Photovoltaic, wireless wide-field epiretinal prosthesis to treat retinitis pigmentosa.

PURPOSE: To develop and evaluate a photovoltaic, wireless wide-field epiretinal prosthesis for the treatment of retinitis pigmentosa. METHODS: A mosaic array of thinned silicon-based photodiodes with integrated thin-film stimulation electrodes was fabricated with a flexible polyimide substrate film to form a film-based miniaturized electronic system with wireless optical power and signal transmission and integrated electrostimulation. Manufactured implants were characterized with respect to their optoelectronic performance and biocompatibility following DIN EN ISO 10993. RESULTS: A 14 mm diameter prosthesis containing 1276 pixels with a maximum sensitivity at a near infrared wavelength of 905 nm and maximized stimulation current density 30-50 µm below the electrodes was developed for direct activation of retinal ganglion cells during epiretinal stimulation. Fabricated prostheses demonstrated mucosal tolerance and the preservation of both metabolic activity, proliferation and membrane integrity of human fibroblasts as well as the retinal functions of bovine retinas. Illumination of the prosthesis, which was placed epiretinally on an isolated perfused bovine retina, with infrared light resulted in electrophysiological recordings reminiscent of an a-wave (hyperpolarization) and b-wave (depolarization). CONCLUSIONS: A photovoltaic, wireless wide-field epiretinal prosthesis for the treatment of retinitis pigmentosa using near infrared light for signal transmission was designed, manufactured and its biocompatibility and functionality demonstrated in vitro and ex vivo.

Vision loss associated with silicone oil endotamponade in vitreoretinal surgery - a review.

PURPOSE: To clarify the definition, prevalence and classification of different types of unexplained vision loss associated with silicone oil (SO) endotamponades (SO in situ (SOIS) or after removal of SO (ROSO)) in vitreoretinal surgery and identifying the most specific clinical findings and suggesting possible causes. METHODS: Review of the literature regarding randomized clinical trials (RCTs), retrospective case-control, cohort studies and case series evaluating the risk of using SO, published in English between 1994 and 2023, conducting a computer-based search of the following databases: PubMed, Web of Science, Scopus and Embase. The search was supplemented using the Medline option 'Related Articles' and consulting review articles on the topic. RESULTS: Findings from reported clinical examinations in SOIS and ROSO are analyzed and finally different theories regarding the underlying pathophysiology are described. From the clinical point of view, findings have been found in OCT, OCTA, microperimetry and electrophysiological studies. Other clearly identifiable causes of vision loss related to the use of SO are listed and commented as differential diagnosis. Finally, the different physiopathological theories of the two types of causes of unexplained vision have been analyzed. CONCLUSION: Unexpected vision loss under or after SO tamponade (SOIS and ROSO) is a significant concern which is probably underestimated because it is not a clearly defined and known entity. The most frequently described changes were in the ganglion cell complex but this unexpected vision loss remains a serious and unexplained concern for vitreoretinal surgeons and should be identified by clinicians, addressed by manufacturers and reported to Health Authorities as a serious incident according to the new regulation.

Web-based Telemonitoring of Visual Function and Self-reported Postoperative Outcomes in Cataract Care: an International Multicenter RCT.

PURPOSE: Comparing web-based, self-administered follow-up after cataract surgery to conventional face-to-face follow-up. SETTING: Eye clinics in the Netherlands, Austria and Germany. DESIGN: Randomized controlled trial with an embedded method comparison study [ClinicalTrials.gov: NCT04809402]. METHODS: Routine cataract patients were randomized into two groups: the 'telemonitoring' group undertook web-based vision self-assessments and questionnaires from home, while the 'usual care' group received conventional care. All participants had a 4-6 week post-surgery clinic visit for safety and validation purposes. Outcomes included: the web-test's accuracy for assessing postoperative visual acuity (VA) and refractive error; adverse event rates; and patient reported outcome measurements (PROMs). RESULTS: 94 participants (188 eyes) were enrolled. Web-based uncorrected distance VA testing demonstrated a negligible mean difference (-0.03±0.14 logMAR) when compared to conventional ETDRS chart testing, with 95% limits-of-agreement ranging from -0.30 to 0.24 logMAR. The web-based refraction assessment overestimated the postoperative refractive error (mean difference 0.15±0.67 diopters), resulting in a poorer corrected distance VA compared to subjective refraction (mean 0.1 vs. -0.1 logMAR). Rates of adverse events and unscheduled consultations were minimal across both groups. Preoperative and postoperative PROMs questionnaires had a 100% response rate. Visual functioning (Catquest-9SF and NEI-VFQ-25) improved after surgery (mean improvement -0.80 and 16.70 respectively) and did not significantly differ between the two groups. CONCLUSION: The cataract patients in this study effectively provided postoperative outcome data via a web-interface. Both conventional and web-based follow-ups yielded similar PROMs and adverse event rates. Future developments should reduce the variability in the web-based VA test and yield representative refraction outcomes.

Clinical Experience of Two Sutureless Intrascleral Fixation Techniques for Secondary Intraocular Lens Implantation.

INTRODUCTION: The aim of this study was to evaluate the outcome of the modified Carlevale intraocular lens (IOL) fixation technique, using two different vitrectomy ports (23- vs. 27-gauge) as anchor fixation. METHODS: Retrospective, consecutive study of 282 eyes (282 patients) who underwent a secondary IOL implantation using the Carlevale IOL (Soleko IOL Division, Italy) with two anchor haptics for intrascleral implantation with either 23- or 27-gauge (G) port. RESULTS: Transient post-operative ocular hypotonia (intraocular pressure ≤5 mm Hg) was observed less in the 27-G group (13 vs. 4 patients, p = 0.057) three requiring additional tunnel sutures (2 cases for 23-G; 1 case 27-G). Post-operative vitreous haemorrhage was recorded more often in the 23-G group (8 vs. 1 patient, p = 0.034), but all cases in both groups resolved without intervention. Visual acuity did improve post-operatively in the two groups. No post-operative complications such as retinal detachment, endophthalmitis, and IOL-dislocation tilt were observed in the follow-up. CONCLUSION: The 27-G modified technique for sutureless intrascleral implantation is simple and effective and causes less post-operative hypotony.

Safety and performance assessment of hyaluronic acid-based vitreous substitutes in patients with phthisis bulbi.

PURPOSE: To assess the safety and performance of hyaluronic acid-based vitreous substitutes in phthitic eyes. METHODS: In this retrospective interventional study a total of 21 eyes from 21 patients with phthisis bulbi were treated at the Eye Clinic Sulzbach between August 2011 and June 2021. Patients who underwent a 23G pars plana vitrectomy received a vitreous substitute composed of (I) a non-crosslinked hyaluronic acid (Healon GV), (II) a crosslinked hyaluronic acid-based hydrogel (UVHA), or (III) silicone oil (SO-5000). Main outcome measures were the intraocular pressure (IOP), the visual acuity and the structural integrity of the retina and choroid assessed by optical coherence tomography. RESULTS: An increase in IOP ≥ 5 mmHg was achieved with SO-5000 in 5/8 eyes (6/10 interventions, 60.0%) for 36.4 ± 39.5 days, with Healon GV in 4/8 eyes (7/11 interventions, 63.6%) for 82.6 ± 92.5 days and with UVHA in 4/5 eyes (5/6 interventions, 83.3%) for 93.6 ± 92.5 days. Visual acuity increased in 5/21 eyes (23.8%), remained constant in 12/21 eyes (57.1%) and decreased in 4/21 eyes (19.0%). No enucleations were required during the mean follow-up time of 192 ± 182 days. The OCT images indicated the preservation of retinal structures, while choroidal folds were only diminished in UVHA eyes. CONCLUSIONS: Hyaluronic acid-based hydrogels are biocompatible vitreous substitutes in humans and can increase and stabilize IOP in patients with phthisis bulbi for about 3 months.

Gamification to Support Adherence to a Therapeutic Ambylopia Treatment for Children: Retrospective Study Using a Focal Ambient Visual Acuity Stimulation Game.

BACKGROUND: The gold standard treatment for amblyopia is patching the better eye. Improvement of visual acuity in the amblyopic eye is significantly impacted by the adherence to the patching therapy. It is known that the overall adherence is rather low. OBJECTIVE: This retrospective study evaluated whether an updated version of attention-binding digital therapeutic games based on the principle of focal ambient visual acuity stimulation (FAVAS) would result in improved patient adherence in 4- to 16-year-old patients with amblyopia associated with anisometropia or strabismus. METHODS: We analyzed electronically pseudonymized recorded data from patients treated with occlusion therapy and FAVAS therapeutic games. One group used an older version (2015) and the other group used a newer version (2020) that provided more attractive therapeutic games with tablet computer functionality. Objective adherence was calculated by comparing the number of minutes using the therapeutic games as monitored in the automatized logbook versus the prescribed number of minutes for using the games. RESULTS: Children in group 2015 (n=138) spent on average 2009.3 (SD 1372.1; range 36-5556) minutes using FAVAS; children in group 2020 (n=129) spent on average 2651.2 (SD 1557.1; range 38-5672) minutes using the newer version. Group 2020 spent on average 641.9 more minutes on FAVAS than group 2015 (t255.49=3.56, P<.001, d=0.45; 95% CI 0.69-0.20). Although patient adherence was very variable, compared to the 55.0% (SD 29.4%) in group 2015, it significantly improved up to 68.5% (SD 33.7%) in group 2020 (t254.38=3.48, P=.001, d=0.44; 95% CI 0.68-0.19). CONCLUSIONS: FAVAS 2020, with improved gamification aspect as well as tablet computer functionality, increased adherence significantly compared to the earlier version of FAVAS 2015, indicating that FAVAS 2020 could be an effective approach to support adherence to amblyopia treatment. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00017633; https://drks.de/search/de/trial/DRKS00017633.

Efficacy of a new fragmentation pattern in femtosecond laser-assisted cataract surgery with the Ziemer FEMTO LDV Z8.

PURPOSE: To determine the efficacy of different fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS) using Ziemer FEMTO LDV Z8. METHODS: We compared three different types of surgery: conventional cataract surgery (CCS), FLACS with conventional radial slices (named No-Spiderweb), and FLACS with a novel fragmentation pattern (radial slices combined with one or two rings) called "Spiderweb." Visual acuity (VA), nuclear opacity (NO) according to the Lens Opacities Classification System (LOCS lll), effective phacoemulsification time (EPT) and vacuum time were obtained for 845 eyes. RESULTS: Using FLACS (Spiderweb + No-Spiderweb), EPT was significantly reduced by 26% compared to CCS (FLACS: 2.46 ± 2.60 s; CCS: 3.34 ± 2.89 s; ΔM = - 0.88 s, p < .001). Furthermore, EPT as a function of progression of lens opacity was found to be not only lower in Spiderweb compared to CCS, but also in comparison with No-Spiderweb. At NO3, a significant reduction of 65% in EPT was observed by using Spiderweb compared to CCS (Spiderweb: 0.68 ± 1.23 s; CCS: 1.96 ± 1.53 s; ΔM = - 1.28 s, p <.001). Interestingly, EPT at NO3 was also significantly reduced by 57% in Spiderweb compared to No-Spiderweb (Spiderweb: 0.68 ± 1.23 s; No-Spiderweb: 1.57 ± 1 .59 s; ΔM = - 0.90 s, p <.001). The use of Spiderweb only marginally extends the vacuum time compared to No-Spiderweb by 11 s (Spiderweb: 209.13 ± 35.83 s; No-Spiderweb: 198.35 ± 36.84 s; p = .003) and the postoperative improved VA showed no significant difference among the different types of surgery (all ps ≥ .05). CONCLUSION: FLACS significantly reduces EPT compared to CCS. Furthermore, the novel Spiderweb pattern significantly reduces EPT in patients with a cataract of NO3 compared to CCS, but also to FLACS with the existing radial pattern (No-Spiderweb).

MODIFIED SUTURELESS INTRASCLERAL FIXATION TECHNIQUE FOR SECONDARY INTRAOCULAR LENS IMPLANTATION: A Pilot Study.

BACKGROUND/PURPOSE: To demonstrate possible complications of a new intraocular lens for sutureless secondary scleral implantation and modifications of the surgical technique to optimize outcomes. METHODS: A retrospective study of 16 eyes (16 patients) who underwent a secondary intraocular lens implantation using the Carlevale intraocular lens (Soleko, Italy) with two anchor haptics for intrascleral implantation (mean follow-up 2.2 months). RESULTS: The visual acuity did not improve statistically significantly postoperatively ( P = 0.601). Seven (44%) patients suffered from postoperative hypotonia (intraocular pressure <5 mmHg) during the first three postoperative days. CONCLUSION: Owing to the early postoperative hypotony, we decided to modify the surgical technique. We present several suggestions to optimize the technique and outcome such as positioning the sclerotomies at the 2 and 8 o'clock positions, using 27 G trocars alone and suturing the frown incisions using self-resorbing sutures.

Translation of hyaluronic acid-based vitreous substitutes towards current regulations for medical devices.

PURPOSE: Hydrogel-based vitreous substitutes have the potential to overcome the limitations of current clinically used endotamponades. With the goal of entering clinical trials, the present study aimed to (I) transfer the material synthesis of hyaluronic acid-based hydrogels into a routine, pharmaceutical-appropriate production and (II) evaluate the properties of the vitreous substitutes in terms of the current regulations for medical devices (MDR/ISO standards). METHODS: The multistep manufacturing process of the vitreous substitutes, including the modification of hyaluronic acid with glycidyl methacrylate, photocopolymerization with N-vinylpyrrolidone, and successive hydrogel purification, was developed under laboratory conditions, characterized using 1 H-NMR, FT-IR and UV/Vis spectroscopies and HPLC, and transferred towards a pharmaceutical production environment considering GMP standards. The optical and viscoelastic characteristics of the hyaluronic acid-based hydrogels were compared with those of extracted human vitreous and silicone oil. The effect of the hydrogels on the metabolic activity, proliferation and apoptosis of fibroblast (MRC-5, BJ, L929), retinal pigment epithelial (ARPE-19, hiPSC-derived RPE) and photoreceptor cells (661W) was studied as well as their mucosal tolerance via a HET-CAM assay. RESULTS: Hyaluronic acid-based hydrogels having a suitable purity, sterility, high transparency (>90%), appropriate refractive index (1.3365) and viscoelasticity (G' > G″) were prepared in a standardized manner under controlled process conditions. The metabolic activity, proliferation and apoptosis of various cell types as well as egg choroid were unaffected by the hyaluronic acid-based vitreous substitutes, demonstrating their biocompatibility. CONCLUSIONS: The present study demonstrates the successful transferability of the crucial synthesis steps of hyaluronic acid-based hydrogels into a routine, GMP-compliant production process while achieving the optical and viscoelastic properties, biocompatibility and purity required for their clinical use as vitreous substitutes.

Monitoring of wearing and occlusion times with smart shutter glasses-A proof of concept.

PURPOSE: To develop and evaluate an electronic glasses frame for smart liquid crystal shutter glasses that monitors wearing and occlusion times to potentially improve therapy adherence in amblyopia therapy of children. METHODS: The first generation of an electronic glasses frame for adults was further developed, miniaturized and functionally tested in a proof of concept study on a small group of healthy children. Seven healthy children (4 females, 3 males, 2-9 years) were enrolled in the study. The subjects were instructed to wear the smart shutter glasses and to record their activities in daily life. Averaged and individual results were calculated for the precision of wearing position detection and activity recognition. Also, the proper execution of the configured occlusion pattern was observed. RESULTS: The first generation of an electronic glasses frame for smart liquid crystal shutter glasses in a miniaturized form factor for children. A key element is the implementation of the adaptive shutter operation and of smart algorithms for real-time therapy monitoring. In the proof of concept study, these algorithms monitored the state of wearing position, the wearer's activity and the configured occlusion pattern. The average agreement of the detected states of wearing position was 72.6%. The average activity recognition match was 77.3%. The removal of the glasses was 100% correctly detected and the occlusion was 100% halted when active motion was recognized. CONCLUSION: The assembled smart shutter glasses for children are suitable for demonstrating the feasibility of continuous therapy monitoring by calculating wearing and occlusion times due to smart algorithms for wearing position detection, activity recognition, and occlusion monitoring. However, further research and studies are necessary to optimize the individual fit and performance of this wearable therapeutic device.

Asynchronous Teleophthalmology for Monitoring Glaucoma Patients in a Rural German Region: A Retrospective Observational Pilot Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has created an escalating need for limiting in-person examination and potential viral exposure. Under these circumstances, teleophthalmology allows ophthalmologists to continue providing care to patients while ensuring their safety and that of the medical staff. OBJECTIVE: The primary objective of this study was to assess patient satisfaction with an asynchronous teleconsultation for glaucoma patients in a rural German area. Secondary endpoints were patient adherence and the need to change the therapeutic regime. METHODS: This retrospective, observational, and monocentric study included 50 patients diagnosed with primary open-angle glaucoma (n = 49) and ocular hypertension (n = 1) requiring medication to lower intraocular pressure (IOP). Only patients with well-controlled diseases were included, and a brief questionnaire was evaluated, which was completed one year after the baseline visit. Best-corrected visual acuity (BCVA), IOP measurements, visual fields, optical coherence tomography images of the optic nerve head, ultra-widefield photographs of the fundus, and photographs of the anterior segment of the eye were taken at each visit by an experienced optometrist. RESULTS: Of the 50 patients included, the mean number of follow-up visits in this observation period was 4.4. No patient was lost to follow-up, and there were a total of nine missed follow-up visits (but not lost to follow-up). No patients required a change in their treatment regime during the observational period. Regarding patient-focused assessment, the majority of patients were satisfied or very satisfied with teleconsultation in general. CONCLUSION: Asynchronous teleophthalmology is a promising option and effective means to monitor glaucoma patients. The majority of teleophthalmology patients were satisfied with their teleconsultation and adhered to the follow-up schedule. However, prospective trials with a larger number of patients and a more focused examination on specific patient populations are required. Further trials should also focus on the aspect of cost-effectiveness.

Long-Term Biocompatibility of a Highly Viscously Thiol-Modified Cross-Linked Hyaluronate as a Novel Vitreous Body Substitute.

Purpose: In surgical ophthalmology, the treatment of complicated retinal and vitreous diseases is one of the central challenges. For this purpose, the vitreous body is removed as part of the standard therapy and replaced by a temporary tamponade to stabilize the position of the retina. Since the tamponading properties of previous materials such as silicone oils, gases, or semi-fluorinated alkanes are a combination of their surface tension and their buoyancy vector, they cannot completely fill the vitreous cavity. The aim of this work was to test in vivo a novel vitreous body substitute (ViBos strong) based on cross-linked hyaluronic acid for its compatibility. Methods: A pars plana vitrectomy with posterior vitreous detachment was performed in the right eye of 18 pigmented rabbits, with subsequent injection of ViBos strong. Follow-up examination included slit-lamp examination, funduscopy, intraocular pressure measurements (IOP), optical coherence tomography (OCT), and electroretinogram (ERG) measurements. The rabbits were sacrificed at three different time points (1, 3, and 6 months; each 6 animals) and examined macroscopically and prepared for histological examination (HE staining) and immunohistochemistry (Brn3a and glial fibrillary acidic protein (GFAP)). Results: ViBos strong demonstrated good intraoperative handling and remained stable for at least 1 month and degraded slowly over 6 months. IOP was within clinical acceptable values at all follow-up examinations. Retinal function was well preserved after instillation of the hydrogel and comparable to the untreated eye after 6 months in OCT, ERG, and histological examinations. An increase in the GFAP expression was found in the surgery eyes, with a peak in the 3-month group. The Brn3a expression was not significantly affected by vitrectomy with ViBos strong. Conclusion: Highly viscously thiol-modified cross-linked hyaluronate showed a good biocompatibility in rabbit eyes over 6 months after vitrectomy, making it a promising potential as a vitreous substitute.

[Acquired Cataracts]. / Erworbene Katarakte.

Senile or age-related cataract is well known to ophthalmologists and also to colleagues in other medical specialties. Age-related cataract represents the most common cause of blindness worldwide but can be treated very successfully by a standard outpatient surgery. Far less common and therefore less known is the acquired cataract that can present a diagnostic and surgical challenge. The following article provides the reader with an overview of secondary acquired cataracts. The most common subtypes are mentioned first and then discussed in more detail so that the reader should have a structured knowledge after reading this article. This article focuses on acquired cataracts primarily in adults and highlights the surgical features including perioperative characteristics.

Influence of the scleral indentation technique on the re-detachment rate following retinal detachment surgery.

PURPOSE: The aim of this study was to determine whether the choice of scleral indentation technique during primary rhegmatogenous retinal detachment surgery has an influence on the risk of re-detachment. METHODS: We included retrospectively 154 eyes with a primary rhegmatogenous retinal detachment treated in the Eye Clinic Sulzbach/Saar Germany, who were operated on by two experienced surgeons using the same basic surgical setup. Surgeon A performed an external 360° indentation, shaved the vitreous base using the light pipe cap, and used the operating microscope (opm) for direct visualization. Surgeon B performed an external 360° indentation, shaved the vitreous base using a simple indentor, and used an endoillumination (light pipe) with the opm and a handheld widefield lens for direct visualization. RESULTS: Comparing both indentation procedures, 15.66% (13/83) of patients operated on by surgeon A and 9.86% (7/71) of patients operated on by surgeon B had a retinal re-detachment within a follow-up period of 6 months (adj. p = 0.64, two-proportion Z-test). CONCLUSION: The rate of retinal re-detachment could be influenced by the indentation technique at the end of surgery favoring external indentation and internal visualization with an endoilluminator (chandelier light). We attribute this to the better visualization of the vitreous base facilitated by endoillumination. However, many variables play a role in the development of retinal re-detachment, requiring further studies with a larger number of patients.

Systemic Curcumin-Human Serum Albumin in Proliferative Vitreoretinal Retinopathy: A Pilot Study.

Objectives The purpose of this study is to compare the risks of novel postoperative curcumin infusion in patients with increased proliferative vitreoretinal retinopathy (PVR) after retinal detachment with steroid infusion or no treatment. Methods This was a prospective, non-randomized pilot study of 15 eyes of 15 patients (mean age 68 ± 7 years) with retinal detachment, macula off, and flare >15 pc/ms. Postoperatively, the patients received either curcumin-HSA (human serum albumin) infusion (C, n=5), prednisolone infusion (P, n=5), or no therapy (N, n=5) for three days. The outcome measures included postoperative PVR rate, the number of vitreoretinal surgeries (VRS) required, epiretinal membrane development, and visual acuity (VA).  Results All patients had a preoperative VA of hand movements, macula-off detachment situation, and two quadrants rhegmatogenous retinal detachment. Patients underwent VRS at a mean time of 5.6 ± 1.5 (C), 4.9 ± 2.0 (P), 4.7 ± 1.2 (N) days after first recognized symptoms. Postoperative PVR developed just in one eye (P) after 16 days and required VRS due to PVR retinal detachment. The remaining 14 patients of group C and N did not develop PVR. BCVA improved six months post surgery to 0.56 ± 0.31 (P), 0.53 ± 0.19 (D), 0.53 ± 0.17 (N) logMAR. There were no side effects nor complications related to the postoperative infusions.  Conclusions In this pilot study, we demonstrated that a postoperative application of curcumin infusion is a safe option in patients with an increased risk of PVR. Whether or not PVR can be reduced by curcumin infusion would require to be investigated in larger, randomized clinical trials.

Deep Neural Network Driven Speech Classification for Relevance Detection in Automatic Medical Documentation.

The automation of medical documentation is a highly desirable process, especially as it could avert significant temporal and monetary expenses in healthcare. With the help of complex modelling and high computational capability, Automatic Speech Recognition (ASR) and deep learning have made several promising attempts to this end. However, a factor that significantly determines the efficiency of these systems is the volume of speech that is processed in each medical examination. In the course of this study, we found that over half of the speech, recorded during follow-up examinations of patients treated with Intra-Vitreal Injections, was not relevant for medical documentation. In this paper, we evaluate the application of Convolutional and Long Short-Term Memory (LSTM) neural networks for the development of a speech classification module aimed at identifying speech relevant for medical report generation. In this regard, various topology parameters are tested and the effect of the model performance on different speaker attributes is analyzed. The results indicate that Convolutional Neural Networks (CNNs) are more successful than LSTM networks, and achieve a validation accuracy of 92.41%. Furthermore, on evaluation of the robustness of the model to gender, accent and unknown speakers, the neural network generalized satisfactorily.