Quantification of peripapillary nerve fibre elevation and its association with axial length, optic disc tilt, and parapapillary atrophy area in young, healthy eyes

BACKGROUND

Eyes with peripapillary nerve fibre elevation (pNFE) may have a gap between the optic nerve papillary margin on colour fundus photography and Bruch's membrane opening on cross-sectional optical coherence tomography (OCT). This study was conducted to evaluate the quantification of the height of pNFE in young healthy eyes and examine the relationship between pNFE height and axial length.

METHODS

A prospective, observational, cross-sectional study was performed involving 117 right eyes. All participants (mean age 25.8 years) underwent comprehensive ophthalmologic examination involving axial length, fundus photography, and peripapillary and optic disc OCT. pNFE height was defined as the distance between the retinal surface plane and the upper edge of the pNFE in optic disc cross-sectional OCT images. Optic disc tilt was evaluated using a sine curve on retinal nerve fibre layer B-scan images. Parapapillary atrophy (PPA) area in colour fundus images was calculated using ImageJ and corrected using Bennett's formula. We evaluated relationships between pNFE height, axial length, optic disc papillary tilt, and PPA area using Spearman's correlation analysis.

RESULTS

Sixty-five eyes had pNFE, with a mean pNFE height of 84.7 μm. pNFE height was significantly positively correlated with axial length (r = 0.32, p < 0.001), optic disc tilt (r = 0.25, p = 0.008), and PPA area (r = 0.27, p = 0.004).

CONCLUSIONS

pNFE is not rare in young healthy eyes. Eyes with higher pNFE had a longer axial length and larger optic disc tilt and PPA area.

Structural interhemispheric connectivity defects in mouse models of BBSOAS: Insights from high spatial resolution 3D white matter tractography

White matter (WM) tract formation and axonal pathfinding are major processes in brain development allowing to establish precise connections between targeted structures. Disruptions in axon pathfinding and connectivity impairments will lead to neural circuitry abnormalities, often associated with various neurodevelopmental disorders (NDDs). Among several neuroimaging methodologies, Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging (MRI) technique that has the advantage of visualizing in 3D the WM tractography of the whole brain non-invasively. DTI is particularly valuable in unpinning structural tract connectivity defects of neural networks in NDDs. In this study, we used 3D DTI to unveil brain-specific tract defects in two mouse models lacking the Nr2f1 gene, which mutations in patients have been proven to cause an emerging NDD, called Bosch-Boonstra-Schaaf Optic Atrophy (BBSOAS). We aimed to investigate the impact of the lack of cortical Nr2f1 function on WM morphometry and tract microstructure quantifications. We found in both mutant mice partial loss of fibers and severe misrouting of the two major cortical commissural tracts, the corpus callosum, and the anterior commissure, as well as the two major hippocampal efferent tracts, the post-commissural fornix, and the ventral hippocampal commissure. DTI tract malformations were supported by 2D histology, 3D fluorescent imaging, and behavioral analyses. We propose that these interhemispheric connectivity impairments are consistent in explaining some cognitive defects described in BBSOAS patients, particularly altered information processing between the two brain hemispheres. Finally, our results highlight 3DDTI as a relevant neuroimaging modality that can provide appropriate morphometric biomarkers for further diagnosis of BBSOAS patients.

Infantile onset encephalomyopathy, retinopathy, optic atrophy, and mitochondrial DNA depletion associated with a novel pathogenic DHX16 variant

We studied a patient with mitochondrial DNA depletion in skeletal muscle and a multiorgan phenotype, including fatal encephalomyopathy, retinopathy, optic atrophy, and sensorineural hearing loss. Instead of pathogenic variants in the mitochondrial maintenance genes, we identified previously unpublished variant in DHX16 gene, a de novo heterozygous c.1360C>T (p. Arg454Trp). Variants in DHX16 encoding for DEAH-box RNA helicase have previously been reported only in five patients with a phenotype called as neuromuscular oculoauditory syndrome including developmental delay, neuromuscular symptoms, and ocular or auditory defects with or without seizures. We performed functional studies on patient-derived fibroblasts and skeletal muscle revealing, that the DHX16 expression was decreased. Clinical features together with functional data suggest, that our patient's disease is associated with a novel pathogenic DHX16 variant, and mtDNA depletion could be a secondary manifestation of the disease.

Variants in the WDR45 Gene Within the OPA-2 Locus Associate With Isolated X-Linked Optic Atrophy

Purpose

To describe clinical and molecular findings of two families with X-linked optic atrophy and present two new pathogenic variants in the WDR45 gene.

Methods

Case series and molecular analysis of two families of Jewish Ashkenazi descent with early onset bilateral optic atrophy. Whole-exome sequencing (WES) and bioinformatic analysis were performed, followed by Sanger sequencing and segregation analysis.

Results

In both families, male siblings (three in family 1, two in family 2) had early-onset isolated bilateral optic atrophy. The sibling's healthy mother (and in the second family also one healthy sister) had a mild presentation, suggesting a carrier state and an X-linked inheritance pattern. All participants were otherwise healthy, apart from mild learning disabilities and autism spectrum disorder in two siblings of the second family. Variants in known optic atrophy genes were excluded. Analysis revealed a point variant in the WDR45 gene-a missense variant in the first family, NM_001029896.2:c.107C>A; NP_001025067.1:p.Pro36His (variant ID: 1704205), and a splice site variant in the second family, NM_001029896.2:c.236-1G>T; NP_009006.2:p.Val80Leu (variant ID: 1704204), located on Xp11.23 (OPA2 locus). Both variants are novel and predicted as pathogenic. In both families, the variant was seen with full segregation with the disease, occurring in all affected male participants and in one allele of the carrier females, as well as none of the healthy participants.

Conclusions

Among two families with isolated X-linked optic atrophy, molecular analysis revealed novel variants in the WDR45 gene in full segregation with the disease. This gene resides within the OPA2 locus, previously described to associate with X-linked optic atrophy. Taken together, these findings suggest that certain pathogenic variants in the WDR45 gene are associated with isolated X-linked optic atrophy.

GLP-1R agonists demonstrate potential to treat Wolfram syndrome in human preclinical models

AIMS/HYPOTHESIS

Wolfram syndrome is a rare autosomal recessive disorder caused by pathogenic variants in the WFS1 gene. It is characterised by insulin-dependent diabetes mellitus, optic nerve atrophy, diabetes insipidus, hearing loss and neurodegeneration. Considering the unmet treatment need for this orphan disease, this study aimed to evaluate the therapeutic potential of glucagon-like peptide 1 receptor (GLP-1R) agonists under wolframin (WFS1) deficiency with a particular focus on human beta cells and neurons.

METHODS

The effect of the GLP-1R agonists dulaglutide and exenatide was examined in Wfs1 knockout mice and in an array of human preclinical models of Wolfram syndrome, including WFS1-deficient human beta cells, human induced pluripotent stem cell (iPSC)-derived beta-like cells and neurons from control individuals and individuals affected by Wolfram syndrome, and humanised mice.

RESULTS

Our study shows that the long-lasting GLP-1R agonist dulaglutide reverses impaired glucose tolerance in WFS1-deficient mice, and that exenatide and dulaglutide improve beta cell function and prevent apoptosis in different human WFS1-deficient models including iPSC-derived beta cells from people with Wolfram syndrome. Exenatide improved mitochondrial function, reduced oxidative stress and prevented apoptosis in Wolfram syndrome iPSC-derived neural precursors and cerebellar neurons.

CONCLUSIONS/INTERPRETATION

Our study provides novel evidence for the beneficial effect of GLP-1R agonists on WFS1-deficient human pancreatic beta cells and neurons, suggesting that these drugs may be considered as a treatment for individuals with Wolfram syndrome.

NDUFS3 depletion permits complex I maturation and reveals TMEM126A/OPA7 as an assembly factor binding the ND4-module intermediate

Complex I (CI) is the largest enzyme of the mitochondrial respiratory chain, and its defects are the main cause of mitochondrial disease. To understand the mechanisms regulating the extremely intricate biogenesis of this fundamental bioenergetic machine, we analyze the structural and functional consequences of the ablation of NDUFS3, a non-catalytic core subunit. We show that, in diverse mammalian cell types, a small amount of functional CI can still be detected in the complete absence of NDUFS3. In addition, we determine the dynamics of CI disassembly when the amount of NDUFS3 is gradually decreased. The process of degradation of the complex occurs in a hierarchical and modular fashion in which the ND4 module remains stable and bound to TMEM126A. We, thus, uncover the function of TMEM126A, the product of a disease gene causing recessive optic atrophy as a factor necessary for the correct assembly and function of CI.

Optic Atrophy and Inner Retinal Thinning in CACNA1F-related Congenital Stationary Night Blindness

Hemizygous pathogenic variants in CACNA1F lead to defective signal transmission from retinal photoreceptors to bipolar cells and cause incomplete congenital stationary night blindness in humans. Although the primary defect is at the terminal end of first-order neurons (photoreceptors), there is limited knowledge of higher-order neuronal changes (inner retinal) in this disorder. This study aimed to investigate inner retinal changes in CACNA1F-retinopathy by analyzing macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness and optic disc pallor in 22 subjects with molecularly confirmed CACNA1F-retinopathy. Detailed ocular phenotypic data including distance and color vision, refraction and electroretinogram (ERG) were collected. Distance vision was universally reduced (mean: 0.42 LogMAR), six had abnormal color vision and myopia was common (n = 15; mean: −6.32 diopters). Mean GCL-IPL thickness was significantly lower in patients (55.00 µm) compared to age-matched controls (n = 87; 84.57 µm; p << 0.001). The GCL-IPL thickness correlated with scotopic standard (p = 0.04) and bright-flash (p = 0.014) ERG b/a ratios and photopic b-wave amplitudes (p = 0.05). Twenty-one patients had some degree of disc pallor (bilateral in 19). Fifteen putative disease-causing, including five novel variants were identified. This study establishes macular inner retinal thinning and optic atrophy as characteristic features of CACNA1F-retinopathy, which are independent of myopia and could impact potential future treatment strategies.

Recessive ACO2 variants as a cause of isolated ophthalmologic phenotypes

The mitochondrial aconitase gene (ACO2) encodes an enzyme that catalyzes the conversion of citrate to isocitrate in the tricarboxylic acid cycle. Biallelic variants in ACO2 are purported to cause two distinct disorders: infantile cerebellar-retinal degeneration (ICRD) which is characterized by CNS abnormalities, neurodevelopmental phenotypes, optic atrophy and retinal degeneration; and optic atrophy 9 (OPA9), characterized by isolated ophthalmologic phenotypes including optic atrophy and low vision. However, some doubt remains as to whether biallelic ACO2 variants can cause isolated ophthalmologic phenotypes. A review of the literature revealed five individuals from three families who carry biallelic ACO2 variants whose phenotypes are consistent with OPA9. Here, we describe a brother and sister with OPA9 who are compound heterozygous for novel missense variants in ACO2; c.[487G>T];[1894G>A], p.[(Val163Leu)];[(Val632Met)]. A review of pathogenic ACO2 variants revealed that those associated with OPA9 are distinct from those associated with ICRD. Missense variants associated with either OPA9 or ICRD do not cluster in distinct ACO2 domains, making it difficult to predict the severity of a variant based on position alone. We conclude that biallelic variants in ACO2 can cause the milder OPA9 phenotype, and that the OPA9-related ACO2 variants identified to date are distinct from those that cause ICRD.

Martsolf syndrome with novel mutation in the TBC1D20 gene in a family from Iran

Warburg Micro syndrome and Martsolf syndrome are phenotypically overlapping autosomal recessive conditions characterized by multiple organ abnormalities involving the ocular, nervous, and endocrine systems. Warburg Micro syndrome, the more severe of the two conditions, is caused by loss of function mutations in RAB3GAP1, RAB3GAP2, RAB18, and TBC1D20 genes, whereas Martsolf syndrome has been attributed to less damaging mutations in RAB3GAP1 and RAB3GAP2 genes. We report the clinical description and molecular characterization of a consanguineous Iranian family with two siblings, a male and a female, with dysmorphic features, bilateral congenital cataracts, optic nerve atrophy, congenital glaucoma, mild to moderate intellectual disability, seizures, hypogonadism, and mild osteoporosis. Spastic quadriplegia with contractures was observed in the male patient, while the female patient showed only mild hyperreflexia. Magnetic resonance imaging scans performed in the male patient showed a normal brain structure. Both siblings had neither microcephaly nor postnatal growth retardation. Whole exome sequencing identified a novel homozygous nonsense mutation [c.1060C>T; p.(Arg354Ter)] in the TBC1D20 gene in both siblings and confirmed the heterozygous carrier status of both parents. This report describes a novel mutation in the TBC1D20 gene in two Iranian patients with Martsolf syndrome, further extending the allelic heterogeneity and phenotypic spectrum of this rare condition. The genotype and phenotype of the patients are compared with those of Martsolf syndrome and Warburg Micro syndrome patients reported in the literature.

Segregation of two variants suggests the presence of autosomal dominant and recessive forms of WFS1-related disease within the same family: expanding the phenotypic spectrum of Wolfram Syndrome

BACKGROUND

WFS1 was initially described as causative agent of autosomal recessive (AR) Wolfram syndrome, a childhood-onset disorder involving diabetes, optic atrophy, hearing loss and neurodegenerative features. However, the discovery of autosomal dominant (AD) disorders caused by this gene has resulted in clinical counselling and result interpretation challenges.

OBJECTIVE

We seek to report a family that appears to segregate dominant and recessive forms of WFS1-related disease.

METHODS/RESULTS

A 19-year-old woman presented with progressive childhood sensorineural hearing loss and recent optic atrophy, with biallelic mutations in WFS1: c.2486T>C (likely pathogenic) and c.2470G>A (uncertain significance). Her A1C was normal. Her sister carried the same variants and had a similar phenotype. Their father carried c.2486T>C and was found to have mild-moderate hearing loss but no optic atrophy or neurological symptoms. The mother carried c.2470G>A and had a normal audiogram and ophthalmological exam. Providing anticipatory guidance for this family was difficult given the phenotypic variability of WFS1-related disorders and the uncertainty surrounding whether the inheritance pattern was AR or AD.

CONCLUSION

The clinical correlation of the variants identified in this family suggests an AR Wolfram-like syndrome, without the typical diabetes mellitus or diabetes insipidus nor neurological decline. To our knowledge, this is a novel WFS1-related phenotype.

Hereditary Myelopathies

PURPOSE OF REVIEW

Hereditary myelopathies are very diverse genetic disorders, and many of them represent a widespread neurodegenerative process rather than isolated spinal cord dysfunction. This article reviews various types of inherited myelopathies, with emphasis on hereditary spastic paraplegias and spastic ataxias.

RECENT FINDINGS

The ever-growing number of myelopathy-causing genes and broadening of phenotype-genotype correlations makes the molecular diagnosis of inherited myelopathies a daunting task. This article emphasizes the main phenotypic clusters among inherited myelopathies that can facilitate the diagnostic process. This article focuses on newly identified genetic causes and the most important identifying clinical features that can aid the diagnosis, including the presence of a characteristic age of onset and additional neurologic signs such as leukodystrophy, thin corpus callosum, or amyotrophy.

SUMMARY

The exclusion of potentially treatable causes of myelopathy remains the most important diagnostic step. Syndromic diagnosis can be supported by molecular diagnosis, but the genetic diagnosis at present does not change the management. Moreover, a negative genetic test does not exclude the diagnosis of a hereditary myelopathy because comprehensive molecular testing is not yet available, and many disease-causing genes remain unknown.

CIRCINATE PARTITION-LIKE FINDINGS ON CONE MOSAIC IMAGED BY ADAPTIVE OPTICS SCANNING LASER OPHTHALMOSCOPY IN EYES WITH INNER NUCLEAR LAYER MICROCYSTIC CHANGES

PURPOSE

To report cases that showed partition-like, dark areas in the cone mosaic on adaptive optics scanning laser ophthalmoscopy (AO-SLO) images in eyes with inner nuclear layer (INL) microcystic changes.

METHODS

Eyes with INL microcystic changes were imaged by prototype AO-SLO.

RESULTS

An eye with Leber hereditary optic neuropathy, an eye with traumatic optic neuropathy, and an eye with retinitis pigmentosa that showed microcystic lesions in the INL were imaged by AO-SLO. The images revealed characteristic, dark, partition-like lesions in the cone mosaic of all the eyes in areas where microcystic changes in the INL were shown by spectral domain optical coherence tomography. The AO-SLO findings in eyes with optic neuropathy were quite similar in shape and size to those seen in eyes with retinitis pigmentosa.

CONCLUSION

We report cases that manifest dark, partition-like areas in the cone mosaic on AO-SLO images. Microcystic lesions in the INL may affect the images of the cone mosaic.

Identification of a missense variant in the WFS1 gene that causes a mild form of Wolfram syndrome and is associated with risk for type 2 diabetes in Ashkenazi Jewish individuals

AIMS/HYPOTHESIS

Wolfram syndrome is a rare, autosomal recessive syndrome characterised by juvenile-onset diabetes and optic atrophy and is caused by bi-allelic mutations in the WFS1 gene. In a recent sequencing study, an individual with juvenile-onset diabetes was observed to be homozygous for a rare missense variant (c.1672C>T, p.R558C) in the WFS1 gene. The aim of this study was to perform the genetic characterisation of this variant and to determine whether it is causal for young-onset diabetes and Wolfram syndrome.

METHODS

We analysed the allele frequency of the missense variant in multiple variant databases. We genotyped the variant in 475 individuals with type 1 diabetes and 2237 control individuals of Ashkenazi Jewish ancestry and analysed the phenotypes of homozygotes. We also investigated the association of this variant with risk for type 2 diabetes using genotype and sequence data for type 2 diabetes cases and controls.

RESULTS

The missense variant demonstrated an allele frequency of 1.4% in individuals of Ashkenazi Jewish ancestry, 60-fold higher than in other populations. Genotyping of this variant in 475 individuals diagnosed with type 1 diabetes identified eight homozygotes compared with none in 2237 control individuals (genotype relative risk 135.3, p = 3.4 × 10^-15). The age at diagnosis of diabetes for these eight individuals (17.8 ± 8.3 years) was several times greater than for typical Wolfram syndrome (5 ± 4 years). Further, optic atrophy was observed in only one of the eight individuals, while another individual had the Wolfram syndrome-relevant phenotype of neurogenic bladder. Analysis of sequence and genotype data in two case-control cohorts of Ashkenazi ancestry demonstrated that this variant is also associated with an increased risk of type 2 diabetes in heterozygotes (OR 1.81, p = 0.004).

CONCLUSIONS/INTERPRETATION

We have identified a low-frequency coding variant in the WFS1 gene that is enriched in Ashkenazi Jewish individuals and causes a mild form of Wolfram syndrome characterised by young-onset diabetes and reduced penetrance for optic atrophy. This variant should be considered for genetic testing in individuals of Ashkenazi ancestry diagnosed with young-onset non-autoimmune diabetes and should be included in Ashkenazi carrier screening panels.

Macular choroidal thickness and peripapillary retinal nerve fiber layer thickness in normal adults and patients with optic atrophy due to acute idiopathic demyelinating optic neuritis

Purpose

To evaluate the association between macular choroidal thickness and peripapillary RNFL thickness in patients with optic atrophy due to acute idiopathic demyelinating optic neuritis and in normal controls using spectral domain optical coherence tomography (SD-OCT).

Methods

We performed SD-OCT peripapillary RNFL circular scan centered on the optic disc with horizontal and vertical crosshair scans through the fovea using the enhanced depth technique in 62 eyes with optic atrophy due to acute idiopathic demyelinating optic neuritis and 86 eyes of normal controls. The association between RNFL thickness and macular choroidal thickness measurements was assessed.

Results

The mean age was 43 ± 14 years (mean ± SD) in patients with optic atrophy and 45 ± 16 years in healthy controls (p = 0.791). There was a significant association between nasal peripapillary RNFL thickness and choroidal thickness at 3.0 mm nasal to the foveal center in patients with optic atrophy in multivariate analysis (estimate = 1.398, p = 0.011). In controls, there were significant associations between global average, superior, and inferior peripapillary RNFL thickness and choroidal thickness at 3.0 mm superior to the foveal center (estimate = -60.112, p = 0.044, estimate = 15.821, p = 7.312, and estimate = 15.203, p = 7.222, respectively).

Conclusions

Our SD-OCT data revealed that there was a significant association between peripapillary RNFL thickness and macular choroidal thickness in patients with optic atrophy due to acute idiopathic demyelinating optic neuritis and in controls, although the mechanism remained unclear. The difference in the pattern of association between patients with optic atrophy and controls suggests that optic atrophy caused by acute idiopathic demyelinating optic neuritis could affect the pattern of association between peripapillary RNFL thickness and macular choroidal thickness.

Evaluation of Optic Nerve with Strain and Shear Wave Elastography in Patients with Behçet's Disease and Healthy Subjects

The objective of this study was to investigate the elasticity characteristics of the optic nerve using strain and shear wave elastography in patients with Behçet's disease and to compare the results with those of healthy volunteers. Forty-six optic nerves from patients with Behçet's disease and 54 optic nerves from healthy volunteers were investigated prospectively in this study using strain and shear wave elastography. There was a statistically significant difference in terms of elasticity patterns between patients and healthy volunteers (p < 0.001). Elastographic images of healthy volunteers revealed most optic nerves to be type 3 (51.8%); however, type 2 (40.7%) and type 1 (7.5%) were also observed. Elastographic examination of Behçet's disease patients revealed type 2 in 52.2%, type 1 in 43.5% and type 3 in 4.3% of patients. Statistically significant differences were observed between patients and healthy volunteers in the analysis of shear wave elastography values (p < 0.001). Receiver operating characteristic curve analysis was perfect (0.933) (95% CI = 0.885-0.980), and a cutoff value of 16.5 kPa shear had very high sensitivity and specificity for the patient group. Strain and shear wave elastography findings for the optic nerves of patients with Behçet's disease were significantly different from those for healthy volunteers.

Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

OBJECTIVE

To measure the parapapillary atrophy (PPA) area in en face images obtained with swept-source optical coherence tomography (SS-OCT), and to evaluate its relationship to glaucoma, myopia, and age in non-highly myopic subjects.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Fifty eyes of 30 subjects with open-angle glaucoma (G group) and forty-three eyes of 26 healthy control subjects (C group). Eyes with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥ 26.5 mm) were excluded.

METHODS

Mean age ± standard deviation was 59.9 ± 12.4 years. The beta zone and the gamma zone PPA areas were measured in en face images reconstructed from three-dimensional SS-OCT images. Relationship between the PPA areas and patient characteristics such as glaucoma, axial length, and age was statistically evaluated using multivariate mixed-effects models.

MAIN OUTCOME MEASURES

Areas of the beta zone and the gamma zone PPA measured on en face OCT images.

RESULTS

Average ± standard deviation area of the beta and the gamma zone was 0.64 ± 0.79 and 0.16 ± 0.30 mm2, respectively. In multivariate models, the gamma zone significantly correlated with axial length (P = 0.001) but not with glaucoma (P = 0.944). In contrast, the beta zone significantly correlated with age (P = 0.0249) and glaucoma (P = 0.014).

CONCLUSIONS

En face images reconstructed from 3D SS-OCT data facilitated measurements of the beta and the gamma PPA zones even in eyes with optic disc distortion. The OCT-defined beta zone is associated with glaucoma and age, whereas the gamma zone correlated with myopia but not with glaucoma. This study confirmed the clinical usefulness of OCT-based classification of the PPA zones in distinguishing glaucomatous damage of the optic nerve from myopic damage in non-highly myopic eyes.

Glaucoma in high myopia and parapapillary delta zone

Purpose

To examine the prevalence of glaucomatous optic neuropathy (GON) in a medium myopic to highly myopic group of patients and its association with parapapillary gamma zone and parapapillary delta zone.

Methods

The retrospective observational hospital-based study included patients who had attended the Tokyo High Myopia Clinics within January 2012 and December 2012 and for whom fundus photographs were available. GON was defined based on the appearance of the optic nerve head on the fundus photographs.

Results

The study included 519 eyes (262 individuals) with a mean age of 62.0±14.3 years (range:13–89 years) and mean axial length of 29.5±2.2 mm (range:23.2–35.3mm). GON was present in 141 (27.2%; 95% confidence intervals (CI): 23.3, 31.0%) eyes. Prevalence of GON increased from 12.2% (1.7, 22.7) in eyes with an axial length of <26.5mm to 28.5% (24.4, 32.5) in eyes with an axial length of ≥26.5mm, to 32.6% (27.9, 37.2) in eyes with an axial length of ≥28mm, to 36.0% (30.5, 41.4) in eyes with an axial length of ≥29mm, and GON prevalence increased to 42.1% (35.5, 48.8) in eyes with an axial length of ≥30mm. In multivariate analysis, higher GON prevalence was associated (Nagelkerke r²: 0.28) with larger parapapillary delta zone diameter (P<0.001; odds ratio (OR):1.86;95%CI:1.33,2.61), longer axial length (P<0.001;OR:1.45;95%CI:1.26,1.67) and older age (P = 0.01;OR:1.03;95%CI:1.01,1.05). If parapapillary delta zone width was replaced by the vertical disc diameter, higher GON prevalence was associated (r²:0.24) with larger vertical optic disc diameter (P = 0.04;OR:1.70;95%CI:1.03,2.81), after adjusting for longer axial length (P<0.001;OR:1.44;95%CI:1.26,1.64) and older age (P<0.001;OR:1.04;95%CI:1.02,1.06).

Conclusions

Axial elongation associated increase in GON prevalence (mean: 28.1% in a medium to highly myopic study population) was associated with parapapillary delta zone as surrogate for an elongated peripapillary scleral flange and with larger optic disc size.

[Not Available]

Dynamics of the posttraumatic spasticity syndrome, a key component of spinal trauma, was investigated on simulation model of the open penetrating spinal cord (SC) trauma on adult male rats of aWistarline after half transection of the SC cross'section with its durable compression by biocompatible foreign body. Squeezing of the injured SC by foreign body potentiates formation of spasticity syndrome, and do not influence or restricts a severe pain syndrome occurrence. Reduction of the SC squeezing due to the foreign body elongation and reduction of its volume was accompanied by trustwor' thy rising of functional activity and the spasticity reduction in paretic extremity. Changes in activity of efferent chain of the movement system while formation of spasticity syn' drome in simulated trauma have occurred in both parts of SC ' in the injured one and in intact one as well, its severity did not correlate with presence of foreign body in zone of trauma.

PEHO Syndrome May Represent Phenotypic Expansion at the Severe End of the Early-Onset Encephalopathies

BACKGROUND

Progressive encephalopathy with edema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a distinct neurodevelopmental disorder. Patients without optic nerve atrophy and brain imaging abnormalities but fulfilling other PEHO criteria are often described as a PEHO-like syndrome. The molecular bases of both clinically defined conditions remain unknown in spite of the widespread application of genome analyses in both clinic and research.

METHODS

We enrolled two patients with a prior diagnosis of PEHO and two individuals with PEHO-like syndrome. All four individuals subsequently underwent whole-exome sequencing and comprehensive genomic analysis.

RESULTS

We identified disease-causing mutations in known genes associated with neurodevelopmental disorders including GNAO1 and CDKL5 in two of four individuals. One patient with PEHO syndrome and a de novoGNAO1 mutation was found to have an additional de novo mutation in HESX1 that is associated with optic atrophy.

CONCLUSIONS

We hypothesize that PEHO and PEHO-like syndrome may represent a severe end of the spectrum of the early-onset encephalopathies and, in some instances, its complex phenotype may result from an aggregated effect of mutations at two loci.

[STUDY EFFECT OF ASSOSIATED PATHOLOGY ON THE DEVELOPMENT OF OPTIC NERVE ATROPHY]

Studied effect of assosiated pathology on the development of optic nerve atrophy (ONA). The basis of population study was comparison some factors in the groups with ONA and without ONA (analysis case-control) and evaluation of relative risk. Analysis showed that the risk of development of ONA increased in coronary heart disease, hypertension, diabetes, atherosclerosis. A functional-organizational model of care for patients with ONA was proposed.

Optic Disc-Fovea Distance, Axial Length and Parapapillary Zones. The Beijing Eye Study 2011

Purpose

To measure the distance between the optic disc center and the fovea (DFD) and to assess its associations.

Methods

The population-based cross-sectional Beijing Eye Study 2011 included 3468 individuals aged 50+ years. The DFD was measured on fundus photographs.

Results

Readable fundus photographs were available for 2836 (81.8%) individuals. Mean DFD was 4.76 ± 0.34mm (median: 4.74 mm; range: 3.76–6.53mm). In multivariate analysis, longer DFD was associated with longer axial length (P<0.001; standardized correlation coefficient beta: 0.62), higher prevalence of axially high myopia (P<0.001; beta:0.06), shallower anterior chamber depth (P<0.001; beta:-0.18), thinner lens thickness (P = 0.004; beta: -0.06), smaller optic disc-fovea angle (P = 0.02; beta: -0.04), larger parapapillary alpha zone (P = 0.008; beta: 0.05), larger parapapillary beta/gamma zone (P<0.001; beta: 0.11), larger optic disc area (P<0.001; beta: 0.08), lower degree of cortical cataract (P = 0.002; beta: -0.08), and lower prevalence of age-related macular degeneration (P = 0.001; beta: -0.06). Bruch´s membrane opening-fovea distance (DFD minus disc radius minus parapapillary beta/gamma zone width) in non-glaucomatous eyes was not significantly (P = 0.60) related with axial length in emmetropic or axially myopic eyes (axial length ≥23.5 mm), while it increased significantly (P<0.001; r: 0.32) with longer axial length in eyes with an axial length of <23.5mm. Ratio of mean DFD to disc diameter was 2.65 ± 0.30. If the ratio of disc-fovea distance to disc diameter was considered constant and if the individual disc diameter was calculated as the individual disc-fovea distance divided by the constant factor of 2.65, the resulting calculated disc diameter differed from the directly measured disc diameter by 0.16 ±0.13 mm (median: 0.13 mm, range: 0.00–0.89 mm) or 8.9 ± 7.3% (median: 7.4%; range: 0.00–70%) of the measured disc diameter.

Conclusions

DFD (mean: 4.76mm) increases with longer axial length, larger parapapillary alpha zone and parapapillary beta/gamma zone, and larger disc area. The axial elongation associated increase in DFD was due to an enlargement of parapapillary beta/gamma zone while the Bruch’s membrane opening-fovea distance did not enlarge with longer axial length. This finding may be of interest for the process of emmetropization and myopization. Due to its variability, the disc-fovea distance has only limited clinical value as a relative size unit for structures at the posterior pole.

Optic Disc Change during Childhood Myopic Shift: Comparison between Eyes with an Enlarged Cup-To-Disc Ratio and Childhood Glaucoma Compared to Normal Myopic Eyes

BACKGROUND

Progressive disc tilting and the development or enlargement of peripapillary atrophy (PPA) are observed during a myopic shift in children. This could be related to the changes around the optic nerve head during eyeball elongation. If the biomechanical properties at or around the optic nerve head are changed after exposure to elevated intraocular pressure (IOP) in glaucoma eyes, different response of the disc tilting and PPA changes could take place during eyeball elongation by myopic shift. On the basis of this background, the aim of this study was to compare the morphological changes in the optic disc induced by a myopic shift during childhood between normal control eyes, eyes from disc suspects with an enlarged cup-to-disc ratio (CDR), and eyes with childhood glaucoma.

METHODS

Total of 82 eyes from 82 subjects younger than 14 years of age were included in the study. Serial disc photographs were classified into one of two groups: eyes with an optic nerve head (ONH) or peripapillary atrophy (PPA) change or without an ONH/PPA change. Using ImageJ software, the outlines of the optic disc and PPA were plotted, and the vertical disc diameter (VDD), horizontal disc diameter (HDD), and maximum PPA width (PPW) were measured. The changes in the ratios of these parameters and the relationships between the degree of myopic shift or the ONH/PPA change were analyzed.

RESULTS

Twenty-five eyes with normal optic disc appearance, 36 eyes with enlarged cup-to-disc ratio, and 21 eyes of glaucoma patients were analyzed. The initial intraocular pressure (IOP) at diagnosis was significantly different among the groups (P<0.001). The degree of myopic shift during follow-up period was not significantly different among the groups (P=0.612). However, the changes in the HDD/VDD and PPW/VDD ratios were significantly greater in the disc suspect group and significantly smaller in the glaucoma group. Among the 42 eyes with an ONH/PPA change, 16 (38.1%) were from the normal control group, 24 (57.1%) were from the disc suspect group, and 2 (4.8%) were from the glaucoma group (P < 0.001).

CONCLUSIONS AND RELEVANCE

The optic disc change during childhood myopic shift was different in eyes with various conditions. Eyes of childhood glaucoma showed less change in the disc morphology during myopic shift compared to eyes with normal disc or enlarged cup-to-disc ratio.

[Ocular ischemic syndrome--a case report]

Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started.

Peripapillary atrophy detection by sparse biologically inspired feature manifold

Peripapillary atrophy (PPA) is an atrophy of pre-existing retina tissue. Because of its association with eye diseases such as myopia and glaucoma, PPA is an important indicator for diagnosis of these diseases. Experienced ophthalmologists are able to determine the presence of PPA using visual information from the retinal images. However, it is tedious, time consuming and subjective to examine all images especially in a screening program. This paper presents biologically inspired feature (BIF) for the automatic detection of PPA. BIF mimics the process of cortex for visual perception. In the proposed method, a focal region is segmented from the retinal image and the BIF is extracted. As BIF is an intrinsically low dimensional feature embedded in a high dimensional space, it is not suitable to measure the similarity between two BIFs directly based on the Euclidean distance. Therefore, it is necessary to obtain a suitable mapping to reduce the dimensionality. In this paper, we explore sparse transfer learning to transfer the label information from ophthalmologists to the sample distribution knowledge contained in all samples. Selective pair-wise discriminant analysis is used to define two strategies of sparse transfer learning: negative and positive sparse transfer learning. Experimental results show that negative sparse transfer learning is superior to the positive one for this task. The proposed BIF based approach achieves an accuracy of more than 90% in detecting PPA, much better than previous methods. It can be used to save the workload of ophthalmologists and thus reduce the diagnosis costs.

Parapapillary atrophy: histological gamma zone and delta zone

Background

To examine histomorphometrically the parapapillary region in human eyes.

Methodology/Principal Findings

The histomorphometric study included 65 human globes (axial length:21–37 mm). On anterior-posterior histological sections, we measured the distance Bruch's membrane end (BME)-optic nerve margin (“Gamma zone”), BME-retinal pigment epithelium (RPE) (“Beta zone”), BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. “Delta zone” was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm) was significantly (P = 0.01) larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28) associated with axial length. Beta zone was significantly (P = 0.004) larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm) was associated with axial length (P<0.001;r² = 0.73) with an increase starting at an axial length of 26.5 mm. It was not significantly (P = 0.24) associated with glaucomatous optic neuropathy. Delta zone (present only in eyes with axial length of ≥27 mm) was associated with axial length (P = 0.001) and scleral flange length (P<0.001) but not with glaucoma (P = 0.73).

Conclusions/Significance

Parapapillary gamma zone (peripapillary sclera without overlying choroid, Bruch's membrane and deep retinal layers) was related with axial globe elongation and was independent of glaucoma. Delta zone (no blood vessels >50 µm diameter within gamma zone) was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch's membrane without RPE) was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.

A new phenotype of brain iron accumulation with dystonia, optic atrophy, and peripheral neuropathy

BACKGROUND

Neurodegeneration with brain iron accumulation is clinically and genetically heterogeneous because of mutations in at least 7 nuclear genes.

METHODS

We performed homozygosity mapping and whole-exome sequencing in 2 brothers with brain iron accumulation from a consanguineous family.

RESULTS

We identified a homozygous missense mutation in both brothers in the very recently identified chromosome 19 open-reading frame 12 gene. The disease presented before age 10 with slowly progressive tremor, dystonia, and spasticity. Additional features were optic atrophy, peripheral neuropathy, and learning difficulties. A raised serum creatine kinase indicated neuromuscular involvement, and compensatory mitochondrial proliferation implicated mitochondrial dysfunction as a pathological mechanism.

CONCLUSIONS

Further studies are needed to explore the function of the chromosome 19 open-reading frame 12 gene, and extended genetic analysis on larger patient cohorts will provide more information about the presentation and frequency of this disease.

Neurological disorders associated with cassava diet: a review of putative etiological mechanisms

Tropical ataxic neuropathy (TAN) and epidemic spastic paraparesis (konzo) are two neurological disorders associated with the consumption of cassava (Manihot esculenta) in several African countries. TAN is characterized by sensory polyneuropathy, sensory ataxia, bilateral optic atrophy and bilateral sensori-neural deafness. It occurs in elderly individuals subsisting on a monotonous cassava diet with minimal protein supplementation. Konzo is a syndrome of symmetrical spastic paraparesis with a predilection for children and young women and invariably associated with consumption of inadequately processed bitter cassava roots with minimal protein supplementation. Despite numerous epidemiological, clinical and biochemical studies aimed at elucidating the etiological mechanisms of these disorders, their etiologies remain unknown, and there is no known treatment. The diseases continue to be prevalent in endemic areas, causing significant disability and increased mortality. A fresh appraisal of the putative etiologic mechanisms proposed for these intriguing and enigmatic syndromes is presented in this paper. Evidences against a causal role for cyanide intoxication are discussed, and evidences implicating thiamine deficiency as a unifying etiological mechanism for these neurological syndromes are presented. It is concluded that urgent research is needed to evaluate thiamine status and implement a therapeutic trial of thiamine in these debilitating neurological disorders.

[The clinical study of the damage of visual function caused by pituitary tumor]

PURPOSE

To investigate the clinical manifestation of damage of visual function caused by pituitary adenoma.

METHODS

Visual acuity, visual field, fundus fluorescein angiography (FFA), pattern visual evoked potential (PVEP) and examination fundus were performed in 126 cases (252 eyes) of pituitary tumor.

RESULTS

There was 73.8% (186 eyes) of patients with decreased visual acuity, 51.6% (130 eyes) with primary optic atrophy, 69.6% (156 eyes) with the defects of visual field and 88.9% (160 eyes) with abnormal PVEP. Abnormal ophthalmological manifestation was the first diagnostic symptom in 26.2%, and 16.7% was misdiagnosed as eye diseases.

CONCLUSIONS

Pituitary tumor could cause defection of visual function. It is helpful to early diagnosis and timely treatment by fully understanding clinical features in the eye with pituitary tumor.

A boy with severe craniodiaphyseal dysplasia and apparently normal mother

We describe a boy and his mother affected with craniodiaphyseal dysplasia (CDD). The boy had a very severe form of the disease with extensive osteosclerosis already at birth. Facial diplegia, bilateral hearing loss and optic nerve atrophy were early, severe complications of the disease. At age 7 years progressive genu valgum and unusual epimetaphyseal radiographic appearances suggested hyperparathyroidism. This was confirmed by biochemical tests. Because of some facial similarity between the asymptomatic mother and the propositus, a limited skeletal survey of the mother was performed. It demonstrated cranial osteosclerosis and hyperostosis. It is possible that the mother has somatic mosaicism for a mutation of the genes causing CDD.

Rathke's cleft cyst--an uncommon cause of headache in a young boy

Developmental disorders of the pituitary can present like a mass lesion in the region of the pituitary and produce pressure effects. Rathke's cleft cyst is one such developmental disorder of the pituitary which presents in early life producing pressure effects namely visual disturbances due to its proximity to optic chiasma, headache, and hormonal imbalance due to pituitary malfunction. In this case report a 19 years boy presented with symptoms of headache and gradual loss of vision over one year period. Neuro-imaging study demonstrated a cystic lesion in the region of the pituitary. Trans-sphenoidal hypophysectomy was performed. Histopathology of the biopsied material was suggestive of Rathke's cleft cyst. Following surgery the boy had a good visual recovery. So early diagnosis and removal of a Rathke's cleft cyst has a good prognosis as compared to a craniopharyngioma which is a very close differential diagnosis.

Progressive atrophy in the optic pathway and visual cortex of early blind Chinese adults: A voxel-based morphometry magnetic resonance imaging study

Many previous neuroimaging studies have shown that the early visual cortex of the early blind (EB) exhibits significant functional plasticity. However, only few previous studies have addressed the question whether or not such functional plasticity is accompanied by, and even related to, structural plasticity. In this study, we acquired high-resolution whole-brain anatomical magnetic resonance images form 14 Chinese EB adults, who lost sight before 6 years of age, and 16 age/gender-matched normal-sighted controls (SC), and compared pixel-by-pixel the gray matter (GM) and white matter (WM) volumes between the two groups with voxel-based morphometry. The results showed that, relative to the SC, the EB exhibits significantly reduced WM volumes in the optic tract and optic radiation and significant GM losses in the early visual cortex. The reduction of WM volume in the optic radiation of the EB was found be modulated by both the age at blindness onset and the duration of blindness. The reduction of GM volume in the early visual cortex of the EB appeared to be unaffected by the age at blindness onset. However, it was found in localized regions of the atrophic early visual cortex of the EB that the GM loss was progressive with aging and increasing duration of blindness. These results suggest that early visual deprivation induces significant structural plasticity in the optic pathway and early visual cortex of the EB, which likely occurs during both the critical period of early neurodevelopment and the course of persisted blindness later in life through activity-dependent mechanisms.

Optic Nerve Imaging in Multiple Sclerosis

In this article I review the last 10 years of progress in the imaging of the optic nerve with a particular focus on applications to multiple sclerosis (MS). Development of magnetic resonance imaging (MRI) of the optic nerve has lagged behind imaging of other parts of the CNS. These limitations are due to technical challenges related to the small size and mobility of the optic nerves and artefacts caused by surrounding cerebrospinal fluid, orbital fat, and air-bone interfaces. Nonetheless the last 10 years has seen significant progress with regard to detecting optic nerve atrophy following optic neuritis, the use of fat- and CSF-suppressed high resolution imaging, the ability to measure magnetization transfer ratio and diffusivity in the optic nerve, and the emergence of SPIR-FLAIR for increasing sensitivity to inflammatory demyelination. Remaining challenges include further reduction of movement artifacts, testing ultra-high field MRI systems and dedicated surface coils, and developing automated segmentation techniques to improve the reproducibility of quantitative measurements. Finally the role of optic coherence tomography as a marker of retinal damage needs to be clarified further through correlations with MRI, clinical, and electrophysiologic data.

3D vs 2D qualitative and semiquantitative evaluation of the glaucomatous optic disc atrophy using computer-assisted stereophotography

BACKGROUND AND PURPOSE

Real colour documentation of the optic nerve head (ONH) is one of the most important methods to identify the early progression of glaucomatous optic nerve damage. This study compares the qualitative and semiquantitative evaluation of ONH photographs, using a 3D time-multiplexing system and conventional 2D photography, visualised on a computer monitor.

PATIENTS AND METHODS

Stereophotographs of the ONH were converted by special software in a 3D file. The same images were shown in 2D and 3D to 22 subjects with different training grades (residents and ophthalmologists). The evaluation based on a standardised questionnaire, containing semiquantitative parameters of the ONH. A weighted score for quality of ONH assessment counted the correct answers of the observers to compare their evaluation in 2D to the one made in 3D.

RESULTS

All of the observers achieved a significant better evaluation of the ONH with 3D than with 2D images. No significant differences were observed between both groups. Classification errors with respect to the 'gold standard' were lower for 3D measurements as compared with 2D measurements (P=0.007). No significant differences were observed between the gold standard and residents or ophthalmologists for the ONH size, but for the c/dratio the stereoscopic images lead to better results.

CONCLUSION

This study showed a better evaluation of parameters associated with the glaucomatous ONH atrophy with 3D images compared with 2D, independent of the clinical training grade. The computer-based evaluation of the ONH atrophy by using a time-multiplexing system (shutter-glasses) may improve the diagnosis of glaucoma patients.

Optic nerve hydropic axonal degeneration and blocked retrograde axoplasmic transport: histopathologic features in human high-pressure secondary glaucoma

OBJECTIVE

To describe histopathologic features of anterior optic nerves of 12 eyes enucleated for sustained high ocular pressure from iris-ciliary body melanomas in 10 and choroidal melanomas with chronic angle closure in 2.

METHODS

In this retrospective study, we analyzed cases indexed in 2 eye pathology laboratories and reviewed the pertinent literature. Cases were identified from diagnostic indexes; microscopic study of slides stained with hematoxylin-eosin and Verhoeff-van Gieson, Mallory trichrome, periodic acid-Schiff, alcian blue, or colloidal iron for acid mucopolysaccharide; review of available clinical documentation; and analysis of features and photography. The main outcome measures were description of optic nerve heads, prelaminar atrophy, laminar posterior bowing, locations and density of hydropic axonal degeneration, blocked retrograde axoplasmic transport, posterior atrophy, and optic nerve disorganization with glial proliferation.

RESULTS

Hydropic axonal degeneration was present in front of, within, and posterior to the lamina cribrosa in all 12 eyes. This degeneration extended diffusely and posteriorly from the peripheral lamina and was most dense centrally in 10 eyes. Retrolaminar changes compatible with blockage of retrograde axoplasmic transport were seen in 9 eyes. Posterior atrophy with disorganization and glial proliferation was seen in 10 eyes. No eye had classic glaucomatous atrophic cupping.

CONCLUSIONS

Diffuse and centrally intense hydropic axonal degeneration and central blocked retrograde axoplasmic transport explain loss of central acuity, generalized contraction of visual field, and generalized optic atrophy without glaucomatous cupping in eyes with prolonged high-pressure secondary glaucoma.

Optic atrophy after sildenafil use

BACKGROUND

It has been well-reported that phosphodiesterase-5 (PDE-5) inhibitors, originally investigated for their effect on smooth muscles and now used widely in treatment of erectile dysfunction, can cause mild transient visual disturbances because of their action on inhibiting enzymes involved in retinal transduction. Recently, these medications have been associated with the development of non-arteritic anterior ischemic optic neuropathy (NAAION) with attendant vision loss.

CASE REPORT

An older male patient, previously examined and ocularly healthy, presented asymptomatically with an occult optic neuropathy, not characteristic of NAAION. Neuroimaging and serology failed to reveal any other underlying cause. The patient did, however, report the use of sildenafil during the interval between his previously normal examination and the observation of his optic neuropathy.

CONCLUSIONS

This case details the development of an optic neuropathy with atrophy seemingly associated with the use of sildenafil, although no cause and effect could be conclusively found. This may indicate that medications used in the treatment of erectile dysfunction may be responsible for optic neuropathies other than NAAION.

Wolfram syndrome

Wolfram syndrome (WFS) is a rare diffuse neurodegenerative disorder characterized by diabetes insipidus, diabetes mellitus, optic atrophy, deafness, and a wide variety of central nervous system abnormalities. Insulin-dependent diabetes mellitus with optic nerve atrophy is sufficient criteria for the diagnosis. WFS is a devastating disease for the patients and their families. This study emphasizes the need for careful evaluation of cases having insulin-dependent diabetes mellitus and optic atrophy.

Optic atrophy due to Curvularia lunata mucocoele

The authors report on the case of a 57-year-old male who presented with poor vision of his right eye. He had right optic nerve atrophy secondary to neural compression by a mucocoele in the pituitary fossa. The patient underwent transphenoidal resection of the mucocoele. Microbiology revealed Curvularia lunata and Enterobacter aerogenes present in the specimen. He was treated with liposomal Amphotericin B and meropenem. Assessment of vision post-operatively demonstrated improvement in his visual acuity. On reviewing the published literature, this case was found to be the first in which Curvularia had caused optic neuropathy. There have been only five previously documented reports of Curvularia causing CNS infections. This case demonstrates the importance of obtaining a tissue diagnosis together with appropriate surgical and medical management in the treatment of invasive fungal disease.

Correlation between peripapillary atrophy and corticosteroid therapy in patients with Vogt-Koyanagi-Harada disease

AIMS

To determine the correlation between systemic corticosteroid therapy and the occurrence and size of peripapillary atrophy (PPA) in patients with Vogt-Koyanagi-Harada (VKH) disease.

METHODS

All patients with VKH disease were retrospectively reviewed for their corticosteroid regimen. The extent of the PPA, if present, was measured using digitized imaging software, by two masked observers. Eyes with myopia greater than 6 dioptres or glaucoma were excluded. The patients were classified into three groups: early high (EH), late high (LH), and low dose (LD), according to the dose and timing of corticosteroids received during the acute phase of the disease.

RESULTS

There were 40 eyes in the EH group, 25 eyes in the LH group, and 23 eyes in the LD group. Multivariate analysis showed that corticosteroid therapy was the main determinant of PPA occurrence. All the eyes in the LD group had PPA and eyes in the LH groups were 4.02 times (95% confidence interval 1.24-13.07) more likely to develop PPA than those in the EH group. The LD group also had larger PPA to disc ratios than the EH group. (Mean of 2.83 vs0.19, P<0.001).

CONCLUSION

The development and extent of PPA in patients with VKH disease appear to be dependent on the dose and timing of systemic corticosteroids.

Sarcomatoid carcinoma and orbital apex syndrome

PURPOSE

To report a case of sarcomatoid carcinoma and orbital apex syndrome in a previously healthy adult.

METHODS

A previously healthy 45-year-old man presented with exophthalmos of the left eye and a mass visible through his left nostril. A biopsy was performed and immunohistochemistry was used to confirm the diagnosis of the tumor. The patient was treated with chemotherapy and radiotherapy.

RESULTS

After treatment, we observed a substantial reduction in the size of the mass, but side effects of treatment developed. The visual acuity of the left eye was no light perception. Eight months later, the patient presented with bone and liver metastases, and he died 4 months later.

CONCLUSIONS

Sarcomatoid carcinoma is an aggressive tumor that can produce compressive symptoms with very poor visual and survival prognoses. A cranio-orbital computed tomography scan should be performed when patients present with symptoms of conjunctivitis and orbital apex syndrome.

Axonal neuropathy with optic atrophy is caused by mutations in mitofusin 2

OBJECTIVE

Charcot-Marie-Tooth (CMT) neuropathy with visual impairment due to optic atrophy has been designated as hereditary motor and sensory neuropathy type VI (HMSN VI). Reports of affected families have indicated autosomal dominant and recessive forms, but the genetic cause of this disease has remained elusive.

METHODS

Here, we describe six HMSN VI families with a subacute onset of optic atrophy and subsequent slow recovery of visual acuity in 60% of the patients. Detailed clinical and genetic studies were performed.

RESULTS

In each pedigree, we identified a unique mutation in the gene mitofusin 2 (MFN2). In three families, the MFN2 mutation occurred de novo; in two families the mutation was subsequently transmitted from father to son indicating autosomal dominant inheritance.

INTERPRETATION

MFN2 is a mitochondrial membrane protein that was recently reported to cause axonal CMT type 2A. It is intriguing that MFN2 shows functional overlap with optic atrophy 1 (OPA1), the protein underlying the most common form of autosomal dominant optic atrophy, and mitochondrial encoded oxidative phosphorylation components as seen in Leber's hereditary optic atrophy. We conclude that autosomal dominant HMSN VI is caused by mutations in MFN2, emphasizing the important role of mitochondrial function for both optic atrophies and peripheral neuropathies.

Novel mutations in the OPA1 gene and associated clinical features in Japanese patients with optic atrophy

PURPOSE

Autosomal dominant optic atrophy (ADOA) is characterized by symmetrical bilateral optic atrophy associated with reduced corrected visual acuity (VA), central or centrocecal scotoma, and color vision disturbances. The disease is genetically heterogeneous, and the OPA1 gene has been identified as the only causative gene. The aims of this study were to identify and report mutations in the OPA1 gene in Japanese patients with ADOA and to describe the clinical features associated with the mutations.

DESIGN

Molecular genetic study and observational case reports.

PARTICIPANTS

Nine unrelated Japanese families with optic atrophy and 8 isolated cases of optic atrophy.

METHODS

Genomic DNA was extracted from peripheral leukocytes, and all exons containing the open reading frame of the OPA1 gene and the flanking intron splice sites were sequenced directly. Complete ophthalmologic examinations were performed.

MAIN OUTCOME MEASURES

Direct sequencing of the OPA1 gene and clinical evaluations including VA, visual field, color vision, and disc appearance.

RESULTS

Ten different heterozygous mutations, including 6 novel mutations, were detected in the OPA1 gene. The identified mutations included 5 deletions/insertions (c.2061delA, c.2098_2103delCTTAAA, c.2538insT, c.2591insC, and c.2708_2711delTTAG), 4 nonsense mutations (c.112C>T [p.R38X], c.181C>T [p.Q61X], c.946A>T [p.R316X], and c.2713C>T [p.R905X]), and 1 missense mutation (c.1635C>A [p.S545R]). The most common mutation in Caucasians (c.2708_2711delTTAG) was found in 3 unrelated families, suggesting that it is a mutational hot spot. We detected an OPA1 mutation in 8 of 9 familial cases of optic atrophy and in 4 of 8 cases that were initially considered to be sporadic from the patients' family histories. Examinations of family members of 2 sporadic probands revealed the existence of other family members with the OPA1 mutations whose phenotype was very mild or within normal limits. This indicates that patients with ADOA sometimes seem to be sporadic because of the extensive variation in the phenotype or, alternatively, a low penetrance of ADOA.

CONCLUSIONS

OPA1 gene mutations are causative in most familial cases of ADOA in Japanese. Sporadic cases of optic atrophy frequently may be caused by OPA1 mutations in the Japanese population. Molecular genetic examinations are useful in determining the hereditary patterns in some cases of optic atrophy.

Optic disc morphometry with optical coherence tomography: comparison with planimetry of fundus photographs and influence of parapapillary atrophy and pigmentary conus

PURPOSE

Optical coherence tomography (OCT) is an established method for visualising macular pathology and for measuring the thickness of parapapillary retinal nerve fibre layer. The purpose of the present study was to compare OCT measurements of the optic disc with those obtained by planimetry of fundus photographs and to investigate whether OCT measurements are influenced by the amount of parapapillary atrophy or pigmentary conus at the disc margin.

MATERIALS AND METHODS

Eighty-two eyes of 41 randomly selected Asian-Indian subjects were included. The mean age was 44.2+/-14.3 years (mean+/-SD). All eyes underwent optic disc assessment by OCT (fast optical disc protocol) and digital 20 degree disc photos.. Planimetry of the discs were performed by outlining the disc and the cup. The amount of parapapillary atrophy (zone beta) was quantified as the number of clock-hours around the disc with adjacent parapapillary atrophy. The same procedure was performed to quantify the amount of pigmentary conus around the disc.

RESULTS

Mean+/-SD disc size and mean+/-SD cup size in OCT measurements (2.37+/-0.51, 1.29+/-0.55) were significantly smaller than in photographic planimetry (2.83+/-0.62, 1.56+/-0.5: P<0.001, P<0.001). Optic discs with parapapillary atrophy (P=0.2) in their relative difference of disc sizes between OCT and planimetry. Similarly, optic discs with pigmentary conus (n=12) and discs without pigmentary conus (n=70) did not differ significantly (P=0.65). The relative difference in disc size between the two measurement modalities did not correlate with the amount of parapapillary atrophy (r=-0.17, P=0.29) or with the amount of pigmentary conus (r=-0.04, P=0.9).

CONCLUSION

OCT analysis of the optic disc produces significantly smaller parameters, compared to the established method of optic disc planimetry. Neither presence, nor extent of parapapillary atrophy zone beta and pigmentary conus seems to produce a systematic error in measurements of disc size with the OCT.