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Background: Macular hole (MH) is a rare complication of retinitis pigmentosa (RP) and has an adverse impact on residual visual function. At present, the underlying mechanisms are not fully understood and surgical experience is limited., Methods: We reviewed the medical records and optical coherence tomography (OCT) scans in a cohort of eight eyes of seven RP patients with MH in order to report their OCT features and vitreoretinal surgical prognosis., Results: This study includes four lamellar macular holes (LMHs) and four full-thickness macular holes (FTMHs). Pre-operative OCT revealed other macular abnormalities in all eyes, such as epiretinal membrane (ERM), cystoid macular edema (CME), lamellar hole-associated epiretinal proliferation (LHEP) and vitreoretinal traction. MH progression and subjective vision worsening were noted in one LMH eye during a seven-month follow-up. All holes closed after vitrectomy with internal limiting membrane (ILM) peeling. At final follow-up, one eye had improved vision and seven eyes remained stable compared to baseline., Conclusions: The occurrence of MH in RP is accompanied by various imaging characteristics, such as ERM, CME and LHEP, suggesting a multifactorial pathogenesis. Considering poor vision in most RP patients with potentially progressive MH, surgery appears to be effective in maintaining or improving the central vision in a period of time. Thus, vitrectomy should be performed as soon as possible and flap-assisted techniques or episcleral surgeries are needed for some special cases., (© 2024. The Author(s).)

Introduction: Meckel-Gruber Syndrome (MKS) is an autosomal recessive genetic disorder, notable for its triad of occipital encephalocele, polycystic renal dysplasia, and postaxial polydactyly. Identified by Johann Friederich Meckel in 1822, MKS is categorized as a ciliopathy due to gene mutations. Diagnosis is confirmed by the presence of at least two key features. The condition is incompatible with life, leading to death in the womb or shortly after birth. Recent studies have largely focused on the genetic aspects of MKS, with limited information regarding the impact of neurosurgical approaches, particularly in treating encephaloceles., Methods: A systematic review was performed according to the PRISMA statement. The PubMed, Embase, and Web of Science databases were consulted for data screening and extraction, which was conducted by two independent reviewers. The search strategy aimed to encompass studies documenting cases of MKS with published reports of encephalocele excisions, and the search strings for all databases were: Meckel-Gruber syndrome OR Meckel Gruber syndrome OR Meckel-gruber OR Meckel Gruber., Results: The study included 10 newborns with MKS associated with occipital encephalocele or meningocele, all of whom underwent surgical repair of the occipital sac. The mean gestational age at birth was 36 (± 2) weeks. The mean of birth weight was 3.14 (± 0.85) kilograms. The average head circumference at birth was 33.82 cm (± 2.17). The mean diameter of the encephalocele/meningocele was 5.91 (± 1.02) cm. Other common central nervous system abnormalities included hydrocephalus, Dandy-Walker malformation, and agenesis of the corpus callosum. 40% required shunting for hydrocephalus. Surgery to remove the occipital sac occurred at a median age of 2.5 days (1.5-6.5). The most common post-surgical complication was the need for mechanical ventilation. The most common cause of death was pneumonia and the median age at death was 6.66 (0.03-18) months., Conclusion: Our findings suggest that neurosurgical intervention, especially for managing encephaloceles, may offer some improvement in survival, albeit within a context of generally poor prognosis. However, these results should be interpreted with caution., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To report visual acuity (VA) outcomes, intraoperative and postoperative complications of isolated cataract surgery in eyes with retinitis pigmentosa (RP), compared with non-RP-affected eyes., Design: Retrospective clinical cohort study., Methods: A total of 113,389 eyes underwent cataract surgery between July 2003 and March 2015 at 8 clinical sites in the United Kingdom. Eyes with RP as the only comorbid pathology and eyes without any ocular comorbidities (controls) undergoing cataract surgery were compared. VA at 4 to 12 weeks postoperatively and rates of intraoperative and postoperative complications are reported., Results: Seventy-two eyes had RP. The mean age in the RP group was 57 ± 15 compared to 75 ± 10 in controls (P < .001). Females represented 46% of RP cases and 60% of controls (P = .06). Preoperative VA (mean LogMAR = 1.03 vs 0.59, P < .001) and postoperative VA (0.71 vs 0.14, P < .001) were worse in RP group. The mean VA gain was 0.25 ± 0.60 LogMAR in RP vs 0.43 ± 0.48 LogMAR in controls (P < .001). There were no significant differences in the rate of intraoperative pupil expansion use, posterior capsular tears, or zonular dialysis. Postoperative cystoid macular edema developed in 6.9% of RP eyes and 1% of controls (P < .001). The need for IOL repositioning or exchange was not statistically different between the two groups., Conclusion: Cataract surgery can improve vision in eyes with RP and cataract. Intraoperative complications were similar to control eyes; however, RP eyes experienced more frequent postoperative cystoid macular edema., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Outcomes of retinal detachment (RD) have been discussed in detail in many reports of patients with retinitis pigmentosa (RP). This study tries to understand the outcomes of vitreoretinal (VR) surgery for indications other than RD in the eyes with RP., Methods: This is a retrospective study that includes clinical data from January 2013 to December 2021. Patients with RP who were treated with a VR surgical intervention were included in the study. The primary outcome of the study was to assess the changes in best-corrected visual acuity., Results: Forty-four eyes of 40 patients with RP were included in the study. Nearly half of the eyes (43%, 19/44) presented from 1 month to 1 year after the onset of diminished vision, with or without floaters. The mean ± standard deviation (SD) best-corrected visual acuity (BCVA) at presentation was 1.30 ± 0.79 logMAR (20/400 ± 20/125). The major surgical indications were vitreous opacities (43.2%, 19/44) and subluxated/dislocated cataractous lenses (25%, 11/44). The median follow-up duration was 8 months (interquartile range (IQR): 1.5-27). Approximately 77% (34/44) of the eyes had improvement in vision. The mean postoperative BCVA at the last follow-up was 0.95 ± 0.73 logMAR (p-value: 0.03)., Conclusions: Most eyes with RP recovered well after VR surgical interventions, with short-term improvements in visual acuity. It may be crucial to address the vitreous opacities and membranes as they hinder the residual central island of vision in RP. However, appropriate counselling is required regarding the progressive nature of retinal neuronal degeneration., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Allogenic transplantation of retinal pigmented epithelium monolayer sheet has experienced bottlenecks due to imperfect surgical techniques. In this study, we developed a novel approach for allogenic transplantation of big sheets of retinal pigment epithelium (RPE)-Bruch membrane complex., Methods: RPE-Bruch membrane complex sheets of 5 × 6 mm2 to 10 × 10 mm2 were taken from donated eyes. Through a novel approach, the sheets of RPE-Bruch membrane complex were transplanted into the subretinal space of eight eyes (8 patients) with late-stage retinitis pigmentosa. The patients were followed up for 5 ± 2 months., Results: All RPE-Bruch membrane complexes were successfully inserted into the subretinal space during the surgery. Follow-up examinations also showed that the grafts attached well to the transplantation site. No rejection or retinal detachment was found., Conclusion: Through our technique, big sheets of allogenic RPE-Bruch membrane complexes could be implanted into the subretinal space smoothly. This novel approach may be useful for big sheet of allogenic RPE-derived or stem cells-derived RPE transplantation in the treatment of RP and other retinal dystrophic diseases.

Retinitis pigmentosa (RP) is an inherited bilateral retinal degenerative disease with an incidence of 1 in 4000 people. RP affects more than 1 million individuals worldwide. Although night blindness and restricted visual field are the most typical symptoms of these individuals, generalized vision loss due to cataracts can be expected in the latter stages of the disease. It has been demonstrated that posterior subcapsular cataract is the most prevalent cataract in younger individuals with RP, as opposed to age-related cataracts. Although most ophthalmologists may have a negative view of cataract surgery in patients with RP, it appears that it can play an important role in the visual restoration of patients with RP. However, there are concerns about performing cataract surgery for patients with RP. Herein, a systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses on databases of MEDLINE and Scopus., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS.)

Background: The Argus II Retinal Prosthesis System (Second Sight Medical Products, Sylmar, California) is an epiretinal prosthesis that serves to provide useful vision to people who are affected by retinal degenerative diseases such as retinitis pigmentosa (RP). The purpose of this study was to analyze postoperative movement of the electrode array., Methods: Five patients diagnosed with profound retinal dystrophy who have undergone implantation of retinal prosthesis at Stony Brook University Hospital. Fundoscopy was performed at postoperative month 1 (M1), month 3 (M3), month 6 (M6), month 12 (M12), and month 24 (M24) visits. Fundoscopy was extracted and analyzed via NIH ImageJ. Data analysis was completed using IBM SPSS. Various lengths and angles were measured each postoperative month using ImageJ., Results: There was no significant change in distance between the optic disc and the surgical handle (length AB) over the two-year span (F = 0.196, p = 0.705). There was a significant change in distance of length AB over time between patients between M3 and M6 (p = 0.025). A repeated measures ANOVA revealed that there was statistically significant change of the optic disc-tack-surgical handle angle (𝛾) (M1 to M24) (F = 3.527, p = 0.030). There was no significant change in angle 𝜟 (the angle to the horizontal of the image), angle 𝜶 (tack-optic disc-surgical handle), and angle 𝜷 (optic-disc-surgical handle-tack)., Conclusion: Our results demonstrate that there may be postoperative movement of the retinal prosthesis over time, as a statistically significant downward rotation is reported over the 2 years span. It is important, moving forward, to further study this movement and to take into consideration such movement when designing retinal implants. It is important to note that this study is limited by the small sample size, and therefore, the conclusions drawn are limited., (© 2023. The Author(s).)

Purpose: To assess the visual outcome of cataract surgery in patients with retinitis pigmentosa (RP)., Design: Retrospective, noncomparative clinical study., Methods: Preoperative, intraoperative, and postoperative data of patients with RP who were undergoing cataract surgery were collected from several expertise centers across Europe., Results: In total, 295 eyes of 226 patients were included in the study. The mean age at surgery of the first eye was 56.1 ± 17.9 years. Following surgery, best-corrected visual acuity (BCVA) improved significantly from 1.03 to 0.81 logMAR (ie, 20/214 to 20/129 Snellen) in the first treated eye (-0.22 logMAR; 95% CI = -0.31 to -0.13; P < .001) and from 0.80 to 0.56 logMAR (ie, 20/126 to 20/73 Snellen) in the second treated eye (-0.24 logMAR; 95% CI = -0.32 to -0.15; P < .001). Marked BCVA improvements (postoperative change in BCVA of ≥0.3 logMAR) were observed in 87 of 226 patients (39%). Greater odds for marked visual improvements were observed in patients with moderate visual impairment or worse. The most common complications were zonular dialysis (n = 15; 5%) and (exacerbation of) cystoid macular edema (n = 14; 5%), respectively. Postoperative posterior capsular opacifications were present in 111 of 295 eyes (38%)., Conclusion: Significant improvements in BCVA are observed in most patients with RP following cataract surgery. Baseline BCVA is a predictor of visual outcome. Preoperative evaluation should include the assessment of potential zonular insufficiency and the presence of CME, as they are relatively common and may increase the risk of complications., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To discuss the role of advanced retinal implants in retinitis pigmentosa and age-related macular degeneration., Design: Presented by Mark S. Humayun as the Charles Schepen's Lecture on the Retina Subspecialty Day of the American Academy of Ophthalmology in 2021., Participants: The details of subjects, participants, and controls are provided in the references pertaining to each study., Methods: Review of published literature and clinical trials., Main Outcome Measures: Visual and anatomic outcomes from retinal implants., Results: Retinal implants have been researched over the past few decades, and some have been advanced into the clinic. Two types of implants-bioelectronic and stem cell-based-have shown promising results in restoring some level of vision in patients with inherited retinal degeneration and geographic atrophy. These implants differ in their constructions, locations of implantation, and safety profiles. The results from some of these retinal implants have shown signs of efficacy, and 1 retinal implant, the Argus II, has been approved by the United States Food and Drug Administration., Conclusions: Careful consideration of the design of the implant and associated surgical techniques are necessary to obtain a stable and effective long-term interface between the implant and the retina., (Copyright © 2022 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Introduction: Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of hereditary disorders in which there is progressive loss of photoreceptors and pigment epithelial function culminating in complete vision loss. Unfortunately, given the disease's devastating effects, it is untreatable and there is often little that can be done to improve visual outcomes in these patients. The lack of curative intervention creates a challenge in the management of RP and its progression. As such, the main goal is to slow down the apoptosis and loss of photoreceptors in order to delay visual deterioration., Materials and Methods: We present two case illustrations of RP treated with WJ-MSC implanted in the deep subtenon space. Each patient underwent 4 sessions ranging from 1 to 3 months apart., Results: At 3, 6, 9 and 12 months follow-up, the following were observed:(i) Both patients had no change in visual acuity and no further deterioration in vision or visual field.(ii) Optical coherence tomography showed a layer of hyperreflective material noted at the IO/OS junction area suggestive of a layer of new photoreceptors. The changes were noted in the macula and extramacular region for both patients.(iii) Both patients reported better discernment of colors and better vision at certain times during the day. (iv) No systemic or ocular adverse events were observed in the 12 month follow-up following the subtenon implantation of WJ-MSC., Conclusion: Subtenon implantation of WJ-MSC appears to be a feasible and safe option to consider in delaying the progression of retinal degeneration and improving the quality of life affected by visual deterioration in patients with RP.

Purpose: To report the long-term observations of the electrode-tissue interface and perceptual stability in humans after chronic stimulation with a 44-channel suprachoroidal retinal implant., Methods: Four subjects (S1-4) with end-stage retinitis pigmentosa received the implant unilaterally (NCT03406416). Electrode impedances, electrode-retina distance (measured using optical coherence tomography imaging), and perceptual thresholds were monitored up to 181 weeks after implantation as the subjects used the prosthesis in the laboratory and in daily life. Stimulation charge density was limited to 32 µC/cm2 per phase., Results: Electrode impedances were stable longitudinally. The electrode-retina distances increased after surgery and then stabilized, and were well-described by an asymptotic exponential model. The stabilization of electrode-retina distances was variable between subjects, stabilizing after 45 weeks for S1, 63 weeks for S2, and 24 weeks for S3 (linear regression; Pgradient > 0.05). For S4, a statistically significant increase in electrode-retina distance persisted (P < 0.05), but by the study end point the rate of increase was clinically insignificant (exponential model: 0.33 µm/wk). Perceptual electrical thresholds were stable in one subject, decreased over time in two subjects (linear model; P < 0.05), and increased slightly in one subject but remained within the predefined charge limits (P = 0.02)., Conclusions: Chronic stimulation with the suprachoroidal retinal prosthesis over 3 years resulted in stable impedances, small individual changes in perceptual electrical thresholds, and no clinically significant increase in electrode-retina distances after a period of settling after surgery., Translational Relevance: Chronic stimulation with the 44-channel suprachoroidal retinal implant with a charge density of up to 32 µC/cm2 per phase is suitable for long-term use in humans.

Purpose: To describe a surgical approach using intraoperative optical coherence tomography and endoscopy for successful Argus II retinal prosthesis system removal., Methods: Retrospective review of a patient undergoing Argus II explantation 8 months after initial implantation., Results: Successful explantation of the Argus II device was performed in this patient., Conclusion: Explantation of the Argus II device can be a difficult surgery, and intraoperative optical coherence tomography and endoscopy can be used to help avoid potential complications.

Purpose: To investigate the long-term outcomes of cataract surgery in patients with retinitis pigmentosa (RP)., Design: Retrospective, observational study., Participants: Sixty-four patients with typical RP (22 men, 42 women; average age, 62.8 ± 10.1 years) who underwent cataract surgery at Kyushu University Hospital between May 2007 and October 2015 and were followed up for ≥3 years after the surgery., Methods: Differences between presurgery and postsurgery visual function, including best-corrected visual acuity (BCVA) and parameters in the Humphrey field analyzer (HFA) examination using the central 10-2 program, were investigated. The presurgery conditions of the foveal ellipsoid zone (EZ) were classified into 3 grades (grade 1: invisible; grade 2: abnormal; grade 3: normal) based on OCT findings., Main Outcome Measures: BCVA, the retinal sensitivity in the HFA 10-2 test., Results: Cataract surgery was performed in 96 eyes, with an average follow-up period of 5.8 ± 2.4 years. The mean presurgery BCVA was 0.64 ± 0.52 logarithm of the minimum angle of resolution (logMAR), and the final postsurgery BCVA was 0.61 ± 0.67 logMAR (P = 0.57). Significant improvement in the postsurgery BCVA was observed only in eyes with preserved foveal EZ (grade 3) (P < 0.01). In 62 eyes of 45 patients who underwent the HFA 10-2 test, the mean values of deviation, macular sensitivity, and foveal sensitivity at the final visit were significantly decreased compared with preoperative values (P < 0.01), whereas those in grade 3 eyes did not change significantly after the surgery (P = 0.13)., Conclusions: In the long-term course after cataract surgery in patients with RP, many patients experienced vision loss with progression of the disease. The preoperative finding of preserved foveal EZ was associated with a better visual prognosis, suggesting that EZ evaluation is useful for predicting the long-term visual outcome of cataract surgery in patients with RP., (Copyright © 2021 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

In February 2013, the Argus® II Retinal Prosthesis System (Second Sight Medical Products, Inc., Sylmar, CA, US) became the first "bionic eye" approved by the FDA to restore useful vision in patients previously blinded by end-stage retinitis pigmentosa, a hereditary, progressive degeneration of the outer retinal photoreceptor cells. The system captures and converts an external optical input into an electrical signal that activates an epiretinal electrode array on the inner surface of the retina. This signal bypasses dysfunctional photoreceptors and directly stimulates the functional inner retina, thus transmitting information to the visual cortex and creating artificial vision. This article describes the first implantation of the Argus II Retinal Prosthesis System in the Asia-Pacific region, which occurred in a deaf and blind 72-year-old Japanese American woman with Usher syndrome. At 57 months after her operation, the patient uses the device daily to perform visual tasks, and the microelectrode array remains in the proper position on the macula. This case demonstrates the long-term safety and efficacy of the Argus II epiretinal implant, which allowed a functionally blind patient to gain meaningful vision., (©Copyright 2021 by University Health Partners of Hawai‘i (UHP Hawai‘i).)

Purpose: To evaluate the post-approval long-term outcomes of the Argus II Retinal Prosthesis, with a specific focus on its functional visual benefit in patients' daily activities., Methods: Eighteen patients with bare light perception due to end-stage retinitis pigmentosa were included in a French prospective, multicentre, single-arm study and followed for 2 years. Visual benefit in patients' daily activities was monitored through the use of the Functional Low-vision Observer Rated Assessment (FLORA), and the final score at 2 years was the primary effectiveness outcome. Standardized visual assessments were also performed. Device- or procedure-related adverse events were recorded., Results: Seventeen subjects completed the study. Positive impacts of the Argus II system on functional vision and well-being were demonstrated for over 70% of subjects on the FLORA. Among the daily activities/tasks tested, finding doorways was one of the most statistically significantly improved tasks (p < 0.001), along with estimating the size of an obstacle (p < 0.001), visually locating a place setting on a dining table (p < 0.001) and visually locating people in a non-crowded setting (p < 0.001). Visual function was improved on most standardized tests. Only two device- or procedure-related serious adverse events were observed (one vitreous haemorrhage and one endophthalmitis, both resolved with treatment). No explantation was required., Conclusion: This first report of a completed post-approval study of Argus II with a two-year follow-up demonstrates the safety and effectiveness of the Argus II System in a real-world cohort of patients and further highlights its real functional benefit in implanted patients' daily activities., (© 2020 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: Retinal degenerative diseases, e.g., retinitis pigmentosa, cause a severe decline of the visual function up to blindness. Treatment still remains difficult; however, implantation of retinal prostheses can help restoring vision. In this study, the biocompatibility and surgical feasibility of a newly developed epiretinal stimulator (OPTO-EPIRET) was investigated. The previously developed implant was extended by an integrated circuit-based optical capturing, which will enable the immediate conversion of the visual field into stimulation patterns to stimulate retinal ganglion cells., Results: The biocompatibility of the OPTO-EPIRET was investigated in vitro using the two different cell lines L-929 and R28. Direct and indirect contact were analyzed in terms of cell proliferation, cell viability, and gene expression. The surgical feasibility was initially tested by implanting the OPTO-EPIRET in cadaveric rabbit eyes. Afterwards, inactive devices were implanted in six rabbits for feasibility and biocompatibility testings in vivo. In follow-up controls (1-12 weeks post-surgery), the eyes were examined using fundoscopy and optical coherence tomography. After finalization, histological examination was performed to analyze the retinal structure. Regarding the in vitro biocompatibility, no significant influence on cell viability was detected (L929: < 1.3% dead cells; R-28: < 0.8% dead cells). The surgery, which comprised phacoemulsification, vitrectomy, and implantation of the OPTO-EPIRET through a 9-10 mm corneal incision, was successfully established. The implant was fixated with a retinal tack. Vitreal hemorrhage or retinal tearing occurred as main adverse effects. Transitional corneal edema caused difficulties in post-surgical imaging., Conclusions: The OPTO-EPIRET stimulator showed a good biocompatibility profile in vitro. Furthermore, the implantation surgery was shown to be feasible. However, further design optimization steps are necessary to avoid intra- and postoperative complications. Overall, the OPTO-EPIRET will allow for a wide visual field and good visual acuity due to a high density of electrodes in the central retina., (© 2021. The Author(s).)

Purpose: In a clinical trial (NCT03406416) of a second-generation (44-channel) suprachoroidal retinal prosthesis implanted in subjects with late-stage retinitis pigmentosa (RP), we assessed performance in real-world functional visual tasks and emotional well-being., Methods: The Functional Low-Vision Observer Rated Assessment (FLORA) and Impact of Vision Impairment-Very Low Vision (IVI-VLV) instruments were administered to four subjects before implantation and after device fitting. The FLORA contains 13 self-reported and 35 observer-reported items ranked for ease of conducting task (impossible-easy, central tendency given as mode). The IVI-VLV instrument quantified the impact of low vision on daily activities and emotional well-being., Results: Three subjects completed the FLORA for two years after device fitting; the fourth subject ceased participation in the FLORA after fitting for reasons unrelated to the device. For all subjects at each post-fitting visit, the mode ease of task with device ON was better or equal to device OFF. Ease of task improved over the first six months with device ON, then remained stable. Subjects reported improvements in mobility, functional vision, and quality of life with device ON. The IVI-VLV suggested self-assessed vision-related quality of life was not impacted by device implantation or usage., Conclusions: Subjects demonstrated sustained improved ease of task scores with device ON compared to OFF, indicating the device has a positive impact in the real-world setting., Translational Relevance: Our suprachoroidal retinal prosthesis shows potential utility in everyday life, by enabling an increased environmental awareness and improving access to sensory information for people with end-stage RP.

Retinitis pigmentosa can be associated with exudative vasculopathy in rare instances, which can manifest as retinal vasoproliferative tumours. We present the case of a 33-year-old woman previously diagnosed with retinitis pigmentosa sine pigmentosa in both eyes. She was asymptomatic and just came in for a routine follow-up eye examination. Thorough examination of the peripheral retina on the right eye revealed a dome-shaped retinal tumour with a feeder vessel and surrounding exudative changes at the superotemporal periphery, consistent with a secondary retinal vasoproliferative tumour from retinitis pigmentosa. She subsequently underwent focal laser photocoagulation of the tumour which resulted in tumour stabilisation. While exudative vasculopathy is very uncommon in retinitis pigmentosa, ophthalmologists need to be aware of its occurrence in such patients. Vision loss may occur from exudation, haemorrhage, retinal detachment and neovascularisation. A thorough examination of the peripheral retina is warranted in these cases., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To describe two methods of measuring Argus II array-retina distance and to correlate array-retina distance to electrode stimulation thresholds., Methods: This was a case series of eight patients implanted with the Argus II. Spectral domain-optical coherence tomography array-retina distance was measured by two methods and correlated to corresponding electrode thresholds: (1) array-retina distance at each array corner and the largest array-retina distance and (2) using manual optical coherence tomography segmentation, the average array-retina distance was determined for each group of four electrodes. Patients 1-5 and 6-8 were analyzed separately due to a different threshold programming software., Results: The Spearman's rank coefficient between array-retina distance and thresholds was -0.006 ( p  = 0.98) for patients 1-5, and 0.16 ( p  = 0.59) for patients 6-8 with the first method. The Spearman's rank coefficient was 0.25 ( p  < 0.001) for patients 1-5 and 0.36 ( p  < 0.001) for patients 6-8 with the second method., Conclusion: There is a positive correlation between array-retina distance and threshold measurements when measuring the entire array but not when using a faster measurement method of four corners and largest array-retina distance.

Purpose: To evaluate the motility of the eye in patients with the RETINA IMPLANT Alpha AMS., Methods: Eye motility was determined in eight gaze directions in ten blind retinitis pigmentosa patients, who had received the RETINA IMPLANT Alpha AMS, before implantation of the subretinal implant and at six time-points up to one year after., Results: The analysis of eye motility showed a restriction in the upgaze and gaze to the temporal side directly after surgery in eight of the nine patients included. The degree of motility restriction decreased continuously with recovery during the observation time. One year after surgery, eye motility was still restricted in the majority of patients, especially in the upgaze to the temporal side at 20° (five of seven patients)., Conclusion: Retinal implants with intraorbital parts (e.g. connecting cables) caused restriction in the temporal and superior viewing directions in the majority of patients. Although this restriction might be cosmetically visible, this limitation in eye motility has no effects on the monocular vision and the implant's efficacy for daily use., (© 2020 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Purpose: 1) To investigate morphologic and histochemical characteristics of an epiretinal fibrosis removed in an Argus II-implanted eye; 2) to evaluate the Argus II function before and after the fibrosis removal, and 3) to compare morphologic and functional data., Methods: Fibrosis, which developed between the Argus II prosthesis and the retina two years after implant, was surgically removed. Its morphologic and histochemical characteristics were evaluated both in light and transmission electron microscopy, with special stains and immunohistochemistry. The Argus II function was evaluated during the follow-up before surgical removal and 1 month later., Results: Fibrosis was successfully removed. It was composed of a fibrotic tissue with spindle cells arranged in nodular aggregates with a symmetric distribution, mixed with an inflammatory infiltrate. Extra- and intracellular, irregular, small iron particles were found and confirmed ultrastructural characterization with degenerative cellular changes. The repositioned Argus II restored, and its function was partially nearly to normal values 1 month after surgery., Conclusion: Fibrosis can develop between the Argus II and the retina with increasing reduced function. Morphologic characteristics of the removed fibrosis suggested a pathogenesis based on an inflammatory process involved in a foreign body reaction with progressing connective tissue deposition leading to sclerosis. Adequate clinical follow-up is critical to successful removal of the fibrosis with reactivation of the Argus II function.

Retinitis pigmentosa (RP) is a common inherited retinal disease for which effective treatment is not yet known. This review sought to analyze the available medical literature covering the efficacy of different forms of laser treatment for RP in laboratory and clinical trials. The PubMed database was searched using the following phrases: "laser photocoagulation", "subthreshold laser", "nanolaser", "micropulse laser", "retinitis pigmentosa", "rod-cone dystrophy", and "retinal dystrophy". Results were stratified as clinical or experimental studies. Six studies involving animal models and three studies involving human subjects that examined laser treatment in RP were found. Laboratory studies on rodents favored classic laser photocoagulation as the most effective therapy for slowing the progression of proto-oncogene tyrosine-protein kinase MER-related RP. Two clinical studies on humans suggested transient but robust functional benefits of subthreshold micropulse laser treatment in RP. The available material is too scarce to define laser treatment as a standard procedure to treat RP in humans. Nondamaging retinal laser therapy should be tested more intensively in clinical trials as there is no proven negative side effect of that treatment and the theoretical background, especially the chaperone and reparative roles of heat shock proteins elicited during the procedure, supports this form of RP management.

Background: Post-implantation visual outcomes in patients with the Argus II Retinal Prosthesis is dependent on a multitude of factors including the positioning of the electrode array on the retina. The purpose of this study is to determine whether the average electrode array-retina gap distance correlates with objective visual function outcomes and sensitivity detection thresholds in patients implanted with the Argus II Retinal Prosthesis., Methods: Five patients with implantation of the Argus II Retinal Prosthesis were enrolled in this single-institution retrospective study. Patient demographics were collected from medical records. Visual function data (Square Localization [SL] and Direction of Motion [DOM]) and Optical Coherence Tomography (Cirrus HD-OCT) images were extracted retrospectively from the Argus II Retinal Prosthesis Post-Approval study. Visual function tests were performed with the device OFF and ON at each study visit. Electrode array-retina gap distances were measured at each of the array's 60 electrodes using the Cirrus HD-OCT software in both the nasotemporal and superoinferior planes. Data was obtained at baseline, and post-operative month 1, month 3, month 6, and year 1. Sensitivity detection thresholds were obtained at the initial programming visit and each reprogramming session., Results: Three patients performed significantly better in SL visual function testing with the device ON. Patients that worsened in visual function testing with the device ON in both SL and DOM testing had a statistically significant decrease in performance. The electrode array-retina gap distance was found to effect performance in SL testing in a patient-dependent manner. No effect was found between the electrode-array gap distance and DOM testing or sensitivity detection threshold., Conclusion: Our results demonstrate that the electrode array-retina gap distance may affect visual function outcomes in SL testing in certain patients with the Argus II Retinal Prosthesis, and the direction and magnitude of this effect is likely patient-dependent. Furthermore, complete apposition between the electrode array and retina may not always be necessary to achieve optimal visual outcomes.

Retinal prostheses are designed to restore a basic sense of sight to people with profound vision loss. They require a relatively intact posterior visual pathway (optic nerve, lateral geniculate nucleus and visual cortex). Retinal implants are options for people with severe stages of retinal degenerative disease such as retinitis pigmentosa and age-related macular degeneration. There have now been three regulatory-approved retinal prostheses. Over five hundred patients have been implanted globally over the past 15 years. Devices generally provide an improved ability to localize high-contrast objects, navigate, and perform basic orientation tasks. Adverse events have included conjunctival erosion, retinal detachment, loss of light perception, and the need for revision surgery, but are rare. There are also specific device risks, including overstimulation (which could cause damage to the retina) or delamination of implanted components, but these are very unlikely. Current challenges include how to improve visual acuity, enlarge the field-of-view, and reduce a complex visual scene to its most salient components through image processing. This review encompasses the work of over 40 individual research groups who have built devices, developed stimulation strategies, or investigated the basic physiology underpinning retinal prostheses. Current technologies are summarized, along with future challenges that face the field., Competing Interests: Funding and Declaration of Competing Interest LA receives licensing royalties for purchase by commercial entities for the IVI-VLV tool and is supported by a NHMRC Next Generation Fellowship (1151055) and an NHMRC Project Grant (1082358). GD is a consultant to Second Sight Medical Products (USA), and receives licensing royalties for purchase by commercial entities for the ULV-VFQ tool. JW is a consultant to Second Sight Medical Products (USA). BJ is supported by NIH grants R01 EY015128, R01 EY028927, a P30 EY014800 Vision Core Grant and an unrestricted grant from Research to Prevent Blindness to the Moran Eye Center. RH is an employee of Pixium Vision (France). MM is a consultant to Pixium Vision (France) and receives support from the National Institute for Health Research (NIHR) London Biomedical Research Centre (BRC) at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology. MP and NB receive funding from Bionic Vision Technologies (Australia). DR is supported by the German Ministry for Education and Research, BMBF 031a308., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

A wireless photovoltaic retinal prosthesis is currently being studied with the aim of providing prosthetic vision to patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). The major challenge of a photovoltaic device is its limited power efficiency. Our retinal prosthetic design implements a unique divisional power supply scheme (DPSS) system that provides the electrical power generated by all of the solar cells to only a subset of electrodes at any moment in time. The aim of the present study was to systematically characterize the spatiotemporal integration performance of the system under various DPSS conditions using human subjects and a psychophysical approach. A 16x16 pixels LED array controlled by Arduino was used to simulate the output signal of the DPSS design, and human performance under different visual stimulations at various update frequencies was then used to assess the spatiotemporal capability of retinal prostheses. The results showed that the contrast polarity of the image, image brightness, and division number influenced the lower limit of the update frequency of the DPSS system, while, on the other hand, visual angle, ambient light level, and stimulation order did not affect performance significantly. Pattern recognition by visual persistence with spatiotemporal integration of multiple frames of sparse dots is a feasible approach in retinal prosthesis design. These findings provide an insight into how to optimize a photovoltaic retinal prosthesis using a DPSS design with an appropriate update frequency for reliable pattern recognition. This will help the development of a wireless device able to restore vision to RP and AMD patients in the future., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To analyze and provide an overview of the incidence, management, and prevention of conjunctival erosion in Argus II clinical trial subjects and postapproval patients., Methods: This retrospective analysis followed the results of 274 patients treated with the Argus II Retinal Prosthesis System between June 2007 and November 2017, including 30 subjects from the US and European clinical trials, and 244 patients in the postapproval phase. Results were gathered for incidence of a serious adverse event, incidence of conjunctival erosion, occurrence sites, rates of erosion, and erosion timing., Results: Overall, 60% of subjects in the clinical trial subjects versus 83% of patients in the postapproval phase did not experience device- or surgery-related serious adverse events. In the postapproval phase, conjunctival erosion had an incidence rate of 6.2% over 5 years and 11 months. In 55% of conjunctival erosion cases, erosion occurred in the inferotemporal quadrant, 25% in the superotemporal quadrant, and 20% in both. Sixty percent of the erosion events occurred in the first 15 months after implantation, and 85% within the first 2.5 years., Conclusion: Reducing occurrence of conjunctival erosion in patients with the Argus II Retinal Prosthesis requires identification and minimization of risk factors before and during implantation. Implementing inverted sutures at the implant tabs, use of graft material at these locations as well as Mersilene rather than nylon sutures, and accurate Tenon's and conjunctiva closure are recommended for consideration in all patients.

Purpose: To assess whether treatment with the Limoli Retinal Restoration Technique (LRRT) can be performed in patients with retinitis pigmentosa (RP), grafting the autologous cells in a deep scleral pocket above the choroid of each eye to exert their beneficial effect on the residual retinal cells., Methods: The patients were subjected to a complete ophthalmological examination, including best corrected visual acuity (BCVA), close-up visus measurements, spectral domain-optical coherence tomography (SD-OCT), microperimetry (MY), and electroretinography (ERG). Furthermore, the complete ophthalmological examination was carried out at baseline (T0) and at 6 months (T180) after surgery. The Shapiro-Wilk test was used to assess the normality of distribution of the investigated parameters. A mixed linear regression model was used to analyse the difference in all the studied parameters at T0 and T180, and to compare the mean change between the two groups. All statistical analyses were performed with STATA 14.0 (Collage Station, Texas, USA)., Results: LRRT treatment was performed in 34 eyes of 25 RP patients recruited for the study. The eyes were classified in two groups on the basis of foveal thickness (FT) assessed by SD-OCT: 14 eyes in Group A (FT≤190μm) and the remaining 20 ones in Group B (FT > 190μm). Although it had not reached the statistical significance, Group B showed a better improvement in BCVA, residual close-up visus and sensitivity than Group A., Conclusions: Previous studies have described the role of LRRT in slowing down retinal degenerative diseases. Consequently, this surgical procedure could improve the clinical and rehabilitative prognostic parameters in RP patients. On the other hand, further clinical research and studies with longer follow-up will be needed to evaluate its efficacy.

Purpose: Retinal prosthetic devices have been developed to partially restore very low vision in legally blind patients with end-stage hereditary retinal dystrophies. Subretinal implants, unlike epiretinal implants, are not fixated by a tack. The aim of this study was to assess and analyse possible changes over time in the subretinal position of the RETINA IMPLANT Alpha IMS and Alpha AMS (ClinicalTrials.gov NCT01024803)., Methods: Imaging studies were performed on fundus photographs using GIMP (Version 2.8.14). Postoperative photographs of the implanted eye were scaled and aligned. Landmarks were chosen and distances between landmarks were measured to then calculate the displacement of the microchip using a transformation matrix for rotational and translational movements. Analyses were performed using MATLAB 8.6 (The MathWorks Inc., Natick, MA)., Results: Of the 27 datasets with the Alpha IMS device, 12 (44%) remained stable without displacement of the microchip relative to the optic disc and the major blood vessels, whereas in 15 (56%), displacement occurred. The mean ± SD displacement in those 15 eyes was 0.66 ± 0.35 mm (range, 0.24-1.67 mm). Of the eight datasets with the Alpha AMS device, 1 (13%) remained stable without displacement of the microchip relative to the optic disc and the major blood vessels, whereas in 7 (87%), displacement occurred. The mean ± SD displacement in those seven eyes was 0.66 ± 0.26 mm (range, 0.32-0.97 mm). Calculated from all eyes (including those in which no displacement occurred), the mean displacement was 0.36 mm in the IMS cohort, and 0.58 mm in the AMS cohort, however, the difference was not statistically significant (p = 0.17)., Conclusions: We have shown that the position of the subretinal implant changes in the majority of the cases after implantation. While the overall mean displacement of the chip was not significantly different in either of the cohorts, the maximum displacement was smaller in the Alpha AMS cohort., (© 2019 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

The implantation of the Argus II retinal prosthesis system in a 54-year-old woman with retinitis pigmentosa who presented with an eye of long axial length at 26.82 mm was successful. Postoperative examination revealed a gap of 700 µm between the electrode array and the retina, which caused decreased visual perception. A modified strategy with quad and quinary electrode stimulation was introduced to generate higher perceptual thresholds. The patient experienced visual functional changes during the first half of the year after surgery, although no remarkable difference was observed in terms of implant-retina distance. Fibrosis around the tack developed and extended between the gap with the retina elevated from the tack toward the center array, 8 months after the surgery. Schisis of the retina developed and filled the gap, resulting in decreased threshold, and the strategy was then shifted back to single electrode stimulation mode. Rehabilitation program is an evolving process that depends on the distance between the array and the retina in the eye with staphyloma. This study first showed the implantation in a patient with high myopia who presented with long axial length after surgery and rehabilitation program in Taiwan.

Degenerative retinal diseases such as retinitis pigmentosa and macular degeneration cause irreversible vision loss in more than 10 million people worldwide. Retinal prostheses, now implanted in over 250 patients worldwide, electrically stimulate surviving cells in order to evoke neuronal responses that are interpreted by the brain as visual percepts ('phosphenes'). However, instead of seeing focal spots of light, current implant users perceive highly distorted phosphenes that vary in shape both across subjects and electrodes. We characterized these distortions by asking users of the Argus retinal prosthesis system (Second Sight Medical Products Inc.) to draw electrically elicited percepts on a touchscreen. Using ophthalmic fundus imaging and computational modeling, we show that elicited percepts can be accurately predicted by the topographic organization of optic nerve fiber bundles in each subject's retina, successfully replicating visual percepts ranging from 'blobs' to oriented 'streaks' and 'wedges' depending on the retinal location of the stimulating electrode. This provides the first evidence that activation of passing axon fibers accounts for the rich repertoire of phosphene shape commonly reported in psychophysical experiments, which can severely distort the quality of the generated visual experience. Overall our findings argue for more detailed modeling of biological detail across neural engineering applications.

Background and Objective: The authors describe a modified surgical technique for Argus II retinal prosthesis implantation., Patients and Methods: The modified surgical technique was performed in a 43-year-old male with retinitis pigmentosa (RP) who underwent strabismus surgery in that eye at age 8., Results: During Argus II implantation, the lateral rectus (LR) was noted to be 10 mm posterior to its original insertion due to prior strabismus surgery. The authors placed three 5-0 nylon mattress sutures at the expected location of the LR to support the external portion of the prosthesis, specifically the coil. The band was then passed through the mattress sutures, underneath the inferior, and medial recti with temporal placement of the coil., Conclusion: Placement of three mattress sutures allowed proper positioning of the device and enabled fixation of the suture tabs, thus minimizing the risk of postoperative conjunctival erosion and device exposure. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:116-119.]., (Copyright 2019, SLACK Incorporated.)

Purpose: To assess the retinal anatomy and array position in Argus II retinal prosthesis recipients., Design: Prospective, noncomparative cohort study., Methods: Setting: International multicenter study., Patients: Argus II recipients enrolled in the Post-Market Surveillance Studies., Procedures: Spectral-domain optical coherence tomography images collected for the Surveillance Studies (NCT01860092 and NCT01490827) were reviewed. Baseline and postoperative macular thickness, electrode-retina distance (gap), optic disc-array overlap, and preretinal membrane presence were recorded at 1, 3, 6, and 12 months., Main Outcome Measures: Axial retinal thickness and axial gap along the array's long axis (a line between the tack and handle); maximal retinal thickness and maximal gap along a B-scan near the tack, midline, and handle., Results: Thirty-three patients from 16 surgical sites in the United States and Germany were included. Mean axial retinal thickness increased from month 1 through month 12 at each location, but reached statistical significance only at the array midline (P = .007). The rate of maximal thickness increase was highest near the array midline (slope = 6.02, P = .004), compared to the tack (slope = 3.60, P < .001) or the handle (slope = 1.93, P = .368). The mean axial and maximal gaps decreased over the study period, and the mean maximal gap size decrease was significant at midline (P = .032). Optic disc-array overlap was seen in the minority of patients. Preretinal membranes were common before and after implantation., Conclusions: Progressive macular thickening under the array was common and corresponded to decreased electrode-retina gap over time. By month 12, the array was completely apposed to the macula in approximately half of the eyes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background and Objective: To investigate the predictive factors of visual acuity (VA) after cataract surgery in patients with retinitis pigmentosa (RP)., Patients and Methods: Retrospective, observational study. The authors reviewed a consecutive series of 70 patients (109 eyes) with RP who underwent cataract surgery. The changes in best-corrected visual acuity (BCVA) before and 3 months after surgery were measured. The relationship between preoperative ellipsoid zone (EZ) conditions, external limiting membrane (ELM) conditions, central macular thickness (CMT), and postoperative BCVA were investigated., Results: The mean BCVA was significantly improved after cataract surgery from 0.80 to 0.45 (P < .001). However, final BCVA did not improve in 57 eyes (52.3%). The mean postoperative BCVA was significantly better in eyes with an intact ELM than those without (P < .001), in eyes with an intact EZ than those without (P < .001), and in eyes with relatively normal CMT (≥ 200 μm) than those with decreased CMT (< 200 μm) (P < .001). In multiple linear regression analysis, preoperative logMAR VA (P < .001), ELM integrity (P < .001), and CMT (P = .017) remained the only three variables that were associated significiantly with postoperative BCVA (R 2 = 0.753; P < .001)., Conclusions: Postoperative BCVA in approximately half of the eyes was improved after cataract surgery in patients with RP. The preoperative BCVA and the status of ELM and CMT are important parameters to predict postoperative VA. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:587-594.]., (Copyright 2018, SLACK Incorporated.)

Objectives: To examine the effect of subthreshold diode micropulse laser (SDM) on pattern electroretinography (PERG) and visual function in retinitis pigmentosa (RP)., Methods: The records of all patients (pts) undergoing SDM in a vitreoretinal subspecialty practice were reviewed. Inclusion criteria included the presence of RP evaluated before and after SDM by PERG. As a secondary outcome measure, the results of automated omnifield resolution perimetry (ORP) were also reviewed., Results: All eyes undergoing SDM for RP were eligible study, including 26 eyes of 15 pts; seven male and eight female, aged 16-69 (avg. 47) years. Retinal function by PERG improved by all indices, with significant improvements in the 24° field signal latency measures; the MagD(µV)/ Mag(µV) ratio (P < 0.0001) and the MagD(µV) amplitude (P = 0.0003). ORP significantly improved by all indices (p = 0.02-0.002). Average best-corrected chart visual acuities improved from 0.6 to 0.4 logMAR units (p = 0.02). There were no adverse treatment effects., Conclusions: SDM significantly improved chart visual acuity, mesopic logMAR visual acuity perimetry, and retinal function by PERG in RP without adverse treatment effects. Treatment responses indicate a significant capacity for rescue of dysfunctional retina. These results suggest that early and periodic treatment with SDM might slow disease progression and reduce long-term vision loss.

Purpose of Review: The purpose of this review is to provide an update on the efforts to restore vision through subretinal implants in patients with degenerative retinal diseases. In addition to the current technique and its latest improvements, it will focus on the surgical technique of implantation as well as explantation and reimplantation., Recent Findings: The durability of the current subretinal implant RETINA IMPLANT Alpha AMS has increased substantially compared with the predecessor model RETINA IMPLANT Alpha IMS. According to validated examinations in the laboratory, a median lifetime of 4.7 years will be reached in clinical use; in similar examinations, the previous model has reached only 8 months. Visual function has slightly increased. The surgical technique for subretinal implants is complex and demanding for ophthalmic surgeons, as it is multifaceted and combines novel surgical steps in areas, which are not commonly entered such as the suprachoroidal and the subretinal space. The surgical approach for implantation has matured considerably and has led to successful implantation in 64 patient cases. Surgical challenges are now mainly encountered with the exact subfoveal positioning of the device. The explantation procedure is relatively straight-forward because the implant can be withdrawn in a reverse direction along the already existent subretinal path. Reimplantations, however, are more challenging because some degree of scar tissue may exist along the path of the chip and around the scleral trapdoor. Nevertheless, reimplantations have now been carried out successfully in four patients., Summary: The new RETINA IMPLANT Alpha AMS shows significantly improved durability compared with the predecessor model RETINA IMPLANT Alpha IMS. The subretinal implant offers excellent visual results but requires experienced surgeons. Explantation of devices is straight-forward, and reimplantations are challenging but have been successful in four patients.

Inherited or age-dependent retinal dystrophies such as Retinitis pigmentosa (RP) and macular degeneration (MD) are among the most prevalent causes of blindness. Despite enormous efforts, no established pharmacological treatment to prevent or cure photoreceptor degeneration has been identified. Given the relative survival of the inner retina, attempts have been made to restore vision with optogenetics or with retinal neuroprostheses to allow light-dependent stimulation of the inner retinal network. While microelectrode and photovoltaic devices based on inorganic technologies have been proposed and in many cases implanted in RP patients, a new generation of prosthetics based on organic molecules, such as organic photoswitches and conjugated polymers, is demonstrating an unexpected potential for visual rescue and intimate interactions with functioning tissue. Organic devices are starting a new era of tissue electronics, in which light-sensitive molecules and live tissues integrate and tightly interact, producing a new ecosystem of organic prosthetics and intelligent biotic/abiotic interfaces. In addition to the retina, the applications of these interfaces might be extended in the future to other biomedical fields.

Purpose: To report the initial efficacy results of the Retina Implant Alpha AMS (Retina Implant AG, Reutlingen, Germany) for partial restoration of vision in end-stage retinitis pigmentosa (RP)., Design: Prospective, single-arm, investigator-sponsored interventional clinical trial. Within-participant control comprising residual vision with the retinal implant switched ON versus OFF in the implanted eye., Participants: The Retina Implant Alpha AMS was implanted into the worse-seeing eye of 6 participants with end-stage RP and no useful perception of light vision. Eligibility criteria included previous normal vision for ≥12 years and no significant ocular or systemic comorbidity., Methods: Vision assessments were scheduled at 1, 2, 3, 6, 9, and 12 months postimplantation. They comprised tabletop object recognition tasks, a self-assessment mobility questionnaire, and screen-based tests including Basic Light and Motion (BaLM), grating acuity, and greyscale contrast discrimination. A full-field stimulus test (FST) was also performed., Main Outcome Measures: Improvement in activities of daily living, recognition tasks, and assessments of light perception with the implant ON compared with OFF., Results: All 6 participants underwent successful implantation. Light perception and temporal resolution with the implant ON were achieved in all participants. Light localization was achieved with the implant ON in all but 1 participant (P4) in whom the chip was not functioning optimally because of a combination of iatrogenic intraoperative implant damage and incorrect implantation. Implant ON correct grating detections (which were at chance level with implant OFF) were recorded in the other 5 participants, ranging from 0.1 to 3.33 cycles/degree on 1 occasion. The ability to locate high-contrast tabletop objects not seen with the implant OFF was partially restored with the implant ON in all but 1 participant (P4). There were 2 incidents of conjunctival erosion and 1 inferotemporal macula-on retinal detachment, which were successfully repaired, and 2 incidents of inadvertent damage to the implant during surgery (P3 and P4)., Conclusions: The Alpha AMS subretinal implant improved visual performance in 5 of 6 participants and has exhibited ongoing function for up to 24 months. Although implantation surgery remains challenging, new developments such as OCT microscope guidance added refinements to the surgical technique., (Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

The Argus II retinal prosthesis is the first commercially available device for restoration of vision in patients with Retinitis Pigmentosa or with similar retinal pathology who still have minimal residual native vision. The technology is able to restore vision with production of artificial visual percepts which usually are given adequate useful interpretation by the visual system in most implanted patients. The technology usually produces visual perception at the level of shape identification or better in some cases enabling in many less dependence on vision substitution devices and skills. There is no consensus among vision rehabilitation practitioners on single methods for assessments, outcome measures and training, yet there is constant progress in these areas of concern. Hence the current vision rehabilitation practice related to the implantation of the Argus II retinal prosthesis is a work in progress with many learning opportunities for all involved. All agree that implementation of this technology in clinical practice requires the combined work of a multi-disciplinary team which includes a specialized surgical team as well as a specialized rehabilitation team in order to obtain optimal results. Our own experience is presented in this paper and indicates so far that the Argus II technology is beneficial to patients and that it could be successfully managed within the Canadian heath care system., (Copyright © 2018 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Background and Objective: As an increasing number of vitreoretinal surgeons are implanting retinal prosthesis devices, the need to share surgical techniques to ease implantation in challenging scenarios grows. The authors share a technique to aide in overcoming a challenge associated with uveal prolapse in a patient undergoing Argus II retinal prosthesis (Second Sight Medical Products, Sylmar, CA) implantation., Patients and Methods: A surgical technique is discussed and demonstrated using a video (Video available at www.healio.com/OSLIRetina)., Results: A Sheets glide-assisted technique was used to successfully place the electrode array in the vitreous cavity., Conclusion: The Sheets glide may be a useful tool in aiding the retinal surgeon to successfully and easily place the electrode array of the Argus II retinal prosthesis. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:132-133.]., (Copyright 2018, SLACK Incorporated.)

Surgical restoration of vision with retinal prostheses is a new and developing technology currently available in a select group of countries, Canada among them. The Argus II retinal prosthesis is the first commercially available device for restoration of vision in patients with Retinitis Pigmentosa or with similar retinal pathology who still have minimal residual native vision. The surgery is complex and requires training however it is within the abilities of any experienced retina surgeon. Surgical experience builds up with each case and in our patients length of surgery constantly went down. Complications occurred however we experienced no catastrophic events. Most notable is that in our implanted cases the Argus II technology proved to be beneficial to most patients. In order to obtain optimal results with this surgical intervention it is absolutely required that the surgical work is complemented simultaneously with the work of a specialized rehabilitation team. A review of the technology, of our experience, comments and concerns is presented in this paper., (Copyright © 2018 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

A 58-year-old man with end-stage retinitis pigmentosa (RP) and visual acuity of light perception in both eyes received simultaneous phacoemulsification with intraocular lens implantation and implantation of the Argus II Retinal Prosthesis System (Second Sight Medical Products, Sylmar, CA) to his right eye 1 year ago. He accomplished the fitting and rehabilitation sessions, and no extraocular or intraocular complications were encountered perioperatively, postoperatively, or during the follow-up. The patient used the prosthesis actively for 2.5 to 3 hours per day. In this report, the authors compare the multimodal imaging findings including optical coherence tomography angiography of the chronic electrically stimulated retinal prosthesis implanted eye with the fellow eye. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:55-59.]., (Copyright 2018, SLACK Incorporated.)

A 62-year-old female who was legally blind secondary to retinitis pigmentosa (RP) developed new positive visual phenomena (PVP) ("visual storms") following implantation of the Argus II Retinal Prosthesis System (Second Sight Medical Products, Sylmar, CA). The potential mechanisms for the exacerbating PVP or hallucinatory release phenomena are proposed. Clinicians should be aware of these visual phenomena in patients with RP and the potential for worsening of or de novo development of PVP in patients considering the Argus II implant. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:1022-1025.]., (Copyright 2017, SLACK Incorporated.)

Retinitis pigmentosa and age-related macular degeneration are two significant causes of severe visual dysfunction. In both, the retinal photoreceptors degenerate, preventing successful conversion of light into electrical energy that is interpreted in the visual cortex as visual function. Artificial vision or visual function began over two centuries ago with the idea of creating artificial light pulses, or phosphenes, through cortical stimulation. The pursuit is now on to improve artificial visual function. Two retinal implants appear the most likely to succeed in the future having undergone multicentre human trials: the Argus II electronic epiretinal device (Second Sight Medical Products, CA, USA) and Alpha-IMS electronic subretinal device (Retina Implant AG, Germany). The trial results to date are encouraging with visual improvement and acceptable safety profiles reported for both devices. At present, the visual function generated by either device does not offer high enough resolution or acuity for a patient to regain a fully functional life. Despite this, both devices not only have the potential, but have actually improved the vision-related quality of life in a significant number of patients implanted. With this in mind, the economic argument is clear. Provided device-life is long enough, its cost should be acceptable for the obtained improvement in the quality of life. The aim of this Review Article is to assist those readers that may be considering offering any of these devices as a treatment for blindness in Retinitis Pigmentosa.

Purpose: Retinal prostheses provide vision to blind patients by eliciting phosphenes through electrical stimulation. This study explored whether character identification and image localization could be achieved through direct multiple-electrode stimulation with a suprachoroidal retinal prosthesis., Methods: Two of three retinitis pigmentosa patients implanted with a suprachoroidal electrode array were tested on three psychophysical tasks. Electrode patterns were stimulated to elicit perception of simple characters, following which percept localization was tested using either static or dynamic images. Eye tracking was used to assess the association between accuracy and eye movements., Results: In the character identification task, accuracy ranged from 2.7% to 93.3%, depending on the patient and character. In the static image localization task, accuracy decreased from near perfect to <20% with decreasing contrast (patient 1). Patient 2 scored up to 70% at 100% contrast. In the dynamic image localization task, patient 1 recognized the trajectory of the image up to speeds of 64 deg/s, whereas patient 2 scored just above chance. The degree of eye movement in both patients was related to accuracy and, to some extent, stimulus direction., Conclusions: The ability to identify characters and localize percepts demonstrates the capacity of the suprachoroidal device to provide meaningful information to blind patients. The variation in scores across all tasks highlights the importance of using spatial cues from phosphenes, which becomes more difficult at low contrast. The use of spatial information from multiple electrodes and eye-movement compensation is expected to improve performance outcomes during real-world prosthesis use in a camera-based system. (ClinicalTrials.gov number, NCT01603576.).

A 44-year-old Saudi female presented with poor right eye vision for 3 years. Visual acuity (VA) was 20/400 in the right eye and 20/20 in the left eye. Examination and imaging showed all the typical features of retinitis pigmentosa in the right eye associated with full thickness macular hole (FTMH) and an essentially normal left eye. The case underwent pars plana vitrectomy with internal limiting membrane peeling and gas tamponade that resulted in anatomical closure of the FTMH, but VA remained the same., Competing Interests: There are no conflicts of interest.