Retinal Prosthesis Implantation Research Articles

Surgical Observations From the First 120 Cases of Subretinal Gene Therapy for Inherited Retinal Diseases.

To report surgical observations formulated during the first 120 cases of subretinal gene therapy in patients with inherited retinal degenerations (IRDs). A two-surgeon team compiled surgical observations and formulated surgical pearls based on the consecutive cases of subretinal viral vector injection in patients enrolled in clinical trials focusing on choroideremia, achromatopsia, and RP GTPase regulator associated retinitis pigmentosa, as well as patients with retinal pigment epithelium-specific-65-kDa (RPE65) associated Leber congenital amaurosis receiving Food and Drug Administration-approved voretigene neparvovec-rzyl therapy. One hundred twenty subretinal surgeries were performed by a two-surgeon team. Key anatomical features pertinent to surgical management were noted and are described in this article. Surgical decision making for successful subretinal administration of viral vectors and management of potential surgical challenges were formulated. Lessons learned during subretinal gene therapy cases may be helpful to other surgeons entering clinical trials or performing postapproval gene therapy administration. Surgical pearls outlined in this article may also be helpful for other targeted subretinal therapies, such as cellular transplantation or retinal prosthesis implantation.

Long term positional stability of the Argus II retinal prosthesis epiretinal implant

BackgroundThe 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.MethodsFive 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.ResultsThere 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 (\U0001d6fe) (M1 to M24) (F = 3.527, p = 0.030). There was no significant change in angle \U0001d71f (the angle to the horizontal of the image), angle \U0001d736 (tack-optic disc-surgical handle), and angle \U0001d737 (optic-disc-surgical handle-tack).ConclusionOur 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.

Evaluation of the Long-Term Clinical Results of 3 Patients Implanted with the Argus II Retinal Prosthesis.

This study presents the long-term clinical results of Argus II retinal prosthesis implantation in eyes with light perception and projection in 3 patients with end-stage retinitis pigmentosa. No conjunctival erosion, hypotony, or implant displacement was observed during postoperative follow-up. The electrical threshold values were lower in the macular region and higher close to the tack fixation region and peripherally. Optical coherence tomography scans showed fibrosis and retinoschisis formation at the retina-implant interface in two cases. This was attributed to mechanical and electrical effects on the tissue due to the active daily use of the system and the electrodes' proximity to the retina. The patients were able to integrate the system into their daily lives and perform activities that they could not do before. Studies on retinal prostheses for the rehabilitation of hereditary retinal diseases are ongoing, so both social and clinical observations and experiences related to the implant are valuable.

Visual Rehabilitation After Retinal Prosthesis Implantation: An 18-month Case Report, From Candidate Selection to Follow-Up

Introduction: Various retinal implants are being developed and appear to be a promising option for improving the visual capacities of individuals with retinal dystrophy. A multidisciplinary approach to both assessment of a candidate’s factors and rehabilitation could contribute to improved activity and participation. The purpose of this study was (i) to document the approach taken by a multidisciplinary team in the candidate selection process and in training in the use of the Argus II retinal prosthesis system (RPS), and (ii) to examine the effects of the RPS on sensory and mental functions and on activity and participation. Methods: An A1-B1-A2-B2 experimental case report was used, with repeated measures pre- and post-rehabilitation program design. The A phases represent the periods with the system off, whereas the B phases represent the periods with the system on. A 65-year-old man with retinitis pigmentosa and total blindness was followed by a multidisciplinary team for over 18 months. After receiving the retinal implant, he benefited from a 10-week rehabilitation program (twice per week; B1 phase). Results: Globally, the RPS improved vision in the B phases when the system was on and visual acuity was stable at 2.3 logMAR (functional blindness). The participant’s mental and neuromusculoskeletal function scores were generally stable throughout the data collection periods. Lower performance on some measures at the end of phase B2 coincided with a negative mood. Discussion: Use of the RPS improved activity, but this did not transfer into greater participation in the living environment. Despite efforts made by the rehabilitation team to manage the user’s expectations concerning the RPS, the interventions reactivated his grieving over his vision loss. Implications for Practitioners: New technologies can make users dream of unrealistic possibilities, and managing their expectations requires problem solving supported by a multidisciplinary team.

New epiretinal implant with integrated sensor chips for optical capturing shows a good biocompatibility profile in vitro and in vivo

BackgroundRetinal 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.ResultsThe 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.ConclusionsThe 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.

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

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.

岡山大学方式人工網膜(OUReP)を網膜下に植込む使い捨て注入器(OUReP Injector)作成とウサギ模擬試験

岡山大学方式人工網膜(OUReP)を網膜下に植込む使い捨て注入器(OUReP Injector)作成とウサギ模擬試験

The Argus-II Retinal Prosthesis Implantation; From the Global to Local Successful Experience.

Over the past few years, visual prostheses (namely, Argus II retinal implant) and gene therapy have obtained FDA approval in treating blindness resulting from retinitis pigmentosa. Compared to gene therapy; Argus II is less costly with a demonstrated favorable outcome, though the vision is yet artificial. To obtain better results, expectation counseling and preoperative retinal assessment are critical. The global experience with Argus II has enrolled no more than 300 cases so far. The first Argus II retinal prosthesis in Iran was successfully implanted in Shiraz (October 2017). To date, Argus II artificial retina is implanted in four patients in Iran. Beside successful surgery and post-operative care, rehabilitation efforts with validated outcome measures including visual rehabilitation together with neurovisual, visuo-constructive and cognitive rehabilitation/empowerment approaches are expected to boost the functional outcome. A multidisciplinary approach within a cross-functional team would optimize strategies toward better patient outcomes. As such, establishing a collaborative network will foster organized research efforts to better define outcome assessment and rehabilitation strategies. This technology report paper has been an attempt to provide an overview of Argus-II retinal implant global experience as well as the clinical outcome of the so far cases in Iran. Insights from this report were communicated during the first “Brain Engineering and Computational Neuroscience Conference,” 31 January-2 February 2018 in Tehran.

Investigation of Surgical Techniques for Optimization of Long-Term Outcomes of LCP-Based Retinal Prosthesis Implantation.

PurposeTo investigate reproducible surgical techniques to optimize the long-term safety of liquid crystal polymer (LCP)-based retinal prosthesis implantation.MethodsAn LCP-based retinal prosthesis is fabricated monolithically on a single-body LCP substrate with all components, including the package and electrode array. We implanted the electrode array into the suprachoroidal space and anchored the package and transition part to the sclera in rabbits (n = 11). The safety profile was assessed upon the completion of the surgery and postoperatively.ResultsThe surgical procedures for implantation of the entire system were easily performed in nine eyes (81.8%) without any intraoperative complications. In the other two eyes (18.2%), surgical complications related to electrode insertion, including optic nerve damage and retinal tear, arose. In 10 eyes (90.9%), the devices were well tolerated for at least 3 months. However, in most eyes (nine; 81.8%), two complications began to appear after 3 months, postoperatively, including conjunctival erosion or dehiscence over the package or transition part. The electrode arrays were maintained safely in the suprachoroidal space after surgery without any complications, regardless of the status of the extraocular components in all cases except two intraoperative complications.ConclusionsWe established safe and reproducible surgical techniques for implantation of our LCP-based retinal prosthesis into the suprachoroidal space. Although issues related to surgical technique or device configuration were identified, further technical solutions would improve the long-term safety of device implantation.Translational RelevanceThis study presents successful implantation of LCP-based retinal prosthesis. The technical solutions will permit an optimization of surgical techniques.

Sheets Glide-Assisted Intraocular Placement of the Argus II Retinal Prosthesis.

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. A surgical technique is discussed and demonstrated using a video (Video available at www.healio.com/OSLIRetina). A Sheets glide-assisted technique was used to successfully place the electrode array in the vitreous cavity. 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.].

Gene Therapy, Stem Cell Treatment and Retinal Implant in Dry-Form (Non-Neovascular) Age-Related Macular Degeneration

Nowadays there is no treatment option except antioxidant support which decelerates the progression of dry-type age-related macular degeneration (ARMD) which is one of the most common reasons for legal blindness in elderly people. Promising outcomes have been obtained with stem cell treatment and gene therapy in dry-type ARMD in the recent studies which are done in the light of the advanced bioengineering developments. In addition, very rapid advances have been developing related to the retinal prosthesis implantation which is performed to regain their functional vision in end-stage ARMD patients.

Visual evoked potential in RCS rats with Okayama University-type retinal prosthesis (OUReP\u2122) implantation

Photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. The dye-coupled films or plain films were implanted subretinally in both eyes of 10 Royal College of Surgeons rats with hereditary retinal dystrophy at the age of 6 weeks. Visual evoked potentials in response to monocular flashing light stimuli were recorded from cranially-fixed electrodes, 4 weeks and 8 weeks after the implantation. After the recording, subretinal film implantation was confirmed histologically in 7 eyes with dye-coupled films and 7 eyes with plain films. The recordings from these 7 eyes in each group were used for statistical analysis. The amplitudes of visual evoked potentials in the consecutive time points from 125 to 250 ms after flash were significantly larger in the 7 eyes with dye-coupled film implantation, compared to the 7 eyes with plain film implantation at 8 weeks after the implantation (P < 0.05, repeated-measure ANOVA). The photoelectric dye-coupled polyethylene film, as retinal prosthesis, gave rise to visual evoked potential in response to flashing light.

Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up.

IntroductionThe Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy. During implantation, the manufacturer recommends to cover the sclerotomy site with a patch of processed human pericardium to prevent postoperative hypotony and conjunctival erosion by the underlying electronics case. Due to biomedical regulations prohibiting the use of this material in France, we developed an alternative technique combining a scleral flap protecting the sclerotomy and an autogenous graft of superior temporalis fascia overlying the electronics case.MethodsThe purpose of this study is to describe the 4-year outcomes of this modified procedure in three subjects who underwent Argus II Retinal Prosthesis System implantation. Clinical data consisting of intraocular pressure measurements and tolerance in terms of conjunctival erosion or inflammation were retrospectively assessed over a 4-year postoperative follow-up.ResultsNone of the three patients implanted with the modified technique developed ocular hypotony over 4 years. A normal, transient conjunctival inflammation occurred during the first postoperative month but conjunctival erosion was not observed in any of the three patients over 4 years. Four years after implantation, the autogenous temporalis fascia graft remained well tolerated and the retinal prosthesis was functional in all three patients.ConclusionThe combination of an autograft of superficial temporalis fascia and a scleral flap efficiently prevented leakage through the sclerotomy site, ocular hypotony, and conjunctival erosion by the extrascleral electronics case. This modified technique is suitable for the implantation of existing and forthcoming retinal prostheses. Superficial temporalis fascia may also be used as alternative to commercial tectonic tissues for scleral wound repair in clinical settings where they are not available.

Assistive peripheral phosphene arrays deliver advantages in obstacle avoidance in simulated end-stage retinitis pigmentosa: a virtual-reality study

Objective. The prospective efficacy of peripheral retinal prostheses for guiding orientation and mobility in the absence of residual vision, as compared to an implant for the central visual field (VF), was evaluated using simulated prosthetic vision (SPV). Approach. Sighted volunteers wearing a head-mounted display performed an obstacle circumvention task under SPV. Mobility and orientation performance with three layouts of prosthetic vision were compared: peripheral prosthetic vision of higher visual acuity (VA) but limited VF, of wider VF but limited VA, as well as centrally restricted prosthetic vision. Learning curves using these layouts were compared fitting an exponential model to the mobility and orientation measures. Main results. Using peripheral layouts, performance was superior to the central layout. Walking speed with both higher-acuity and wider-angle layouts was 5.6% higher, and mobility errors reduced by 46.4% and 48.6%, respectively, as compared to the central layout. The wider-angle layout yielded the least number of collisions, 63% less than the higher-acuity and 73% less than the central layout. Using peripheral layouts, the number of visual-scanning related head movements was 54.3% (higher-acuity) and 60.7% (wider-angle) lower, as compared to the central layout, and the ratio of time standing versus time walking was 51.9% and 61.5% lower, respectively. Learning curves did not differ between layouts, except for time standing versus time walking, where both peripheral layouts achieved significantly lower asymptotic values compared to the central layout. Significance. Beyond complementing residual vision for an improved performance, peripheral prosthetic vision can effectively guide mobility in the later stages of retinitis pigmentosa (RP) without residual vision. Further, the temporal dynamics of learning peripheral and central prosthetic vision are similar. Therefore, development of a peripheral retinal prosthesis and early implantation to alleviate VF constriction in RP should be considered to extend the target group and the time of benefit for potential retinal prosthesis implantees.

Assistive peripheral prosthetic vision aids perception and mobility in outdoor environments: A virtual-reality simulation study.

Retinitis pigmentosa (RP) causes visual field (VF) constriction due to progressive loss of photoreceptors, typically from the retinal periphery to the fovea. Retinal prostheses offer vision restoration via electrode implantation and stimulation near the fovea, thereby eliciting articifial percepts, so-called phosphenes in the center VF. Although foveal photoreceptors can persist for prolonged periods of time, bionic therapy is usually restricted to stages of RP with complete vision loss. However, persons with RP experience mobility impairment from peripherally restricted VFs much earlier. Consequently, the amount of visual scanning necessary for navigation is increased, and maintaining a steady pace is challenging. Receiving a retinal implant at this early stage might be feasible. We investigated the potential of a peripheral visual prosthesis coexisting with central residual vision to facilitate scene perception and mobility. Simulating prosthetic and residual vision in a virtual mobility environment, we found that assistive phosphene layouts were associated with reductions in visual scanning-related head movements of up to 42.1%, body rotations of up to 30%, and up to 45% lower frequency of stopping when circumventing low-lying obstacles, pedestrians and following a path. Further research on early implantation of retinal prostheses for the peripheral VF is therefore advised.

Vision maintenance and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation.

Photoelectric dye-coupled polyethylene film, designated Okayama University-type retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. In this study, the vision was assessed by behavior tests in aged hereditary retinal dystrophic RCS rats with OUReP™, retinal apoptosis and electroretinographic responses were measured in dystrophic eyes with OUReP™. The dye-coupled films, or plain films as a control, were implanted in subretinal space of RCS rats. On behavior tests, RCS rats with dye-coupled films, implanted at the old age of 14weeks, showed the larger number of head-turning, consistent with clockwise and anticlockwise rotation of a surrounding black-and-white-striped drum, compared with rats with plain films, under the dim (50 lux) and bright (150 lux) conditions in the observation period until the age of 22weeks (n=5, P<0.05, repeated-measure ANOVA). The number of apoptotic cells in retinal sections at the site of dye-coupled film implantation was significantly smaller, compared with the other retinal sites, neighboring the film, or opposite to the film, 5months after film implantation at the age of 6weeks (P=0.0021, Friedman test). The dystrophic eyes of RCS rats with dye-coupled films showed positive responses to maximal light stimulus at a significantly higher rate, compared with the eyes with no treatment (P<0.05, Chi-square test). Electroretinograms in normal eyes of Wistar rats with dye-coupled or plain films showed significantly decreased amplitudes (n=14, P<0.05, repeated-measure ANOVA). In conclusions, vision was maintained in RCS rats with dye-coupled films implanted at the old age. The dystrophic eyes with dye-coupled films showed electroretinographic responses. Five-month film implantation caused no additional retinal changes.

Optical imaging of visual cortical responses evoked by transcorneal electrical stimulation with different parameters.

The use of phosphenes evoked by transcorneal electrical stimulation (TcES) has been proposed as a means of residual visual function evaluation and candidate selection before implantation of retinal prostheses. Compared to the subjective measures, measurement of neuronal activity in visual cortex can objectively and quantitatively explore their response properties to electrical stimulation. The purpose of this study was to investigate systematically the properties of cortical responses evoked by TcES. The visual cortical responses were recorded using a multiwavelength optical imaging of intrinsic signals (OIS) combining with electrophysiological recording by a multichannel electrode array. The effects of different parameters of TcES on cortical responses, including the changes of hemoglobin oxygenation and cerebral blood volume, were examined. We found consistent OIS activation regions in visual cortex after TcES, which also showed strong evoked field potentials according to electrophysiological results. The OIS response regions were located mainly in cortical areas representing peripheral visual field. The extent of activation areas and strength of intrinsic signals were increased with higher current intensities and longer pulse widths, and the largest responses were acquired in the frequency range 10 to 20 Hz. Use of TcES through the ERG-jet corneal electrode may preferentially activate peripheral retina. Revealing the hemodynamic changes in visual cortex occurred after electrical stimulation can contribute to comprehension of neurophysiological underpinnings underlying prosthetic vision. This study provided an objective foundation for optimizing parameters of TcES and would bring considerable benefits in the application of TcES for assessment and screening in patients.

Development of a surgical procedure for implantation of a prototype suprachoroidal retinal prosthesis

BackgroundCurrent surgical techniques for retinal prosthetic implantation require long and complicated surgery, which can increase the risk of complications and adverse outcomes.MethodThe suprachoroidal position is known to be an easier location to access surgically, and so this study aimed to develop a surgical procedure for implanting a prototype suprachoroidal retinal prosthesis. The array implantation procedure was developed in 14 enucleated eyes. A full-thickness scleral incision was made parallel to the intermuscular septum and superotemporal to the lateral rectus muscle. A pocket was created in the suprachoroidal space, and the moulded electrode array was inserted. The scleral incision was closed and scleral anchor point sutured. In 9 of the 14 eyes examined, the device insertion was obstructed by the posterior ciliary neurovascular bundle. Subsequently, the position of this neurovascular bundle in 10 eyes was characterized. Implantation and lead routing procedure was then developed in six human cadavers. The array was tunnelled forward from behind the pinna to the orbit. Next, a lateral canthotomy was made. Lead fixation was established by creating an orbitotomy drilled in the frontal process of the zygomatic bone. The lateral rectus muscle was detached, and implantation was carried out. Finally, pinna to lateral canthus measurements were taken on 61 patients in order to determine optimal lead length.ResultsThese results identified potential anatomical obstructions and informed the anatomical fitting of the suprachoroidal retinal prosthesis.ConclusionAs a result of this work, a straightforward surgical approach for accurate anatomical suprachoroidal array and lead placement was developed for clinical application.

The use of an axisymmetric formulation of the Finite Volume Method for the thermal analysis of the retina and ocular tissues following implantation of retinal prosthesis

This study analyzes the heat transfer in human eyes following implantation of retinal prostheses using an axisymmetric formulation of the Finite Volume Method. The model used consisted of a vertex centered unstructured grid finite volume method in an edge-based data structure and an explicit time integration. The results of the finite volume thermal analysis in ocular tissues were determined in the presence of two types of retinal implants: subretinal and epiretinal. For the subretinal device, the maximum temperature reached in the retina was 36.78°C (309.78 K) and the irreversible thermal damage occurred at 200 days. In the case of the epiretinal implant, the maximum temperature reached at the retinal/chip interface was 36.92°C (309.92 K) and the irreversible thermal damage occurred at 180 days. Our results indicate that tin spite of its higher dissipation power, the epiretinal implant produces thermal damages similar to that caused by the subretinal implant. The computational tool which was developed was able to effectively calculate temperature profiles and thermal damage values to retinal implants and is also capable to calculate temperature profile in any other geometry of interest, for example with other types s of external thermal source like laser beans.

Optical coherence tomographic parameters as objective signs for visual acuity in patients with retinitis pigmentosa, future candidates for retinal prostheses

To find optical coherence tomographic parameters related with visual acuity, and, thus, which might be used as objective signs to predict visual acuity after future treatment, for example retinal prosthesis implantation, 86 eyes of 45 consecutive patients with retinitis pigmentosa, who showed no macular diseases, underwent optical coherence tomography to measure macular retinal thickness and peripapillary retinal nerve fiber layer (RNFL) thickness, and to obtain horizontal cross-sectional images at the fovea for observation of the inner segment/outer segment (IS/OS) junction line. Best-corrected visual acuity was significantly better either in the right eyes or in the left eyes with greater retinal thickness of all four quadrants of the macular area in the inner ring, encompassing 1-3mm from the foveal center (P<0.05, Spearman rank correlation test), and also with the presence of the IS/OS line at the fovea (P<0.0001, Wilcoxon-Kruskal-Wallis rank sum test). Retinal average thickness in the posterior pole covering the 6×6mm square area was positively correlated with peripapillary RNFL average thickness either in the right eyes or in the left eyes (P<0.05). The average thickness of the peripapillary RNFL became significantly less with age (P<0.05), but was not related with visual acuity. Macular retinal thickness and the presence of the IS/OS line, but not peripapillary RNFL thickness, could serve as objective signs for better visual acuity in retinitis pigmentosa. The macular retinal thickness might be used as an objective predictor to choose patients with retinitis pigmentosa who would be expected to gain vision after retinal prosthesis implantation.