Inherited Optic Neuropathies: Real-World Experience in the Paediatric Neuro-Ophthalmology Clinic.

Inherited optic neuropathies affect around 1 in 10,000 people in England; in these conditions, vision is lost as retinal ganglion cells lose function or die (usually due to pathological variants in genes concerned with mitochondrial function). Emerging gene therapies for these conditions have emphasised the importance of early and expedient molecular diagnoses, particularly in the paediatric population. Here, we report our real-world clinical experience of such a population, exploring which children presented with the condition, how they were investigated and the time taken for a molecular diagnosis to be reached. A retrospective case-note review of paediatric inherited optic neuropathy patients (0-16 years) in the tertiary neuro-ophthalmology service at Moorfields Eye Hospital between 2016 and 2020 identified 19 patients. Their mean age was 9.3 ± 4.6 (mean ± SD) years at presentation; 68% were male, and 32% were female; and 26% had comorbidities, with diversity of ethnicity. Most patients had undergone genetic testing (95% (n = 18)), of whom 43% (n = 8) received a molecular diagnosis. On average, this took 54.8 ± 19.5 weeks from presentation. A cerebral MRI was performed in 70% (n = 14) and blood testing in 75% (n = 15) of patients as part of their workup. Continual improvement in the investigative pathways for inherited optic neuropathies will be paramount as novel therapeutics become available.

Therapeutic strategies for glaucoma and optic neuropathies.

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.

[Optic neuropathies as an interdisciplinary subject of research]. / Opticheskie neiropatii kak predmet mezhdistsiplinarnogo izucheniya.

Despite the wide range of clinical, instrumental and laboratory methods used in modern ophthalmology, the problem of diagnosing optic neuropathy and identifying its etiology remains relevant. A complex multidisciplinary approach involving various specialists is required in the differential diagnosis of immune-mediated optic neuritis, for example in multiple sclerosis, neuromyelitis optica spectrum disorder, and MOG-associated diseases. Of special interest is differential diagnosis of optic neuropathy in demyelinating diseases of the central nervous system, hereditary optic neuropathies and ischemic optic neuropathy. The article presents a summary of scientific and practical results of differential diagnosis of optic neuropathies with various etiologies. Timely diagnosis and early therapy start reduces the degree of disability in patients with optic neuropathies of different etiologies.

Pembrolizumab-induced optic neuropathy - a case report.

Background: Immune checkpoint inhibitor (ICI) treatment has become important for treating various cancer types, including Hodgkin's lymphoma. However, ICI can overstimulate the immune system, leading to a broad range of immunological side effects, known as immune-related adverse events (irAEs). Here, we report a case of optic neuropathy caused by pembrolizumab. Case presentation: A patient with Hodgkin's lymphoma received pembrolizumab every three weeks. Twelve days after the sixth cycle of pembrolizumab, the patient was admitted to the emergency department with blurred vision, visual field impairment and altered color perception affecting the right eye. The diagnosis of immune-related optic neuropathy was established. Pembrolizumab was stopped permanently and high-dose steroid treatment was immediately started. This emergency treatment led to a satisfactory binocular vision and an improvement of visual acuity testing results. After another 7 months, the left eye was affected with the same symptoms. At this time, only an extended immunosuppressive therapy consisting of high-dose steroid treatment, plasmapheresis, immunoglobulin treatment, retrobulbar injection of steroids and mycophenolate mofetil, successfully reduced the symptoms. Conclusions: This case highlights the need for prompt recognition and treatment of rare irAEs, such as optic neuropathy. Urgent treatment with initial high-dose steroid treatment is required to avoid persistent loss of visual acuity. Options for further treatment are mainly based on small case series and case reports. In our case, a retrobulbar injection of steroids in combination with mycophenolate mofetil showed significant success in treating steroid-refractory optic neuropathy.

Deep learning: applications in retinal and optic nerve diseases.

Deep learning (DL) represents a paradigm-shifting, burgeoning field of research with emerging clinical applications in optometry. Unlike traditional programming, which relies on human-set specific rules, DL works by exposing the algorithm to a large amount of annotated data and allowing the software to develop its own set of rules (i.e. learn) by adjusting the parameters inside the model (network) during a training process in order to complete the task on its own. One major limitation of traditional programming is that, with complex tasks, it may require an extensive set of rules to accurately complete the assignment. Additionally, traditional programming can be susceptible to human bias from programmer experience. With the dramatic increase in the amount and the complexity of clinical data, DL has been utilised to automate data analysis and thus to assist clinicians in patient management. This review will present the latest advances in DL, for managing posterior eye diseases as well as DL-based solutions for patients with vision loss.

Understanding the molecular basis and pathogenesis of hereditary optic neuropathies: towards improved diagnosis and management.

Hereditary optic neuropathies result from defects in the human genome, both nuclear and mitochondrial. The two main and most recognised phenotypes are dominant optic atrophy and Leber hereditary optic neuropathy. Advances in modern molecular diagnosis have expanded our knowledge of genotypes and phenotypes of inherited disorders that affect the optic nerve, either alone or in combination, with various forms of neurological and systemic degeneration. A unifying feature in the pathophysiology of these disorders appears to involve mitochondrial dysfunction, suggesting that the retinal ganglion cells and their axons are especially susceptible to perturbations in mitochondrial homoeostasis. As we better understand the pathogenesis behind these genetic diseases, aetiologically targeted therapies are emerging and entering into clinical trials, including treatments aimed at halting the cascade of neurodegeneration, replacing or editing the defective genes or their protein products, and potentially regenerating damaged optic nerves, as well as preventing generational disease transmission.

Global brain network modularity dynamics after local optic nerve damage following noninvasive brain stimulation: an EEG-tracking study.

Tightly connected clusters of nodes, called communities, interact in a time-dependent manner in brain functional connectivity networks (FCN) to support complex cognitive functions. However, little is known if and how different nodes synchronize their neural interactions to form functional communities ("modules") during visual processing and if and how this modularity changes postlesion (progression or recovery) following neuromodulation. Using the damaged optic nerve as a paradigm, we now studied brain FCN modularity dynamics to better understand module interactions and dynamic reconfigurations before and after neuromodulation with noninvasive repetitive transorbital alternating current stimulation (rtACS). We found that in both patients and controls, local intermodule interactions correlated with visual performance. However, patients' recovery of vision after treatment with rtACS was associated with improved interaction strength of pathways linked to the attention module, and it improved global modularity and increased the stability of FCN. Our results show that temporal coordination of multiple cortical modules and intermodule interaction are functionally relevant for visual processing. This modularity can be neuromodulated with tACS, which induces a more optimal balanced and stable multilayer modular structure for visual processing by enhancing the interaction of neural pathways with the attention network module.

Interprofessional Electronic Consultations for the Diagnosis and Management of Neuro-Ophthalmic Conditions.

BACKGROUND: Interprofessional electronic consultation (eConsult) is a telemedicine modality in which consulting providers review outside records and provide recommendations without in-person consultation. The purpose of this study was to describe the utilization of eConsults in the management of neuro-ophthalmic conditions. METHODS: Retrospective cohort study of all patients who received an eConsult for a neuro-ophthalmic condition at a single quaternary referral center from 2018 to 2020. Main outcome measures included proportion of eConsults in which sufficient data were provided to the neuro-ophthalmologist to generate a definitive management decision, proportion of patients for whom an in-person neuro-ophthalmology evaluation was recommended, and the eConsult's impact on patient care. RESULTS: Eighty eConsults were conducted on 78 patients during the 3-year study period. Forty-eight (60.0%) subjects were female, mean age was 54 years, and 65 (81.3%) were White. The median time from eConsult request to completion was 4 days (range: 0-34 days). The most frequent eConsult questions were vision/visual field disturbances in 28 (35.0%) cases, optic neuropathies in 22 (27.5%), and optic disc edema in 17 (21.3%). At the time of eConsult, sufficient prior information was provided in 35 (43.8%) cases for the neuro-ophthalmologist to provide a definitive management decision. In 45 (56.3%) eConsults, further diagnostic testing was recommended. In-person neuro-ophthalmology consultation was recommended in 24 (30.0%) cases. Sixty-one (76.3%) eConsults provided diagnostic and/or treatment direction, and 12 (15.0%) provided reassurance. CONCLUSION: eConsults increase access to timely neuro-ophthalmic care and provide diagnostic and treatment direction to non-neuro-ophthalmology providers when sufficient information is provided at the time of eConsult.

Dysthyroid optic neuropathy: Demographics, risk factors, investigations, and management outcomes.

Purpose: To analyze the clinical presentations, risk factors, and management outcomes in patients presenting with dysthyroid optic neuropathy (DON). Methods: This is a retrospective, single-center study carried out on consecutive patients presenting with DON over a period of 4 years (2013-2016). The VISA classification was used at the first visit and subsequent follow-ups. The diagnosis was based on optic nerve function tests and imaging features. Demographic profiles, clinical features, risk factors, and management outcomes were analyzed. Results: Thirty-seven eyes of 26 patients diagnosed with DON were included in the study. A significant male preponderance was noted (20, 76.92%). Twenty patients (76.9%, P = 0.011) had hyperthyroidism, and 15 (57.69%, P = 0.02) were smokers. Decreased visual acuity was noted in 28 eyes (75.6%). Abnormal color vision and relative afferent pupillary defects were seen in 24 (64.86%) eyes, and visual field defects were seen in 30 (81.01%) eyes. The visual evoked potential (VEP) showed a reduced amplitude in 30 (96.77%, P = 0.001) of 31 eyes and delayed latency in 20 (64.51%, P = 0.0289) eyes. Twenty-six (70.27%) patients were treated with intravenous methyl prednisolone (IVMP) alone, whereas 11 (29.72%) needed surgical decompression. The overall best-corrected visual acuity improved by 0.2 l logMARunits. There was no statistically significant difference in outcome between medically and surgically treated groups. Four patients developed recurrent DON, and all of them were diabetics. Conclusion: Male gender, hyperthyroid state, and smoking are risk factors for developing DON. VEP, apical crowding, and optic nerve compression are sensitive indicators for diagnosing DON. Diabetics may have a more defiant course and are prone to develop recurrent DON.

Approach to the diagnosis and management of nutritional optic neuropathies.

PURPOSE OF REVIEW: Nutritional deficiency is an under-recognized cause of optic neuropathy. The purpose of this review is to discuss how to identify, diagnose, and appropriately manage patients with nutritional optic neuropathy. RECENT FINDINGS: Nutritional deficiencies have long been thought to be more prevalent in the developing countries. However, with the advent of bariatric surgery, restrictive/selective diets, and the increase in alcohol dependence, it is not uncommon to see nutritional optic neuropathies in the developed world. SUMMARY: Although nutritional optic neuropathy can cause severe and debilitating vision loss, it is often reversible when it is diagnosed and treated in a timely manner.

Optic Disc Drusen in Patients With Ocular Hypertension: A Case Series and Review of the Literature.

BACKGROUND: The identification of glaucomatous optic neuropathy in the setting of optic disc drusen (ODD) is a challenge, and the decision of whether to offer treatment in the form of intraocular pressure (IOP) reduction is controversial. Here, we present a series of patients with coexisting ocular hypertension and ODD to evaluate clinical features, treatment options, and progression of optic neuropathy. In addition, a review of the literature on ODD with elevated IOP is provided. METHODS: Six patients with ODD and a history of ocular hypertension are presented. Components of the examination and imaging modalities used to establish the diagnosis of ODD were recorded and a description of ocular hypertension history, glaucoma testing, and the potential treatment of IOP were also provided. RESULTS: In this series, 4 of 6 patients with concurrent ocular hypertension and ODD showed progression of optic neuropathy as assessed by visual field or retinal nerve fiber layer thickness. Of the 2 patients who did not show evidence of progression, 1 was treated with IOP-lowering medications and 1 was observed off treatment. Of the 4 patients who showed evidence of progression, all 4 were initially treated with IOP-lowering medications and 2 ultimately went on to have trabeculectomy surgery. In the patients with progressive optic neuropathy, lowering the IOP seemed to halt the progression suggesting there was a pressure-sensitive component. CONCLUSIONS: Distinguishing changes to the optic nerve, particularly the structural changes at the lamina cribrosa of true glaucomatous optic neuropathy in the setting of ODD, is a challenge. Careful consideration of risk factors including age, presenting features, progression indicators, and management goals is to be accounted for in the decision to offer treatment. We see the presence ODD in the patients with ocular hypertension as an additional risk for progressive changes to the nerve fiber layer and visual field that needs to be considered when determining whether to initiate therapy. Our data suggest that treatment of IOP in the patients with ocular hypertension with ODD and evidence of progression reduces the risk of further progression. Further work is needed to determine whether progression of optic neuropathy in the setting of coexisting ODD and ocular hypertension is related mechanistically to predominantly an ODD-type process, a glaucomatous process, or a combination thereof.

Neuro-ophthalmic manifestations of cancer: a narrative review.

BACKGROUND AND OBJECTIVE: Neuro-ophthalmic manifestations of cancer are vast and early recognition of a serious ocular condition due to either cancer or its therapy is important for both vision preservation as well as providing valuable treatment and prognostic information regarding the underlying malignancy. This review focuses on direct and indirect effects of cancer on the eye and its adnexa, hematologic malignancy, complications of traditional and novel oncologic therapies, and paraneoplastic syndromes as they relate to the eye as these disorders can lead to potentially devastating or irreversible vision loss. METHODS: PubMed was searched primarily for the following topics: optic nerve infiltration, primary vitreoretinal lymphoma (PVRL), ocular paraneoplastic disorders, and ophthalmic complications of cancer therapeutics. Literature was selected based on historical significance and landmark studies (e.g., Cross et al. series of paraneoplastic optic neuritis patients; Chan's textbook on primary intraocular lymphoma) as well as publications published after 2000. References from select studies were additionally included. Given the sparsity of literature on many subjects, most publications were included during this time frame in our review. KEY CONTENT AND FINDINGS: There are several ophthalmic entities that the oncologist should be aware of including leukemic optic nerve infiltration, PVRL, paraneoplastic syndromes as they related to the eye, and adverse effects of therapeutics. Unfortunately, given the rarity of some of these entities [e.g., paraneoplastic optic neuropathy (PON), cancer-associated retinopathy (CAR)], diagnosis can be difficult and treatment options are often limited. CONCLUSIONS: Oncologists can develop a set of basic ophthalmology examination skills that will help to triage and manage patient eye complaints. In certain instances, oncologists have the potential to avert devastating vision loss with early recognition of neuro-ophthalmic complications.

Disease course of Chronic Relapsing Inflammatory Optic Neuropathy (CRION) in a single care center.

BACKGROUND: Chronic relapsing inflammatory optic neuropathy (CRION) is a recurrent, idiopathic optic neuritis and is considered as a rare disease. OBJECTIVE: To describe the clinical course during long-term follow-up of patients with a diagnosis of CRION. METHODS: From a cohort of 1,735 patients with demyelinating disorders, we selected patients aged over 16 years with CRION according to current criteria. Demographic and clinical data, including initial presentation, symptoms, number of relapses, time delay in diagnosis, diagnostic methods, and treatment were obtained from clinical files. Infections, autoimmune diseases, and multiple sclerosis, among other conditions, were ruled out in all patients. RESULTS: We analyzed 30 patients with CRION: 24 women and six men, with mean age of 42.8±10.2 years, median disease course of 7.9 years (5.29-13.1), and median number of attacks of 2 (IQR 2-4). The initial manifestation was ocular pain in 97% and bilateral and sequential affection in 87%. Visual acuity was recovered in 50%, did not improve in 33%, and recovered incompletely in 17%. Antibodies against aquaporin-4 (AQP4-Abs) were negative in 73.3%. Magnetic resonance imaging of the brain was normal in 76.7%. None of the patients evolved to another demyelinating disease over time. Initial treatment was methylprednisolone in 100%, and plasmapheresis in 20%. Currently, all patients are on maintenance treatment with mycophenolate mofetil or rituximab with a decrease in relapsing rate. CONCLUSIONS: Diagnosis of CRION is challenging and should be kept in mind. Prompt diagnosis, adequate treatment and close follow-up are essential to prevent disabling sequelae in these patients.

The safety and efficacy of gene therapy treatment for monogenic retinal and optic nerve diseases: A systematic review.

PURPOSE: This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases. METHODS: This review was prospectively registered (CRD42021229812). A comprehensive literature search was performed in Ovid MEDLINE, Ovid Embase, Cochrane Central, and clinical trial registries (February 2021). Clinical studies describing DNA-based gene therapy treatments for monogenic posterior ocular diseases were eligible for inclusion. Risk of bias evaluation was performed. Data synthesis was undertaken applying Synthesis Without Meta-analysis guidelines. RESULTS: This study identified 47 full-text publications, 50 conference abstracts, and 54 clinical trial registry entries describing DNA-based ocular gene therapy treatments for 16 different genetic variants. Study summaries and visual representations of safety and efficacy outcomes are presented for 20 unique full-text publications in RPE65-mediated retinal dystrophies, choroideremia, Leber hereditary optic neuropathy, rod-cone dystrophy, achromatopsia, and X-linked retinoschisis. The most common adverse events were related to lid/ocular surface/cornea abnormalities in subretinal gene therapy trials and anterior uveitis in intravitreal gene therapy trials. CONCLUSION: There is a high degree of variability in ocular monogenic gene therapy trials with respect to study design, statistical methodology, and reporting of safety and efficacy outcomes. This review improves the accessibility and transparency in interpreting gene therapy trials to date.

Induced Pluripotent Stem Cells for Inherited Optic Neuropathies-Disease Modeling and Therapeutic Development.

BACKGROUND: Inherited optic neuropathies (IONs) cause progressive irreversible visual loss in children and young adults. There are limited disease-modifying treatments, and most patients progress to become severely visually impaired, fulfilling the legal criteria for blind registration. The seminal discovery of the technique for reprogramming somatic nondividing cells into induced pluripotent stem cells (iPSCs) has opened several exciting opportunities in the field of ION research and treatment. EVIDENCE ACQUISITION: A systematic review of the literature was conducted with PubMed using the following search terms: autosomal dominant optic atrophy, ADOA, dominant optic atrophy, DOA, Leber hereditary optic neuropathy, LHON, optic atrophy, induced pluripotent stem cell, iPSC, iPSC derived, iPS, stem cell, retinal ganglion cell, and RGC. Clinical trials were identified on the ClinicalTrials.gov website. RESULTS: This review article is focused on disease modeling and the therapeutic strategies being explored with iPSC technologies for the 2 most common IONs, namely, dominant optic atrophy and Leber hereditary optic neuropathy. The rationale and translational advances for cell-based and gene-based therapies are explored, as well as opportunities for neuroprotection and drug screening. CONCLUSIONS: iPSCs offer an elegant, patient-focused solution to the investigation of the genetic defects and disease mechanisms underpinning IONs. Furthermore, this group of disorders is uniquely amenable to both the disease modeling capability and the therapeutic potential that iPSCs offer. This fast-moving area will remain at the forefront of both basic and translational ION research in the coming years, with the potential to accelerate the development of effective therapies for patients affected with these blinding diseases.

Human Pluripotent Stem Cell-Derived Neural Progenitor Cells Promote Retinal Ganglion Cell Survival and Axon Recovery in an Optic Nerve Compression Animal Model.

Human pluripotent stem cell-derived neural progenitor cells (NPCs) have the potential to recover from nerve injury. We previously reported that human placenta-derived mesenchymal stem cells (PSCs) have neuroprotective effects. To evaluate the potential benefit of NPCs, we compared them to PSCs using R28 cells under hypoxic conditions and a rat model of optic nerve injury. NPCs and PSCs (2 × 106 cells) were injected into the subtenon space. After 1, 2, and 4 weeks, we examined changes in target proteins in the retina and optic nerve. NPCs significantly induced vascular endothelial growth factor (Vegf) compared to age-matched shams and PSC groups at 2 weeks; they also induced neurofilaments in the retina compared to the sham group at 4 weeks. In addition, the expression of brain-derived neurotrophic factor (Bdnf) was high in the retina in the NPC group at 2 weeks, while expression in the optic nerve was high in both the NPC and PSC groups. The low expression of ionized calcium-binding adapter molecule 1 (Iba1) in the retina had recovered at 2 weeks after NPC injection and at 4 weeks after PSC injection. The expression of the inflammatory protein NLR family, pyrin domain containing 3 (Nlrp3) was significantly reduced at 1 week, and that of tumor necrosis factor-α (Tnf-α) in the optic nerves of the NPC group was lower at 2 weeks. Regarding retinal ganglion cells, the expressions of Brn3a and Tuj1 in the retina were enhanced in the NPC group compared to sham controls at 4 weeks. NPC injections increased Gap43 expression from 2 weeks and reduced Iba1 expression in the optic nerves during the recovery period. In addition, R28 cells exposed to hypoxic conditions showed increased cell survival when cocultured with NPCs compared to PSCs. Both Wnt/ß-catenin signaling and increased Nf-ĸb could contribute to the rescue of damaged retinal ganglion cells via upregulation of neuroprotective factors, microglial engagement, and anti-inflammatory regulation by NPCs. This study suggests that NPCs could be useful for the cellular treatment of various optic neuropathies, together with cell therapy using mesenchymal stem cells.