The Impact of Leber Hereditary Optic Neuropathy on the Quality of Life of Patients and Their Relatives: A Qualitative Study

Leber hereditary optic neuropathy: utilities and carer burden from British and Irish participants

BACKGROUND

Leber hereditary optic neuropathy (LHON) is a rare, maternally inherited, mitochondrial disease resulting in sudden, progressive central vision loss. The condition affects numerous aspects of daily life, functioning and overall health-related quality of life (HRQL), which may spillover to carers.

METHODS

Two studies were designed to estimate patient utilities associated with varying visual acuity in LHON (study 1) and to explore carer burden (study 2). In study 1, eight LHON health state vignettes (mild vision loss [LogMAR < 0.3] through to light perception [LogMAR ≥ 4]) were valued by the UK and Republic of Ireland (ROI) general pubic using the Health Utilities Index- 3 (HUI-3) and EQ-5D in an online survey (N = 360) and in time trade-off interviews (TTO; n = 120). In study 2, nine carers completed in-depth interviews exploring carer burden, the Care-related Quality of Life instrument (CarerQol), EQ-5D-5L and the Work Productivity and Activity Impairment Questionnaire (WPAI).

RESULTS

Study 1 demonstrated lower utilities for people with worse visual function. Mild vision loss (LogMAR < 0.3) was rated as 0.84 (HUI-3), 0.79 (EQ-5D) and 0.88 (TTO). Light perception (LogMAR ≥ 4), the most severe health state, was rated as 0.18 (HUI-3), 0.34 (EQ-5D), and 0.36 (TTO). In study 2, qualitative findings revealed substantial burden for many carers and family members. The most prominent impacts were emotional (e.g., guilt, devastation), especially related to the maternal inheritance of LHON. Impacts to carers' daily life, social life and relationships, work, and finances were also described. Standardised measures identified little impact on HRQL (EQ-5D-5L = 0.89), but some carer related burden (CarerQol-7D = 78.4). The WPAI revealed an overall work impairment of 15% and activity impairment of 37%.

CONCLUSIONS

Findings suggest the HUI-3 may be more sensitive to the HRQL impact of vision loss compared to the EQ-5D and TTO method. The data indicate the potential value of an effective treatment for LHON. Qualitative findings describe the impact of LHON on carers. However, the burden described in the qualitative data was incongruent with quantitative measures, particularly the EQ-5D-5L. This demonstrates the value of conducting mixed-methods research and the importance of selecting measures which capture population-relevant concepts.

Leber Hereditary Optic Neuropathy: Support, Genetic Prediction and Accurate Genetic Counselling Enhance Family Planning Choices

With the increased availability of genetic testing and the addition of mitochondrial genetic variants on disease panels, accurate genetic counselling for individuals and families affected by, or at risk of, Leber hereditary optic neuropathy (LHON) is becoming increasingly relevant. Challenges in providing genetic counselling for LHON include its mitochondrial inheritance pattern, different haplogroups, incomplete penetrance and that it predominantly affects males. Accurate genetic counselling aims to avoid incorrect disease-risk assessment and delays in either diagnosis or implementation of psychosocial support. Families are also empowered to make autonomous health decisions regarding potential trigger factors for LHON vision loss and informed reproductive choices. Using clinical vignettes, this review demonstrates that an increased awareness of LHON amongst eye care, general and genetic health professionals can address challenges and misconceptions.

Meta-analysis of treatment outcomes for patients with m.11778G>A MT-ND4 Leber hereditary optic neuropathy

Our aim was to assess the visual outcomes of patients with Leber hereditary optic neuropathy (LHON) harboring the m.11778G>A MT-ND4 mutation who had no treatment (natural history) or received idebenone or lenadogene nolparvovec. Efficacy outcomes included clinically relevant recovery (CRR) from nadir and final best-corrected visual acuity (BCVA). For the natural history and idebenone groups, we performed a systematic review of the literature and available clinical/regulatory reports. For the lenadogene nolparvovec group, all data from phase 3 studies were included. The overall effect and its 95 % confidence interval (CI) were estimated using a random effects model. For each meta-analysis, patients had a mean age of approximately 30 years at vision loss and were mostly (≥78 %) men. The CRR from nadir [95 % CI] at eye level was 17 % [7 %; 30 %] (n=316 eyes), 31 % [24 %; 40 %] (n=313) and 59 % [54 %; 64 %] (n=348) in untreated, idebenone-treated and lenadogene nolparvovec-treated patients, respectively. This gradient of efficacy was also observed with CRR at the patient level and final BCVA. There was a gradient of efficacy in all assessed visual outcomes, more marked for CRR than for final BCVA, with lenadogene nolparvovec gene therapy superior to idebenone treatment, and both superior to the natural history of the disease.

Five-Year Outcomes of Lenadogene Nolparvovec Gene Therapy in Leber Hereditary Optic Neuropathy

Importance

Limited studies have assessed the long-term benefit/risk of gene therapy for Leber hereditary optic neuropathy (LHON).

Objective

To determine the safety and efficacy of lenadogene nolparvovec in patients with LHON due to the MT-ND4 gene variant for up to 5 years after administration.

Design, Setting, and Participants

The RESCUE and REVERSE Long-Term Follow-up Study (RESTORE), conducted from 2018 to 2022, is the 5-year follow-up study of the 2 phase 3 clinical studies RESCUE (Efficacy Study of Lenadogene Nolparvovec for the Treatment of Vision Loss Up to 6 Months From Onset in LHON Due to the MT-ND4 Mutation) and REVERSE (Efficacy Study of Lenadogene Nolparvovec for the Treatment of Vision Loss From 7 Months to 1 Year From Onset in LHON Due to the MT-ND4 Mutation). At the end of each study, ie, 2 years after gene therapy administration, patients were offered enrollment in the RESTORE trial, a multinational, multicenter, prospective study, for an additional 3 years of follow-up. Patients with LHON due to the MT-ND4 gene variant received lenadogene nolparvovec in 1 eye and a sham injection in the other eye.

Intervention

Lenadogene nolparvovec was administered as a single intravitreal injection in the RESCUE/REVERSE studies.

Main Outcomes and Measures

Measures included best-corrected visual acuity (BCVA), quality of life using the National Eye Institute visual functioning questionnaire 25 (NEI VFQ-25), and adverse events.

Results

Among the 76 patients who received gene therapy in the RESCUE (n = 39) and REVERSE (n = 37) studies, 72 (94.7%) completed these studies; 62 patients (81.6%) participated in the RESTORE trial, and 55 patients (72.4%) completed the 5-year follow-up. Participants were mostly male (49 [79.0%]) with a mean (SD) age of 35.9 (15.3) years at treatment. At baseline, the mean (SD) BCVA was 1.5 (0.5) logMAR (20/600 Snellen) in eyes to be treated with lenadogene nolparvovec and 1.4 (0.5) logMAR (20/500) in sham eyes. At the end of the RESCUE/REVERSE trials, ie, 2 years after treatment, eyes treated with lenadogene nolparvovec and eyes treated with sham reached a mean BCVA value of 1.4 (0.6) logMAR (20/500). The mean (SD) change from baseline to year 2 was -0.05 (0.6) logMAR (+1 line) and 0.01 (0.6) logMAR (-0 line) in gene therapy-treated and sham eyes, respectively (difference, -0.03; 95% CI, -0.16 to 0.09; P = .60). Five years after treatment, the bilateral improvement from nadir was similar to that observed at 2 years, with a mean (SD) change in BCVA of -0.4 (0.5) logMAR (more than +4 lines) for eyes treated with lenadogene nolparvovec and -0.4 (0.4) logMAR (+4 lines) for eyes treated with sham (difference, -0.05; 95% CI, -0.15 to 0.04; P = .27). An improvement of at least -0.3 logMAR (+3 lines) from the nadir in at least 1 eye was observed in 66.1% of participants (41 of 62). Between 2 and 5 years, intraocular inflammation was noted in 4 participants with 8 events in eyes treated with lenadogene nolparvovec and 1 event in an eye treated with sham.

Conclusions and Relevance

In this analysis of the RESTORE trial, follow-up of patients with LHON due to the MT-ND4 gene variant unilaterally treated with lenadogene nolparvovec demonstrated a sustained bilateral improvement in BCVA and a good safety profile up to 5 years after treatment. This evidence of persistent benefit over time is promising for the use of gene therapy in these patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT03406104.

Clinical trials in Leber hereditary optic neuropathy: outcomes and opportunities

PURPOSE OF REVIEW

Leber hereditary optic neuropathy (LHON) is a mitochondrial DNA disease characterised by sequential bilateral vision loss due to loss of retinal ganglion cells. The purpose of this review is to provide an update on the results of recent clinical trials for LHON, focusing on studies of idebenone and lenadogene nolparvovec gene therapy.

RECENT FINDINGS

Evidence from three clinical studies (RHODOS, RHODOS-OFU, and LEROS) suggest that idebenone should be started early and continued for at least 24 months. Treatment effect varies according to the stage of LHON and the underlying mutation. Favourable outcomes are associated with the m.11778G>A mutation and chronic eyes with the m.14484T>C mutation. Caution should be taken in subacute/dynamic eyes with the m.3460G>A mutation, due to possible clinical worsening with idebenone. Compared to eyes from an external natural history cohort, pooled data from four clinical studies (RESCUE, REVERSE, RESTORE and REFLECT) show that a single intravitreal injection of lenadogene nolparvovec can result in sustained bilateral visual improvement in m.11778G>A LHON patients aged ≥15 years when treated within 1 year of onset. Although the treatment effect is modest, the final visual acuity of treated patients (∼1.2 logMAR) significantly differs from the published natural history of LHON and the treatment benefit is more pronounced than the effect of idebenone alone in patients with the m.11778G>A mutation.

SUMMARY

There is increasing evidence for the potential therapeutic benefit of idebenone and lenadogene nolparvovec gene therapy.

Leber hereditary optic neuropathy in Czechia and Slovakia: Quality of life and costs from patient perspective

Introduction

Leber hereditary optic neuropathy (LHON) is the most frequent mitochondrial disease causing dyschromatopsia and progressive central visual loss that is subacute in progression and painless. Several studies have been published assessing QoL in patients with LHON, but no estimate of the economic burden has been reported to date. This study aims to quantify direct non-medical and indirect costs (productivity loss) incurred by LHON patients and their informal caregivers in Czechia and Slovakia, as well as to assess their quality of life.

Methods

The study was performed in 27 adults and children with LHON. To determine the socioeconomic burden of LHON, separate questionnaires for adults, children, and their parents were developed, including demographic and socioeconomic data. The following data were collected: age, education, family size, severity of LHON, non-medical direct and indirect costs of LHON.

Results

The mean age of adult respondents was 36.1 years (SD 13.1; n = 21). The total cost of absenteeism was EUR 1003 per person/year in adult employees, and EUR 2711 per person/year in children's parents. The productivity loss as a consequence of LHON due to combined relative absenteeism and relative presenteeism was estimated at EUR 9840 per an adult patient/year, and EUR 6298 per a parent/year, respectively. The mean cost of informal care was estimated at EUR 4502 (SD 4772; n = 6) per person/year. The mean VFQ-25 score for adult patients with LHON was 43.47 (SD 15.86).

Conclusion

The results of this study clearly show that patients with LHON and their families face an extensive socioeconomic burden related to this rare disease. Early, timely and appropriate access to diagnosis, treatment, and reimbursement decisions, but also to psychological counselling and services may help the patients and their relatives adapt and cope with the challenging aspects of vision loss and life with the disease.

Social Media in Neuro-Ophthalmology: Paradigms, Opportunities, and Strategies

BACKGROUND

Social media (SoMe) is an integral part of life in the 21st century. Its potential for rapid dissemination and amplification of information offers opportunities for neuro-ophthalmologists to have an outsized voice to share expert-level knowledge with the public, other medical professionals, policymakers, and trainees. However, there are also potential pitfalls, because SoMe may spread incorrect or misleading information. Understanding and using SoMe enables neuro-ophthalmologists to influence and educate that would otherwise be limited by workforce shortages.

EVIDENCE ACQUISITION

A PubMed search for the terms "social media" AND "neuro-ophthalmology," "social media" AND "ophthalmology," and "social media" AND "neurology" was performed.

RESULTS

Seventy-two neurology articles, 70 ophthalmology articles, and 3 neuro-ophthalmology articles were analyzed. A large proportion of the articles were published in the last 3 years (2020, 2021, 2022). Most articles were analyses of SoMe content; other domains included engagement analysis such as Altmetric analysis, utilization survey, advisory opinion/commentary, literature review, and other. SoMe has been used in medicine to share and recruit for scientific research, medical education, advocacy, mentorship and medical professional networking, and branding, marketing, practice building, and influencing. The American Academy of Neurology, American Academy of Ophthalmology, and North American Neuro-Ophthalmology Society have developed guidelines on the use of SoMe.

CONCLUSIONS

Neuro-ophthalmologists may benefit greatly from harnessing SoMe for the purposes of academics, advocacy, networking, and marketing. Regularly creating appropriate professional SoMe content can enable the neuro-ophthalmologist to make a global impact.

Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases?

Optic nerve disorders encompass a wide spectrum of conditions characterized by the loss of retinal ganglion cells (RGCs) and subsequent degeneration of the optic nerve. The etiology of these disorders can vary significantly, but emerging research highlights the crucial role of oxidative stress, an imbalance in the redox status characterized by an excess of reactive oxygen species (ROS), in driving cell death through apoptosis, autophagy, and inflammation. This review provides an overview of ROS-related processes underlying four extensively studied optic nerve diseases: glaucoma, Leber's hereditary optic neuropathy (LHON), anterior ischemic optic neuropathy (AION), and optic neuritis (ON). Furthermore, we present preclinical findings on antioxidants, with the objective of evaluating the potential therapeutic benefits of targeting oxidative stress in the treatment of optic neuropathies.

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.

Indirect Comparison of Lenadogene Nolparvovec Gene Therapy Versus Natural History in Patients with Leber Hereditary Optic Neuropathy Carrying the m.11778G>A MT-ND4 Mutation

INTRODUCTION

Lenadogene nolparvovec is a promising novel gene therapy for patients with Leber hereditary optic neuropathy (LHON) carrying the m.11778G>A ND4 mutation (MT-ND4). A previous pooled analysis of phase 3 studies showed an improvement in visual acuity of patients injected with lenadogene nolparvovec compared to natural history. Here, we report updated results by incorporating data from the latest phase 3 trial REFLECT in the pool, increasing the number of treated patients from 76 to 174.

METHODS

The visual acuity of 174 MT-ND4-carrying patients with LHON injected in one or both eyes with lenadogene nolparvovec from four pooled phase 3 studies (REVERSE, RESCUE and their long-term extension trial RESTORE; and REFLECT trial) was compared to the spontaneous evolution of an external control group of 208 matched patients from 11 natural history studies.

RESULTS

Treated patients showed a clinically relevant and sustained improvement in their visual acuity when compared to natural history. Mean improvement versus natural history was - 0.30 logMAR (+ 15 ETDRS letters equivalent) at last observation (P < 0.01) with a maximal follow-up of 3.9 years after injection. Most treated eyes were on-chart as compared to less than half of natural history eyes at 48 months after vision loss (89.6% versus 48.1%; P < 0.01) and at last observation (76.1% versus 44.4%; P < 0.01). When we adjusted for covariates of interest (gender, age of onset, ethnicity, and duration of follow-up), the estimated mean gain was - 0.43 logMAR (+ 21.5 ETDRS letters equivalent) versus natural history at last observation (P < 0.0001). Treatment effect was consistent across all phase 3 clinical trials. Analyses from REFLECT suggest a larger treatment effect in patients receiving bilateral injection compared to unilateral injection.

CONCLUSION

The efficacy of lenadogene nolparvovec in improving visual acuity in MT-ND4 LHON was confirmed in a large cohort of patients, compared to the spontaneous natural history decline. Bilateral injection of gene therapy may offer added benefits over unilateral injection.

TRIAL REGISTRATION NUMBERS

NCT02652780 (REVERSE); NCT02652767 (RESCUE); NCT03406104 (RESTORE); NCT03293524 (REFLECT); NCT03295071 (REALITY).

Psychometric Validity of the Visual Function Index in Leber Hereditary Optic Neuropathy

Purpose

The purpose of this study was to determine the psychometric validity of the Visual Function Index (VF-14) for use by patients with Leber hereditary optic neuropathy (LHON).

Methods

Rasch analysis was conducted in two stages using data for 196 individuals (74.5% male) carrying one of the three primary LHON mutations and affected by vision loss. In stage 1, scale unidimensionality, scale-to-sample targeting, response category threshold ordering, item fit statistics, local dependency, and reliability were assessed. In stage 2, iterative post-hoc revisions of the VF-14 structure (VF-14R) were applied and psychometrically re-evaluated.

Results

Issues identified with the VF-14 included disordered response thresholds (12/14 items), local dependency (10/91 pairwise dependencies), and evidence of multidimensionality. However, the distribution of person estimates and item thresholds were fairly well matched, only one item showed misfit to the Rasch model, and there was good reliability (Person Separation Index 0.84). Rasch-informed VF-14 revisions included removing both driving items and the misfitting sports item, rescoring response options across all items by merging two response categories, and accounting for the dependency between two reading items. The VF-14R demonstrated improved psychometric validity.

Conclusions

Clinicians and researchers using the VF-14 with LHON patients should be aware of its limitations. Compared to the original version, the proposed Rasch-based structure of the VF-14R appears to offer improved psychometric performance and interpretation of vision-related activity limitation.

Translational Relevance

The original version of the VF-14 exhibits several limitations that undermines its psychometric validity as a patient-reported outcome measure for patients with LHON.

Developments in the Treatment of Leber Hereditary Optic Neuropathy

PURPOSEOF REVIEW

To outline the current landscape of treatments for Leber hereditary optic neuropathy (LHON) along the therapeutic delivery pipeline, exploring the mechanisms of action and evidence for these therapeutic approaches.

RECENT FINDINGS

Treatments for LHON can be broadly classified as either mutation-specific or mutation-independent. Mutation-specific therapies aim to correct the underlying mutation through the use of a gene-editing platform or replace the faulty mitochondrial DNA-encoded protein by delivering the wild-type gene using a suitable vector. Recent gene therapy clinical trials assessing the efficacy of allotopically expressed MT-ND4 for the treatment of LHON due to the m.11778G > A mutation in MT-ND4 have shown positive results when treated within 12 months of symptom onset. Mutation-independent therapies can have various downstream targets that aim to improve mitochondrial respiration, reduce mitochondrial stress, inhibit or delay retinal ganglion cell apoptosis, and/or promote retinal ganglion cell survival. Idebenone, a synthetic hydrosoluble analogue of co-enzyme Q10 (ubiquinone), is the only approved treatment for LHON. Mutation-independent approaches to gene therapy under pre-clinical investigation for other neurodegenerative disorders may have the potential to benefit patients with LHON. Although approved treatments are presently limited, innovations in gene therapy and editing are driving the expansion of the therapeutic delivery pipeline for LHON.

Solutions to a Radical Problem: Overview of Current and Future Treatment Strategies in Leber's Hereditary Opic Neuropathy

Leber's Hereditary Optic Neuropathy (LHON) is the most common primary mitochondrial DNA disorder. It is characterized by bilateral severe central subacute vision loss due to specific loss of Retinal Ganglion Cells and their axons. Historically, treatment options have been quite limited, but ongoing clinical trials show promise, with significant advances being made in the testing of free radical scavengers and gene therapy. In this review, we summarize management strategies and rational of treatment based on current insights from molecular research. This includes preventative recommendations for unaffected genetic carriers, current medical and supportive treatments for those affected, and emerging evidence for future potential therapeutics.