The EPIRET3 system can be successfully implanted and explanted in patients with blindness and RP. The surgical steps are feasible, and the postoperative follow-up disclosed an acceptable range of adverse events.

PurposeTo evaluate the technique, safety, and efficacy of the retropupillary implantation of iris-claw intraocular lenses in a long-term follow-up study.Patients and methodsThis retrospective study included 31 eyes of 31 patients who underwent an Artisan aphakic intraocular lens implantation between January 2006 and February 2011 at the University Hospital Essen, Essen, Germany and at the Zentrum für Augenheilkunde PD Dr Laube, Düsseldorf, Germany. Preoperative data collected included demographics, etiology of aphakia, previous surgeries, preoperative eye pathology, intraocular pressure, clinical signs of endothelial cell loss, and best corrected visual acuity. Operative data and postoperative outcomes included the best corrected visual acuity, lens position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, development of macular edema, and other complications.ResultsThirty-one patients were included. The mean follow-up was 25.2 months (range: 4–48 months). The mean best corrected visual acuity postoperatively was 0.64 logarithm of the minimum angle of resolution (logMAR) and varied from 0 logMAR to 3 logMAR. Some patients had a low visual acuity preoperatively because of preoperative eye pathologies. In 22 patients the visual acuity improved, in two patients the visual acuity remained unchanged, and seven patients showed a decreased visual acuity. Complications were peaked pupils (n=10) and retinal detachment in one case. Four patients showed an iris atrophy and high intraocular pressure was observed only in one patient. Subluxation of the intraocular lens, endothelial cell loss, and macular edema were not observed.ConclusionThe presented long-term results demonstrate that retropupillary iris-claw lens implantation is a safe and effective method for the correction of aphakia in patients without capsule support. This surgical procedure has the advantages of a posterior chamber implantation with a low intraoperative and postoperative risk profile.

. Purpose:  To determine the threshold charges needed for eliciting visual perceptions through acute electrical stimulation of the human retina in patients suffering from retinitis pigmentosa, using an epiretinal microelectrode array. Methods:  In a multicentre study, 20 patients (average age 55 years) with visual acuities ranging from 4/200 to no light perception were included. The stimulation procedure was performed during a pars plana vitrectomy, for a maximum of 45 min, by using a microcontact film with IrOx electrodes connected by cable to a current generator. After repeated stimulation and threshold charge determination, the microelectrode array was removed. Results:  Nineteen of 20 patients stated in the postoperative interviews that they experienced one or more visual perceptions with close time correlation to single stimulation events. Minimum threshold charges needed to generate visual perceptions could be measured and verified in 15 patients. The charge level ranged from 20 to 768 nC with single or multiple electrodes. One patient suffered a retinal detachment during the procedure; this patient’s retina was successfully reattached. There were no further adverse reactions observed during the 3‐month follow‐up. Conclusion:  Acute epiretinal stimulation of the human retina, using a microelectrode array, can elicit visual perceptions in blind patients with retinitis pigmentosa.

The absorption characteristics of some UV and blue-light-filtering IOLs resembled those of the crystalline lens, but some differed. Long-term clinical trials should be performed to determine how blue-blocking IOLs affect the risk for progression of age-related macular degeneration.

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Objective. The restoration of vision in blind patients suffering from degenerative retinal diseases like retinitis pigmentosa may be obtained by local electrical stimulation with retinal implants. In this study, a very large electrode array for retinal stimulation (VLARS) was introduced and tested regarding its safety in implantation and biocompatibility. Further, the array’s stimulation capabilities were tested in an acute setting. Approach. The polyimide-based implants have a diameter of 12 mm, cover approximately 110 mm2 of the retinal surface and carrying 250 iridium oxide coated gold electrodes. The implantation surgery was established in cadaveric porcine eyes. To analyze biocompatibility, ten rabbits were implanted with the VLARS device, and observed for 12 weeks using slit lamp examination, fundus photography, optical coherence tomography (OCT) as well as ultrasound imaging. After enucleation, histological examinations were performed. In acute stimulation experiments, electrodes recorded cortical field potentials upon retinal stimulation in the visual cortex in rabbits. Main results. Implantation studies in rabbits showed that the implantation surgery is safe but difficult. Retinal detachment induced by retinal tears was observed in five animals in varying severity. In five cases, corneal edema reduced the quality of the follow-up examinations. Findings in OCT-imaging and funduscopy suggested that peripheral fixation was insufficient in various animals. Results of the acute stimulation demonstrated the array’s ability to elicit cortical responses. Significance. Overall, it was possible to implant very large epiretinal arrays. On retinal stimulation with the VLARS responses in the visual cortex were recorded. The VLARS device offers the opportunity to restore a much larger field of visual perception when compared to current available retinal implants.

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This paper reports on methods and technical equipment to investigate the epiretinal stimulation of the retina in blind human subjects in acute trials. Current is applied to the retina through a thin, flexible microcontact film (microelectrode array) with electrode diameters ranging from 50 to 360 microm. The film is mounted in a custom-designed surgical tool that is hand-held by the surgeon during stimulation. The eventual goal of the work is the development of a chronically implantable retinal prosthesis to restore a useful level of vision to patients who are blind with outer retinal degenerations, specifically retinitis pigmentosa and macular degeneration.