study

Abstract

Purpose: To report the anatomical and functional outcomes of Argus II retinal prosthesis implantation in Korean patients. Methods: We included 5 consecutive patients with end-stage retinitis pigmentosa (RP) who underwent Argus II retinal prosthesis implantation and were followed for at least 12 months. The transcorneal electrical evoked response was utilized for patient selection. We used intraoperative optical coherence tomography (OCT) for optimal placement of the array and provided specialized vision rehabilitation training. A morphological evaluation using SD-OCT and a functional evaluation using computer-based visual function tests, a letter-reading ability test, and the Functional Low-Vision Observer Rated Assessment (FLORA) were conducted. Results: Postoperatively, the array was completely apposed to the retinal surface in all eyes, except for one eye which had a preexisting macular concavity. Fibrosis-like tissues of ≥50-μm thickness developed at the interface in 2 eyes. All of the patients showed improvement in computer-based visual function tests and could read ETDRS letters at a distance of 50 cm. Three patients could read Korean words. FLORA was improved in all patients, mainly in tasks of visual mobility, daily activities, and social interactions. Conclusions: Along with good anatomical outcomes and specialized rehabilitation practices, recipients of the Argus II implant showed profound improvements in functional vision and mobility.