Peripapillary retinal nerve fibre layer thinning, perfusion changes and optic neuropathy in carriers of Leber hereditary optic neuropathy-associated mitochondrial variants.

BACKGROUND: We investigated Leber hereditary optic neuropathy (LHON) families for variation in peripapillary retinal nerve fibre layer thickness and perfusion, and associated optic nerve dysfunction. METHOD: A group of LHON-affected patients (n=12) and their asymptomatic maternal relatives (n=16) underwent examination including visual acuity (VA), visual-evoked-potential and optic nerve imaging including optical coherence tomography (OCT) and OCT angiography of the peripapillary retinal nerve fibre layer (RNFL). A control sample was also examined (n=10). The software imageJ was used to measure perfusion by assessing vessel density (VD), and statistical software 'R' was used to analyse data. RESULTS: The LHON-affected group (n=12) had significantly reduced peripapillary VD (median 7.9%, p=0.046). Overall, the LHON asymptomatic relatives (n=16) had no significant change in peripapillary VD (p=0.166), though three eyes had VD which fell below the derived normal range at 6% each, with variable VA from normal to blindness; LogMAR median 0, range 0-2.4. In contrast, RNFL thickness was significantly reduced in the LHON-affected group (median 51 µm, p=0.003), and in asymptomatic relatives (median 90 µm, p=0.01), compared with controls (median 101 µm). RNFL thinning had greater specificity compared with reduced perfusion for optic nerve dysfunction in asymptomatic carriers (92% vs 66%). CONCLUSION: Overall, reduced peripapillary retinal nerve fibre layer perfusion was observed in those affected by LHON but was not reduced in their asymptomatic relatives, unlike RNFL thinning which was significantly reduced in both groups versus controls. The presence of RNFL changes was associated with signs of optic neuropathy in asymptomatic relatives.

Optimisation of AAV-NDI1 Significantly Enhances Its Therapeutic Value for Correcting Retinal Mitochondrial Dysfunction.

AAV gene therapy for ocular disease has become a reality with the market authorisation of LuxturnaTM for RPE65-linked inherited retinal degenerations and many AAV gene therapies currently undergoing phase III clinical trials. Many ocular disorders have a mitochondrial involvement from primary mitochondrial disorders such as Leber hereditary optic neuropathy (LHON), predominantly due to mutations in genes encoding subunits of complex I, to Mendelian and multifactorial ocular conditions such as dominant optic atrophy, glaucoma and age-related macular degeneration. In this study, we have optimised the nuclear yeast gene, NADH-quinone oxidoreductase (NDI1), which encodes a single subunit complex I equivalent, creating a candidate gene therapy to improve mitochondrial function, independent of the genetic mutation driving disease. Optimisation of NDI1 (ophNdi1) substantially increased expression in vivo, protected RGCs and increased visual function, as assessed by optokinetic and photonegative response, in a rotenone-induced murine model. In addition, ophNdi1 increased cellular oxidative phosphorylation and ATP production and protected cells from rotenone insult to a significantly greater extent than wild type NDI1. Significantly, ophNdi1 treatment of complex I deficient patient-derived fibroblasts increased oxygen consumption and ATP production rates, demonstrating the potential of ophNdi1 as a candidate therapy for ocular disorders where mitochondrial deficits comprise an important feature.

Optic Nerve Structural and Functional Changes in LHON-Affected and Asymptomatic Maternal Relatives: Association with H and HV Mitochondrial Haplogroups.

Leber Hereditary Optic Neuropathy (LHON) affects a minority of carriers of causative mitochondrial DNA mutations. We investigated a cohort of patients with LHON, including m.11778G>A, m.3460G>A, m.14484T>C and DNAJC30 c.152A>G variants, and their asymptomatic maternal carrier relatives for additional potential associations with vision loss. We assessed visual acuity, optical coherence tomography (OCT) of the peripapillary retinal nerve fibre layer (RNFL), visually evoked potential including P-100 latency, and full mitochondrial genome sequencing. Comparison was made with a reference standard for OCT; European Descent, Heidelberg Engineering ©; and electrophysiology measurements with in-house normative ranges. RNFL was thinned overall in LHON patients (n = 12); median global RNFL −54 µm in the right eye (RE) and −50 µm in the left eye (LE) versus normal, and was found to be normal overall in asymptomatic carriers at +1 µm RE and −2 µm LE (n = 16). In four asymptomatic carriers there was RNFL thinning found either unilaterally or bilaterally; these cases were associated with isolated delay in P-100 latency (25%), delay and reduced visual acuity (50%), or reduced visual acuity without P-100 latency delay (25%). Optic nerve dysfunction was associated with mitochondrial haplogroup H and HV, versus non-H haplogroups, in the asymptomatic carriers (Fisher's exact test, p = 0.05). Our findings suggest that optic nerve abnormalities may be identified in asymptomatic LHON mitochondrial mutation carriers, which may be associated with optic nerve dysfunction. For asymptomatic carriers these findings were associated with mitochondrial haplogroup H and HV.

Neuromyelitis optica spectrum disorders and anti-myelin oligodendrocyte glycoprotein positive optic neuropathies.

AIM: To describe the clinical characteristics and treatments associated with antibody positive optic neuropathies including anti-myelin oligodendrocyte glycoprotein (MOG) and anti-aquaporin 4 (AQP4), alongside diagnostic modalities, investigations, and outcomes. METHODS: A cross-sectional single-centre retrospective case series consisting of 16 patients including 12 anti-MOG positive patients and 4 anti-AQP4 positive patients. Each of these patients had clinical signs and symptoms of optic neuritis and consisted of all patients who had a positive blood antibody result in our centre. Clinical findings including presence of a relative afferent pupillary defect, colour vision and disc assessment were recorded. Structured clinical exam and multimodal imaging was undertaken sequentially on each. Optical coherence tomography (OCT) scanning was preformed to examine the correlation between ganglion cell layer (GCL) thickness and visual acuity (VA) at presentation and as a determinant of final visual outcome in both groups. Initial and long-term treatment is also summarised. RESULTS: A total of 16 patients were included in the study consisting of 12 anti-MOG and 4 anti-AQP4 positive patients. Nine of the 16 patients were female and the average age of onset was 29.2y in the MOG group and 42y in the AQP4 group. There was no statistically significant correlation (Pearson correlation) between GCL thickness and presenting and final VA [r(10)=0.081, P=0.08 and r(10)=0.089, P=0.34 respectively]. The same statistical analysis was performed for the correlation between retinal nerve fibre layer (RNFL) and VA and similar outcomes were observed [r(10)=0.04, P=0.22 and r(10)=0.09, P=0.04]. No correlation was seen for initial RNFL thickness and final visual outcome in this group either [r(2)=0.19, P=0.38]. Visual field testing and radiological findings for each group are described. CONCLUSION: No correlation between initial VA or RNFL and final visual outcome is identified. A broad range of visual field and radiographic findings are identified, a consensus on treatment of neuromyelitis optica spectrum disorders and anti-MOG positive optic neuropathies has yet to be accepted but initial high dose immunosuppression followed by low dose maintenance therapy is favoured.

The Natural History of Leber's Hereditary Optic Neuropathy in an Irish Population and Assessment for Prognostic Biomarkers.

In this study we have assessed the clinical and genetic characteristics of an Irish Leber's hereditary optic neuropathy (LHON) cohort and assessed for useful biomarkers of visual prognosis. We carried out a retrospective review of clinical data of patients with genetically confirmed LHON presenting to an Irish tertiary referral ophthalmic hospital. LHON diagnosis was made on classic clinical signs with genetic confirmation. Alternate diagnoses were excluded with serological investigations and neuro-imaging. Serial logarithm of the minimum angle of resolution (logMAR) visual acuity (VA) was stratified into 'on-chart' for logMAR 1.0 or better and 'off-chart' if worse than logMAR 1.0. Serial optical coherence tomography scans of the retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) monitored structure. Idebenone-treated and untreated patients were contrasted. Statistical analyses were performed to assess correlations of presenting characteristics with final VA. Forty-four patients from 34 pedigrees were recruited, of which 87% were male and 75% harboured the 11778 mutation. Legal blindness status was reached in 56.8% of patients by final review (mean 74 months). Preservation of initial nasal RNFL was the best predictor of on-chart final VA. Females had worse final VA than males and patients presenting at < 20 years of age had superior final VA. Idebenone therapy (50% of cohort) yielded no statistically significant benefit to final VA, although study design precludes definitive comment on efficacy. The reported cases represent the calculated majority of LHON pedigrees in Ireland. Visual outcomes were universally poor; however, VA may not be the most appropriate outcome measure and certain patient-reported outcome measures may be of more use when assessing future LHON interventions.

Longitudinal Assessment Using Optical Coherence Tomography in Patients with Friedreich's Ataxia.

Ocular abnormalities occur frequently in Friedreich's ataxia (FRDA), although visual symptoms are not always reported. We evaluated a cohort of patients with FRDA to characterise the clinical phenotype and optic nerve findings as detected with optical coherence tomography (OCT). A total of 48 patients from 42 unrelated families were recruited. Mean age at onset was 13.8 years (range 4-40), mean disease duration 19.5 years (range 5-43), mean disease severity as quantified with the Scale for the Assessment and Rating of Ataxia 22/40 (range 4.5-38). All patients displayed variable ataxia and two-thirds had ocular abnormalities. Statistically significant thinning of average retinal nerve fibre layer (RNFL) and thinning in all but the temporal quadrant compared to controls was demonstrated on OCT. Significant RNFL and macular thinning was documented over time in 20 individuals. Disease severity and visual acuity were correlated with RNFL and macular thickness, but no association was found with disease duration. Our results highlight that FDRA is associated with subclinical optic neuropathy. This is the largest longitudinal study of OCT findings in FRDA to date, demonstrating progressive RNFL thickness decline, suggesting that RNFL thickness as measured by OCT has the potential to become a quantifiable biomarker for the evaluation of disease progression in FRDA.

Benign intracranial hypertension associated with inhaled corticosteroids in a child with asthma.

A 13-year-old male asthmatic presented to the general paediatric clinic with papilloedema identified following a check-up with his optician due to blurred vision. His asthma was well controlled on a moderate dose of inhaled corticosteroid and there had been no recent increase or decrease in the dose. A diagnosis of benign intracranial hypertension (BIH) was made based on a raised cerebrospinal fluid opening pressure, papilloedema, a normal neurological examination and normal neuroimaging. The only associated risk factor was his inhaled corticosteroids. He was commenced on acetazolamide and the inhaled corticosteroid dose was reduced, resulting in resolution of his papilloedema. This case serves to highlight that steroid side effects including BIH may occur at moderate doses of inhaled corticosteroids and that inhaled corticosteroid dose should be regularly reviewed and decreased to the lowest dose that maintains asthma control.

Neurophysiological and ophthalmological findings of SPG7-related spastic ataxia: a phenotype study in an Irish cohort.

BACKGROUND: Mutations in SPG7 are increasingly identified as a common cause of spastic ataxia. We describe a cohort of Irish patients with recessive SPG7-associated phenotype. METHODS: Comprehensive phenotyping was performed with documentation of clinical, neurophysiological, optical coherence tomography (OCT) and genetic data from individuals with SPG7 attending two academic neurology units in Dublin, including the National Ataxia Clinic. RESULTS: Thirty-two symptomatic individuals from 25 families were identified. Mean age at onset was 39.1 years (range 12-61), mean disease duration 17.8 years (range 5-45), mean disease severity as quantified with the scale for the assessment and rating of ataxia 9/40 (range 3-29). All individuals displayed variable ataxia and spasticity within a spastic-ataxic phenotype, and additional ocular abnormalities. Two had spasmodic dysphonia and three had colour vision deficiency. Brain imaging consistently revealed cerebellar atrophy (n = 29); neurophysiology demonstrated a length-dependent large-fibre axonal neuropathy in 2/27 studied. The commonest variant was c.1529C > T (p.Ala510Val), present in 21 families. Five novel variants were identified. No significant thinning of average retinal nerve fibre layer (RNFL) was demonstrated on OCT (p = 0.61), but temporal quadrant reduction was evident compared to controls (p < 0.05), with significant average and temporal RNFL decline over time. Disease duration, severity and visual acuity were not correlated with RNFL thickness. CONCLUSIONS: Our results highlight that recessive SPG7 mutations may account for spastic ataxia with peripheral neuropathy in only a small proportion of patients. RNFL abnormalities with predominant temporal RNFL reduction are common and OCT should be considered part of the routine assessment in spastic ataxia.

Optimized OPA1 Isoforms 1 and 7 Provide Therapeutic Benefit in Models of Mitochondrial Dysfunction.

Optic Atrophy 1 (OPA1) is a mitochondrially targeted GTPase that plays a pivotal role in mitochondrial health, with mutations causing severe mitochondrial dysfunction and typically associated with Dominant Optic Atrophy (DOA), a progressive blinding disease involving retinal ganglion cell loss and optic nerve damage. In the current study, we investigate the use of codon-optimized versions of OPA1 isoform 1 and 7 as potential therapeutic interventions in a range of in vitro and in vivo models of mitochondrial dysfunction. We demonstrate that both isoforms perform equally well in ameliorating mitochondrial dysfunction in OPA1 knockout mouse embryonic fibroblast cells but that OPA1 expression levels require tight regulation for optimal benefit. Of note, we demonstrate for the first time that both OPA1 isoform 1 and 7 can be used independently to protect spatial visual function in a murine model of retinal ganglion cell degeneration caused by mitochondrial dysfunction, as well as providing benefit to mitochondrial bioenergetics in DOA patient derived fibroblast cells. These results highlight the potential value of OPA1-based gene therapy interventions.

Outcomes of endoscopic orbital decompression for graves' ophthalmopathy.

BACKGROUND/AIMS: We assess outcomes of endoscopic orbital decompression for Graves' ophthalmopathy. METHODS: A review of endoscopic orbital decompressions of the medial and partial inferior wall between July 2004 and July 2017 was carried out. Outcome was assessed by comparing pre- and post-operative measurements of exophthalmometry and visual acuity. Results were evaluated by repeated measures analysis of variance. RESULTS: A total of 41 orbits in 25 patients underwent endoscopic orbital decompression for Graves' ophthalmopathy in the time period; however, six orbits in three patients had insufficient data for inclusion. Eleven patients required concurrent septoplasty to allow access. Measurements were taken at a mean of 11 days, 32 days, and 95 days post-operatively. Reduction in mean proptosis was 2.81 mm at 1-month post-decompression and 3.26 mm at 3 months. There was no significant difference between those treated for compressive optic neuropathy compared with those treated for cosmetic reasons. Colour vision by Ishihara plate improved significantly by a mean score of 2.67 post-operatively. Using LogMAR conversion for visual acuity, measured by a best-corrected Snellen chart, improvement of 0.18 was achieved at 1-month post-decompression, equivalent to approximately two lines on the Snellen chart. There was minimal (0.04) further improvement at 3 months. The improvement in visual acuity was greater in cases treated for compressive optic neuropathy than cosmesis, but this did not reach statistical significance (p = 0.06). Three cases required revision surgery. Diplopia disimproved or developed in four cases and squint surgery was required in three cases. CONCLUSIONS: Endoscopic orbital decompression offers an effective, safe and minimally invasive treatment for Graves' ophthalmopathy. There is a trend towards continued improvement in outcomes over the course of 3 months post-operatively.

Effects of vitamin D3 in clinically isolated syndrome and healthy control participants: A double-blind randomised controlled trial.

BACKGROUND: Lowserum vitamin D levels are associated with susceptibility to, and severity of, multiple sclerosis. High dose vitamin D has been proposed as a potential immunomodulator in multiple sclerosis. OBJECTIVES: We performed a single centre, investigator-led, exploratory, double-blind, randomised, placebo controlled, trial of vitamin D3 in clinically isolated syndrome and healthy control participants to assess its immunological effects. Secondary end-points included clinical and magnetic resonance imaging outcomes and safety. METHODS: Clinically isolated syndrome patients and healthy control participants were randomised to: placebo, 5000 IU or 10,000 IU vitamin D3/day (Vigantol oil). Study duration was 24 weeks. RESULTS: The trial did not meet its primary end point, with no difference in the frequency of pro-inflammatory CD4+ T cells (interleukin (IL)-17+/interferon (IFN)-γ+) seen. A higher level of disease freedom (67% versus 50%) was seen in those with serum 1,25 (OH) vitamin D levels>100 nmol/l but this did not reach significance. High dose vitamin D3 was well tolerated with no safety signal. CONCLUSIONS: High dose vitamin D3 over 24 weeks was well tolerated but without immunological, magnetic resonance imaging or clinical evidence of benefit. The hypothesised therapeutic effects in clinically isolated syndrome or multiple sclerosis patients may require longer periods of administration or may only be seen in patients treated with vitamin D3 as an adjunct to established disease modifying therapies.

Anoctamin 10-Related Autosomal Recessive Cerebellar Ataxia: Comprehensive Clinical Phenotyping of an Irish Sibship.

The autosomal recessive cerebellar ataxias are a heterogeneous group of neurodegenerative disorders. Mutations in the anoctamin 10 gene (ANO10) recently have been identified as a cause of autosomal recessive spinocerebellar ataxia type 10. Comprehensive phenotypic data are provided on 3 siblings with homozygous ANO10 mutations, including detailed ocular and cognitive assessments and bladder involvement not previously described in the literature. Data also are provided on unblinded therapy with coenzyme Q10, previously reported as a possible therapy in ANO10-related ataxia. A genetic diagnosis in this family was obtained through next-generation sequencing techniques after over 10 years of expensive sequencing of individual genes using the traditional Sanger approach. Greater commercial availability of gene panels will improve the ability to obtain a genetic diagnosis in the uncommon "non-Friedreich's" recessive ataxias. Clinical recognition of these recessive ataxic syndromes will also inevitably improve as the full phenotypic spectrum is identified.

Dose-related effects of vitamin D on immune responses in patients with clinically isolated syndrome and healthy control participants: study protocol for an exploratory randomized double- blind placebo-controlled trial.

BACKGROUND: There is increasing evidence linking vitamin D deficiency to both susceptibility to, and severity of, multiple sclerosis (MS). Patients with the clinically isolated syndrome represent the initial presentation of a demyelinating disorder, and those with asymptomatic lesions on magnetic resonance imaging (MRI) are at risk of progression to clinically definite MS. The aims of this study are to examine the immunologic effects of vitamin D in both healthy individuals and in patients with clinically isolated syndrome, and in the latter group the effects on disease progression assessed by MRI and clinical measures. METHODS/DESIGN: This is a single-center double-blind randomized placebo-controlled clinical trial. The primary endpoint is the immunologic effects of two doses of vitamin D compared with placebo over 24 weeks in both healthy control participants and patients presenting with the clinically isolated syndrome. Healthy control participants (n = 39) and patients with clinically isolated syndrome (n = 45) will be randomized to one of three arms, namely 1) vitamin D 5,000 IU daily, 2) vitamin D 10,000 IU daily, or 3) placebo, and followed up for 24 weeks. In both patients and healthy control participants, the primary outcome will be immunologic measures of the frequency of CD4 T-cell subsets and cytokine responses in peripheral blood mononuclear cells, assessed at baseline, and after 16 and 24 weeks of treatment. Secondary endpoints, in the patients with clinically isolated syndrome, will be relapse activity, and the number of new T2 lesions and gadolinium-enhancing lesions assessed by MRI in the two vitamin D-treated groups compared with the placebo-treated group over the 24 weeks of the study. TRIAL REGISTRATION: EU Clinical Trials Register: EudraCT: 2012-000635-68. ClinicalTrials.gov identifier: NCT01728922.

Prognostic indicators and outcome measures for surgical removal of symptomatic nonadvanced cataract.

OBJECTIVES: To report changes in perceived visual functioning after surgery for symptomatic cataract with preoperative corrected distance visual acuity [CDVA] of 0.4 logMAR or better (Snellen equivalent, 20/50) and to investigate the relationship between any observed changes and preoperative physical characteristics and psychophysical consequences of the lens opacity and any changes in psychophysical findings after the procedure. METHODS: Eighty-five patients with cataract completed a validated questionnaire concerning functional vision satisfaction and a series of visual performance assessments before and 2 months after cataract surgery. The lens optical density and Lens Opacities Classification System III score of the cataract were recorded. Correlations between changes in the Rasch-analyzed questionnaire score and changes in visual performance after cataract surgery, as well as preoperative psychophysical measures, lens optical density, and Lens Opacities Classification System III score, were determined. RESULTS: The mean (SD) questionnaire score improved from 2.15 (0.36) to 1.54 (0.41) (P < .001). The preoperative questionnaire score (r = -0.44), preoperative mesopic glare disability [GD] (at 1.5 cycles per degree [cpd] [r = 0.34] and 3.0 cpd [r = 0.27]), and preoperative photopic GD (at 1.5 cpd [r = 0.24] and 3.0 cpd [r = 0.30]) showed statistically significant correlations with perceived improvements in visual functioning after surgery (P < .05). Changes in perceived visual functioning correlated significantly with changes in mesopic GD (at 1.5 cpd [r = -0.43] and 3.0 cpd [r = -0.28]; P < .05) and photopic GD (at 1.5 cpd [r = -0.24] and 3.0 cpd [r = -0.39]; P < .05). Neither preoperative CDVA nor change in CDVA after surgery correlated significantly with perceived improvement in visual functioning after the procedure (P > .05 for both). CONCLUSION: Psychophysical tests alternative to CDVA better represent improvements in self-reported visual functioning following removal of symptomatic nonadvanced cataract.

Effect on refractive outcomes after cataract surgery of intraocular lens constant personalization using the Haigis formula.

PURPOSE: To quantify the effect on refractive outcomes after cataract surgery of personalization of Haigis intraocular lens (IOL) constants for a given surgeon-IOL combination. SETTING: Institute of Eye Surgery and Institute of Vision Research, Whitfield Clinic, Butlerstown North, Waterford, Ireland. METHODS: Personalization of Haigis IOL constants was performed using a series of 248 suitable eyes after biometry by partial coherence interferometry (IOLMaster) and IOL prediction based on optimized IOL constants derived from pooled data from the User Group for Laser Interference Biometry web site. A mean error of prediction and a mean absolute error were then calculated using the personalized IOL constants and compared with those derived using optimized IOL constants, allowing evaluation and quantification of the maximum realizable refractive benefits (if any) of personalization. RESULTS: There was no statistically significant difference between personalized and optimized Haigis IOL constants in absolute error or the proportion of eyes within +/-1.00 diopters (D), +/-0.50 D, or +/-0.25 D of the target postoperative refraction in all eyes, short eyes (axial length [AL] <22 mm; n = 19), average eyes (AL > or =22 mm and <24.5 mm; n = 149), or long eyes (AL >24.5 mm; n = 46) (all P>.05, McNemar test). Ten eyes with a short AL had a smaller absolute error (by > or =0.30 D) in association with personalized IOL constants. CONCLUSION: Personalized Haigis IOL constants showed marginal, but statistically nonsignificant, refractive advantages over optimized Haigis IOL constants, but only in eyes with a short AL. FINANCIAL DISCLAIMER: No author has a financial or proprietary interest in any material or method mentioned.

The relationship between HLA-DRB1 alleles and optic neuritis in Irish patients and the risk of developing multiple sclerosis.

AIMS: To investigate the role of the major histocompatibility complex in Irish patients with optic neuritis (ON) and determine whether HLA-DRB1 genotypes are a risk factor for the development of multiple sclerosis (MS) in such patients. METHOD: All patients were Caucasian, had Irish ancestry and had MRI of brain and optic nerves within 2-3 weeks of presentation. Patients were referred to a neurologist if MRI findings were consistent with a diagnosis of MS. HLA-DRB1 allele and phenotype frequencies for 78 patients with a clinical diagnosis of acute ON were compared with those for 250 healthy bone marrow donors. RESULTS: An ON/MS positive patient was 3.4 times more likely than an ON/MS negative patient to be DRB1*15 positive. No difference in age profile was detected between ON/MS positive and ON/MS negative patients or between the ON male and female subgroups. No gender or HLA-DRB1 association was identified for ON/MS negative patients. Female gender was significantly increased among ON/MS positive patients with a p value of 0.0053. CONCLUSIONS: DRB1*15 is a significant predisposing factor for ON. This ON patient cohort has also provided an opportunity to evaluate the relationship of HLA genotype with the risk of MS development. The findings of this study indicate that Irish individuals presenting with ON and who are HLA DRB1*15 positive have a higher risk than HLA DRB1*15 negative patients of presenting with MRI findings indicative of MS. This study has also demonstrated that female gender is a risk factor for developing MS in the Irish population.