Nutritional blindness from avoidant-restrictive food intake disorder - recommendations for the early diagnosis and multidisciplinary management of children at risk from restrictive eating

Avoidant-restrictive food intake disorder (ARFID) is an eating disorder characterised by limited consumption or the avoidance of certain foods, leading to the persistent failure to meet the individual's nutritional and/or energy needs. The disordered eating is not explained by the lack of available food or cultural beliefs. ARFID is often associated with a heightened sensitivity to the sensory features of different types of food and may be more prevalent among children with autism spectrum disorder (ASD) for this reason. Sight loss from malnutrition is one of the most devastating and life-changing complications of ARFID, but difficult to diagnose in young children and those with ASD who have more difficulty with communicating their visual problems to carers and clinicians, leading to delayed treatment and greater probability of irreversible vision loss. In this article, we highlight the importance of diet and nutrition to vision and the diagnostic and therapeutic challenges that clinicians and families may face in looking after children with ARFID who are at risk of sight loss. We recommend a scaled multidisciplinary approach to the early identification, investigation, referral and management of children at risk of nutritional blindness from ARFID.

Heparanase inhibition as a systemic approach to protect the endothelial glycocalyx and prevent microvascular complications in diabetes

BACKGROUND

Diabetes mellitus is a chronic disease which is detrimental to cardiovascular health, often leading to secondary microvascular complications, with huge global health implications. Therapeutic interventions that can be applied to multiple vascular beds are urgently needed. Diabetic retinopathy (DR) and diabetic kidney disease (DKD) are characterised by early microvascular permeability changes which, if left untreated, lead to visual impairment and renal failure, respectively. The heparan sulphate cleaving enzyme, heparanase, has previously been shown to contribute to diabetic microvascular complications, but the common underlying mechanism which results in microvascular dysfunction in conditions such as DR and DKD has not been determined.

METHODS

In this study, two mouse models of heparan sulphate depletion (enzymatic removal and genetic ablation by endothelial specific Exotosin-1 knock down) were utilized to investigate the impact of endothelial cell surface (i.e., endothelial glycocalyx) heparan sulphate loss on microvascular barrier function. Endothelial glycocalyx changes were measured using fluorescence microscopy or transmission electron microscopy. To measure the impact on barrier function, we used sodium fluorescein angiography in the eye and a glomerular albumin permeability assay in the kidney. A type 2 diabetic (T2D, db/db) mouse model was used to determine the therapeutic potential of preventing heparan sulphate damage using treatment with a novel heparanase inhibitor, OVZ/HS-1638. Endothelial glycocalyx changes were measured as above, and microvascular barrier function assessed by albumin extravasation in the eye and a glomerular permeability assay in the kidney.

RESULTS

In both models of heparan sulphate depletion, endothelial glycocalyx depth was reduced and retinal solute flux and glomerular albumin permeability was increased. T2D mice treated with OVZ/HS-1638 had improved endothelial glycocalyx measurements compared to vehicle treated T2D mice and were simultaneously protected from microvascular permeability changes associated with DR and DKD.

CONCLUSION

We demonstrate that endothelial glycocalyx heparan sulphate plays a common mechanistic role in microvascular barrier function in the eye and kidney. Protecting the endothelial glycocalyx damage in diabetes, using the novel heparanase inhibitor OVZ/HS-1638, effectively prevents microvascular permeability changes associated with DR and DKD, demonstrating a novel systemic approach to address diabetic microvascular complications.

Time Spent Outdoors Partly Accounts for the Effect of Education on Myopia

Purpose

The purpose of this study was to investigate if education contributes to the risk of myopia because educational activities typically occur indoors or because of other factors, such as prolonged near viewing.

Methods

This was a two-sample Mendelian randomization study. Participants were from the UK Biobank, Avon Longitudinal Study of Parents and Children, and Generation R. Genetic variants associated with years spent in education or time spent outdoors were used as instrumental variables. The main outcome measures were: (1) spherical equivalent refractive error attained by adulthood, and (2) risk of an early age-of-onset of spectacle wear (EAOSW), defined as an age-of-onset of 15 years or below.

Results

Time spent outdoors was found to have a small genetic component (heritability 9.8%) that tracked from childhood to adulthood. A polygenic score for time outdoors was associated with children's time outdoors; a polygenic score for years spent in education was inversely associated with children's time outdoors. Accounting for the relationship between time spent outdoors and myopia in a multivariable Mendelian randomization analysis reduced the size of the causal effect of more years in education on myopia to -0.17 diopters (D) per additional year of formal education (95% confidence interval [CI] = -0.32 to -0.01) compared with the estimate from a univariable Mendelian randomization analysis of -0.27 D per year (95% CI = -0.41 to -0.13). Comparable results were obtained for the outcome EAOSW.

Conclusions

Accounting for the effects of time outdoors reduced the estimated causal effect of education on myopia by 40%. These results suggest about half of the relationship between education and myopia may be mediated by children not being outdoors during schooling.

Minimal reporting guideline for research involving eye tracking (2023 edition)

A guideline is proposed that comprises the minimum items to be reported in research studies involving an eye tracker and human or non-human primate participant(s). This guideline was developed over a 3-year period using a consensus-based process via an open invitation to the international eye tracking community. This guideline will be reviewed at maximum intervals of 4 years.

Cohort profile: rationale and methods of UK Biobank repeat imaging study eye measures to study dementia

PURPOSE

The retina provides biomarkers of neuronal and vascular health that offer promising insights into cognitive ageing, mild cognitive impairment and dementia. This article described the rationale and methodology of eye and vision assessments with the aim of supporting the study of dementia in the UK Biobank Repeat Imaging study.

PARTICIPANTS

UK Biobank is a large-scale, multicentre, prospective cohort containing in-depth genetic, lifestyle, environmental and health information from half a million participants aged 40-69 enrolled in 2006-2010 across the UK. A subset (up to 60 000 participants) of the cohort will be invited to the UK Biobank Repeat Imaging Study to collect repeated brain, cardiac and abdominal MRI scans, whole-body dual-energy X-ray absorptiometry, carotid ultrasound, as well as retinal optical coherence tomography (OCT) and colour fundus photographs.

FINDINGS TO DATE

UK Biobank has helped make significant advances in understanding risk factors for many common diseases, including for dementia and cognitive decline. Ophthalmic genetic and epidemiology studies have also benefited from the unparalleled combination of very large numbers of participants, deep phenotyping and longitudinal follow-up of the cohort, with comprehensive health data linkage to disease outcomes. In addition, we have used UK Biobank data to describe the relationship between retinal structures, cognitive function and brain MRI-derived phenotypes.

FUTURE PLANS

The collection of eye-related data (eg, OCT), as part of the UK Biobank Repeat Imaging study, will take place in 2022-2028. The depth and breadth and longitudinal nature of this dataset, coupled with its open-access policy, will create a major new resource for dementia diagnostic discovery and to better understand its association with comorbid diseases. In addition, the broad and diverse data available in this study will support research into ophthalmic diseases and various other health outcomes beyond dementia.

Effect of delivery mode on objective and subjective aspects of voice

OBJECTIVE

This study aimed to compare the effect of delivery on both objective and subjective parameters of voice.

PATIENTS AND METHODS

This is a prospective parallel-group randomized controlled trial. 105 women grouped in two; vaginal delivery (NG) and cesarean group (CG). The fundamental frequency (F0), jitter, shimmer, noise-to-harmonics ratio (NHR), number of voice breaks (VBn) and percentage of voice breaks (VB%) were determined in acoustic analysis. Voice Handicap Index 30 (VHI) was used for subjective analysis.

RESULTS

In NG, a significant decrease in jit%, shim% and VB% was observed (p <.05). In CG, all parameters including F0 showed a significant decrease in early postpartum period (p <.05). CG had more significant improvement in F 0, jit%, shim%, shimdB, VB%, VBn according to test statistics values. VHI scores increased in both NG and CG.

CONCLUSIONS

The change of objective parameters was more significant in CG. Vaginal delivery may cause vocal trauma which results in deterioration in objective acoustic measures as well as decrease in subjective voice quality.

Hyperopia Is Not Causally Associated With a Major Deficit in Educational Attainment

Purpose

Hyperopia (farsightedness) has been associated with a deficit in children's educational attainment in some studies. We aimed to investigate the causality of the relationship between refractive error and educational attainment.

Methods

Mendelian randomization (MR) analysis in 74,463 UK Biobank participants was used to estimate the causal effect of refractive error on years spent in full-time education, which was taken as a measure of educational attainment. A polygenic score for refractive error derived from 129 genetic variants was used as the instrumental variable. Both linear and nonlinear (allowing for a nonlinear relationship between refractive error and educational attainment) MR analyses were performed.

Results

Assuming a linear relationship between refractive error and educational attainment, the causal effect of refractive error on years spent in full-time education was estimated as -0.01 yr/D (95% confidence interval, -0.04 to +0.02; P = 0.52), suggesting minimal evidence for a non-zero causal effect. Nonlinear MR supported the hypothesis of the nonlinearity of the relationship (I2 = 80.3%; Cochran's Q = 28.2; P = 8.8e-05) but did not suggest that hyperopia was associated with a major deficit in years spent in education.

Conclusions

This work suggested that the causal relationship between refractive error and educational attainment was nonlinear but found no evidence that moderate hyperopia caused a major deficit in educational attainment. Importantly, however, because statistical power was limited and some participants with moderate hyperopia would have worn spectacles as children, modest adverse effects may have gone undetected.

Translational Relevance

These findings suggest that moderate hyperopia does not cause a major deficit in educational attainment.

Correction: Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images

[This corrects the article DOI: 10.1371/journal.pgen.1009497.].

134 Quantitative Assessment of Visual Function for Pituitary Macroadenomas: A Practical Scoring Algorithm

Introduction

There is a myriad of existing terms by which visual capacity is recorded. The lack of a standardised categorisation of observations commonly results in ambiguities. We report the utility of a visual function score (VFS) in patients managed by transsphenoidal surgery.

Method

A VFS (expressed as a percentage) with a maximum score of 20 was calculated for each eye using the Snellen VA (40% weighting: score 0-8) and Humphrey Allergan 30-2 automated visual field (60% weighting: score 0-12).

Results

280 patients (560 eyes) underwent transsphenoidal pituitary adenoma resections with complete pre- and post-operative visual function assessment. Mean age 56 years; 56.4% male. 26.1% were treated by endoscopic technique and 73.9% were treated by microscopic technique. Pre-operative vision was normal in 38.0% eyes. All these had full post-operative vision. In patients with pre-operative visual loss (347 eyes), the mean pre-operative VFS rose from 70.8% to 87.5% post-operatively. 43.8% eyes attained full post-operative vision, 28% improved, and 25.6% remained unchanged. 9 patients (2.6%) had worse immediate post-operative vision.

Conclusions

The VFS is a convenient single measure of visual function that may facilitate local and national audit of transsphenoidal surgery. Studies are planned to correlate this with patient reported visual quality of life measures.

Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images

Optical Coherence Tomography (OCT) enables non-invasive imaging of the retina and is used to diagnose and manage ophthalmic diseases including glaucoma. We present the first large-scale genome-wide association study of inner retinal morphology using phenotypes derived from OCT images of 31,434 UK Biobank participants. We identify 46 loci associated with thickness of the retinal nerve fibre layer or ganglion cell inner plexiform layer. Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. We extracted overall retinal thickness at the fovea, representative of foveal hypoplasia, with which three of the 46 SNPs were associated. We additionally associate these three loci with visual acuity. In contrast to the Mendelian causes of severe foveal hypoplasia, our results suggest a spectrum of foveal hypoplasia, in part genetically determined, with consequences on visual function.

P99 Quantitative Assessment of Visual Function for Pituitary Macroadenomas: A Practical Scoring Algorithm

Background

There is a myriad of existing terms by which visual capacity is recorded. The lack of a standardised categorisation of observations commonly result in ambiguities. We report the utility of a visual function score (VFS) in patients managed by transsphenoidal surgery.

Methods

A VFS (expressed as a percentage) with a maximum score of 20 was calculated for each eye using the Snellen VA (40% weighting: score 0-8) and Humphrey Allergan 30-2 automated visual field (60% weighting: score 0-12).

Results

280 patients (560 eyes) underwent transsphenoidal pituitary adenoma resections with complete pre and post-operative visual function assessment. Mean age 56 years; 56.4% male. 26.1% were treated by endoscopic technique and 73.9% by microscopic technique. Pre-operative vision was normal in 38.0% eyes and had full post-operative vision. In patients with pre-operative visual loss, the mean pre-operative VFS rose from 70.8% to 87.5% post-operatively. 43.8% eyes attained full post-operative vision, 28% improved, and 25.6% remained unchanged. 9 patients (2.6%) had worse immediate post-operative vision.

Discussion

The VFS is a convenient single measure of visual function that may facilitate local and national audit of transsphenoidal surgery. Studies are planned to correlate this with patient reported visual quality of life measures

Effect of Education on Myopia: Evidence from the United Kingdom ROSLA 1972 Reform

Purpose

Cross-sectional and longitudinal studies have consistently reported an association between education and myopia. However, conventional observational studies are at risk of bias due to confounding by factors such as socioeconomic position and parental educational attainment. The current study aimed to estimate the causal effect of education on refractive error using regression discontinuity analysis.

Methods

Regression discontinuity analysis was applied to assess the influence on refractive error of the raising of the school leaving age (ROSLA) from 15 to 16 years introduced in England and Wales in 1972. For comparison, a conventional ordinary least squares (OLS) analysis was performed. The analysis sample comprised 21,548 UK Biobank participants born in a nine-year interval centered on September 1957, the date of birth of those first affected by ROSLA.

Results

In OLS analysis, the ROSLA 1972 reform was associated with a -0.29 D (95% confidence interval [CI]: -0.36 to -0.21, P < 0.001) more negative refractive error. In other words, the refractive error of the study sample became more negative by -0.29 D during the transition from a minimum school leaving age of 15 to 16 years of age. Regression discontinuity analysis estimated the causal effect of the ROSLA 1972 reform on refractive error as -0.77 D (95% CI: -1.53 to -0.02, P = 0.04).

Conclusions

Additional compulsory schooling due to the ROSLA 1972 reform was associated with a more negative refractive error, providing additional support for a causal relationship between education and myopia.

Relationships between retinal layer thickness and brain volumes in the UK Biobank cohort

Background and purpose

Current methods to diagnose neurodegenerative diseases are costly and invasive. Retinal neuroanatomy may be a biomarker for more neurodegenerative processes and can be quantified in vivo using optical coherence tomography (OCT), which is inexpensive and noninvasive. We examined the association of neuroretinal morphology with brain MRI image‐derived phenotypes (IDPs) in a large cohort of healthy older people.

Methods

UK Biobank participants aged 40 to 69 years old underwent comprehensive examinations including ophthalmic and brain imaging assessments. Macular retinal nerve fibre layer (mRNFL), macular ganglion cell‐inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC) and total macular thicknesses were obtained from OCT. Magnetic resonance imaging (MRI) IDPs assessed included total brain, grey matter, white matter and hippocampal volume. Multivariable linear regression models were used to evaluate associations between retinal layers thickness and brain MRI IDPs, adjusting for demographic factors and vascular risk factors.

Results

A total of 2131 participants (mean age 55 years; 51% women) with both gradable OCT images and brain imaging assessments were included. In multivariable regression analysis, thinner mGCIPL, mGCC and total macular thickness were all significantly associated with smaller total brain (p < 0.001), grey matter and white matter volume (p < 0.01), and grey matter volume in the occipital pole (p < 0.05). Thinner mGCC and total macular thicknesses were associated with smaller hippocampal volume (p < 0.02). No association was found between mRNFL and the MRI IDPs.

Conclusions

Markers of retinal neurodegeneration are associated with smaller brain volumes. Our findings suggest that retinal structure may be a biomarker providing information about important brain structure in healthy older adults.

Intermediate uveitis associated with MS: Diagnosis, clinical features, pathogenic mechanisms, and recommendations for management

Uveitis is a major cause of visual impairment and blindness among working-age adults, accounting for 10% of legal blindness in the United States. Among people with MS, the prevalence of uveitis is 10 times higher than among the general population, and because MS and uveitis share similar genetic risk factors and immunologic effector pathways, it is not clear whether uveitis is one of the manifestations of MS or a coincident disorder. This uncertainty raises several diagnostic and management issues for clinicians who look after these patients, particularly with regard to recognizing visual symptoms resulting from demyelination, intraocular inflammation, or the visual complications of disease modifying drugs for MS, e.g., fingolimod. Likewise, management decisions regarding patients with uveitis are influenced by the risk of precipitating or exacerbating episodes of demyelination, e.g., following anti-tumor necrosis factor biologic therapy, and other neurologic complications of immunosuppressive treatments for uveitis. In this review, we explore the similarities in the pathophysiology, clinical features, and treatment of patients with uveitis and MS. Based on the latest evidence, we make a set of recommendations to help guide neurologists and ophthalmologists to best manage patients affected by both conditions.

A commonly occurring genetic variant within the NPLOC4-TSPAN10-PDE6G gene cluster is associated with the risk of strabismus

Strabismus refers to an abnormal alignment of the eyes leading to the loss of central binocular vision. Concomitant strabismus occurs when the angle of deviation is constant in all positions of gaze and often manifests in early childhood when it is considered to be a neurodevelopmental disorder of the visual system. As such, it is inherited as a complex genetic trait, affecting 2-4% of the population. A genome-wide association study (GWAS) for self-reported strabismus (1345 cases and 65,349 controls from UK Biobank) revealed a single genome-wide significant locus on chromosome 17q25. Approximately 20 variants across the NPLOC4-TSPAN10-PDE6G gene cluster and in almost perfect linkage disequilibrium (LD) were most strongly associated (lead variant: rs75078292, OR = 1.26, p = 2.24E-08). A recessive model provided a better fit to the data than an additive model. Association with strabismus was independent of refractive error, and the degree of association with strabismus was minimally attenuated after adjustment for amblyopia. The association with strabismus was replicated in an independent cohort of clinician-diagnosed children aged 7 years old (116 cases and 5084 controls; OR = 1.85, p = 0.009). The associated variants included 2 strong candidate causal variants predicted to have functional effects: rs6420484, which substitutes tyrosine for a conserved cysteine (C177Y) in the TSPAN10 gene, and a 4-bp deletion variant, rs397693108, predicted to cause a frameshift in TSPAN10. The population-attributable risk for the locus was approximately 8.4%, indicating an important role in conferring susceptibility to strabismus.

Education and myopia: assessing the direction of causality by mendelian randomisation

OBJECTIVES

To determine whether more years spent in education is a causal risk factor for myopia, or whether myopia is a causal risk factor for more years in education.

DESIGN

Bidirectional, two sample mendelian randomisation study.

SETTING

Publically available genetic data from two consortiums applied to a large, independent population cohort. Genetic variants used as proxies for myopia and years of education were derived from two large genome wide association studies: 23andMe and Social Science Genetic Association Consortium (SSGAC), respectively.

PARTICIPANTS

67 798 men and women from England, Scotland, and Wales in the UK Biobank cohort with available information for years of completed education and refractive error.

MAIN OUTCOME MEASURES

Mendelian randomisation analyses were performed in two directions: the first exposure was the genetic predisposition to myopia, measured with 44 genetic variants strongly associated with myopia in 23andMe, and the outcome was years in education; and the second exposure was the genetic predisposition to higher levels of education, measured with 69 genetic variants from SSGAC, and the outcome was refractive error.

RESULTS

Conventional regression analyses of the observational data suggested that every additional year of education was associated with a more myopic refractive error of -0.18 dioptres/y (95% confidence interval -0.19 to -0.17; P<2e-16). Mendelian randomisation analyses suggested the true causal effect was even stronger: -0.27 dioptres/y (-0.37 to -0.17; P=4e-8). By contrast, there was little evidence to suggest myopia affected education (years in education per dioptre of refractive error -0.008 y/dioptre, 95% confidence interval -0.041 to 0.025, P=0.6). Thus, the cumulative effect of more years in education on refractive error means that a university graduate from the United Kingdom with 17 years of education would, on average, be at least -1 dioptre more myopic than someone who left school at age 16 (with 12 years of education). Myopia of this magnitude would be sufficient to necessitate the use of glasses for driving. Sensitivity analyses showed minimal evidence for genetic confounding that could have biased the causal effect estimates.

CONCLUSIONS

This study shows that exposure to more years in education contributes to the rising prevalence of myopia. Increasing the length of time spent in education may inadvertently increase the prevalence of myopia and potential future visual disability.

A comparative analysis of rod bipolar cell transcriptomes identifies novel genes implicated in night vision

In the mammalian retina, rods and a specialised rod-driven signalling pathway mediate visual responses under scotopic (dim light) conditions. As rods primarily signal to rod bipolar cells (RBCs) under scoptic conditions, disorders that affect rod or RBC function are often associated with impaired night vision. To identify novel genes expressed by RBCs and, therefore, likely to be involved in night vision, we took advantage of the adult Bhlhe23^−/− mouse retina (that lacks RBCs) to derive the RBC transcriptome. We found that genes expressed by adult RBCs are mainly involved in synaptic structure and signalling, whereas genes that influence RBC development are also involved in the cell cycle and transcription/translation. By comparing our data with other published retinal and bipolar cell transcriptomes (where we identify RBCs by the presence of Prkca and/or Pcp2 transcripts), we have derived a consensus for the adult RBC transcriptome. These findings ought to facilitate further research into physiological mechanisms underlying mammalian night vision as well as proposing candidate genes for patients with inherited causes of night blindness.

New insights into the genetic component of non-infectious uveitis through an Immunochip strategy

BACKGROUND

Large-scale genetic studies have reported several loci associated with specific disorders involving uveitis. Our aim was to identify genetic risk factors that might predispose to uveitis per se, independent of the clinical diagnosis, by performing a dense genotyping of immune-related loci.

METHODS

613 cases and 3693 unaffected controls from three European case/control sets were genotyped using the Immunochip array. Only patients with non-infectious non-anterior uveitis and without systemic features were selected. To perform a more comprehensive analysis of the human leucocyte antigen (HLA) region, SNPs, classical alleles and polymorphic amino acid variants were obtained via imputation. A meta-analysis combining the three case/control sets was conducted by the inverse variance method.

RESULTS

The highest peak belonged to the HLA region. A more detailed analysis of this signal evidenced a strong association between the classical allele HLA-A*2902 and birdshot chorioretinopathy (p=3.21E-35, OR=50.95). An omnibus test yielded HLA-A 62 and 63 as relevant amino acid positions for this disease. In patients with intermediate and posterior uveitis, the strongest associations belonged to the rs7197 polymorphism, within HLA-DRA (p=2.07E-11, OR=1.99), and the HLA-DR15 haplotype (DRB1*1501: p=1.16E-10, OR=2.08; DQA1*0102: p=4.37E-09, OR=1.77; DQB1*0602: p=7.26E-10, OR=2.02). Outside the HLA region, the MAP4K4/IL1R2 locus reached statistical significance (rs7608679: p=8.38E-07, OR=1.42). Suggestive associations were found at five other loci.

CONCLUSIONS

We have further interrogated the association between the HLA region and non-infectious non-anterior uveitis. In addition, we have identified a new non-HLA susceptibility factor and proposed additional risk loci with putative roles in this complex condition.

Tumor necrosis factor polymorphisms associated with tumor necrosis factor production influence the risk of idiopathic intermediate uveitis

PURPOSE

Idiopathic intermediate uveitis (IIU) is a potentially sight-threatening inflammatory disorder with well-defined anatomic diagnostic criteria. It is often associated with multiple sclerosis, and both conditions are linked to HLA-DRB1*15. Previously, we have shown that non-infectious uveitis (NIU) is associated with interleukin 10 (IL10) polymorphisms, IL10-2849A (rs6703630), IL10+434T (rs2222202), and IL10+504G (rs3024490), while a LTA+252AA/TNFA-238GG haplotype (rs909253/rs361525) is protective. In this study, we determined whether patients with IIU have a similar genetic profile as patients with NIU or multiple sclerosis.

METHODS

Twelve polymorphisms were genotyped, spanning the tumor necrosis factor (TNF) and IL10 genomic regions, in 44 patients with IIU and 92 population controls from the UK and the Republic of Ireland.

RESULTS

IIU was strongly associated with the TNFA-308A and TNFA-238A polymorphisms. We found the combination of TNFA-308 and -238 loci was more strongly associated with IIU than any other loci across the major histocompatibility complex, including HLA-DRB1.

CONCLUSIONS

TNF polymorphisms, associated with increased TNF production, are highly associated with IIU. These results offer the potential to ascribe therapeutic response and risk (i.e., the influence of HLA-DRB1*15 status and TNFR1 polymorphism) to anti-TNF therapy in IIU.

Joubert syndrome presenting with motor delay and oculomotor apraxia

We describe two sisters who presented in early childhood with motor delay and unusual eye movements. Both demonstrated hypotonia and poor visual attention. The older girl at 14 weeks of age showed fine pendular horizontal nystagmus more pronounced on lateral gaze, but despite investigation with cranial MRI no diagnosis was reached. The birth of her younger sister four years later with a similar presentation triggered review of the sisters' visual behaviour. Each had developed an unusual but similar form of oculomotor apraxia (OMA) with head thrusts to maintain fixation rather than to change fixation. MRI of the older sibling demonstrated the characteristic "molar tooth sign" (MTS) of Joubert syndrome which was subsequently confirmed on MRI in the younger sibling. We discuss the genetically heterogeneous ciliopathies now grouped as Joubert syndrome and Related Disorders. Clinicians need to consider this group of disorders when faced with unusual eye movements in the developmentally delayed child.

Punctate inner choroidopathy and multifocal choroiditis with panuveitis share haplotypic associations with IL10 and TNF loci

PURPOSE

The white-dot syndromes are a heterogenous group of chorioretinal disorders that have many common clinical features. Whether these disorders represent distinct clinical entities or different manifestations of the same disease warrants further interrogation. Two white-dot syndromes were investigated, with closely overlapping phenotypes--multifocal choroiditis with panuveitis (MFCPU) and punctate inner choroidopathy (PIC)--for differences in clinical course and genotype frequency at IL10 and TNF loci, known to be associated with noninfectious uveitis.

METHODS

Twelve polymorphisms were genotyped, spanning the TNFA and IL10 genomic regions, in 61 patients with MFCPU or PIC and 92 population controls from the United Kingdom and Republic of Ireland.

RESULTS

There were clear differences in clinical course between patients with MFCPU and PIC which had prognostic significance. However, both patient groups demonstrated similar associations with the IL10 haplotype, IL10htSNP2(-2849)AX/htSNP5(+434)TC and negative associations with the TNF haplotype, LTA+252A/TNFhtSNP1(-308)G/TNFhtSNP2(-238)G/TNFhtSNP3(+488)A/TNFd3.

CONCLUSIONS

Despite clear differences in clinical course and outcome, MFCPU and PIC may still represent two manifestations of the same disease, given their similar genetic associations with IL10 and TNF loci, which are known to be associated with noninfectious uveitis and autoimmunity, in general. Definitive proof will necessitate genomewide sequence analysis. However, the data also support the notion that epigenetic factors have a strong effect on clinical phenotype.

Cytokine polymorphism in noninfectious uveitis

PURPOSE

Noninfectious uveitis is a sight-threatening immune-mediated intraocular inflammatory disorder. The inheritance of uveitis in multiplex families and its association with known monogenic and polygenic immunologic disorders suggests that common genetic variants underlie susceptibility to uveitis as well as to other immunologic disorders. TNFA and IL10 are strong candidate genes, given the influence of these cytokines on inflammation, immune tolerance, and apoptosis.

METHODS

The role of 12 polymorphisms spanning the TNFA and IL10 genomic regions was investigated in 192 uveitis patients and 92 population control subjects from four regional centers in the United Kingdom and Republic of Ireland.

RESULTS

The results demonstrate that uveitis is associated with three haplotype-tagging SNPs (htSNPs) in the IL10 gene: htSNP2 (rs6703630), htSNP5 (rs2222202), and htSNP6 (rs3024490). IL10htSNP2AG/htSNP5TC was the most significantly associated haplotype (P = 0.00085), whereas the LTA+252AA/TNFhtSNP2GG haplotype was protective (P = 0.00031). Furthermore, subgroup analysis showed that the frequency of the TNFd4 allele was higher in patients with nonremitting ocular disease and/or those requiring higher levels of maintenance immunosuppression. Although these associations lost significance after Bonferroni correction, they infer a relationship that may be validated by a larger study.

CONCLUSIONS

Since these variants are implicated in the susceptibility and severity of several immunologic disorders, the results support the hypothesis that common genetic determinants influence shared mechanisms of autoimmunity.

VEGF polymorphisms are associated with neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the most common cause of blindness in the elderly. Linkage has been shown to the vascular endothelial growth factor (VEGF) gene and ocular levels of VEGF are raised in individuals with the neovascular form of disease. To examine the role of VEGF further, we conducted a case-control study where 45 individuals with neovascular AMD and 94 age-matched controls were genotyped for 14 single nucleotide polymorphisms (SNPs) in the VEGF promoter and gene. The single SNP +674 CC genotype was significantly associated with AMD (OR=2.40, 95%CI 1.09-5.26, P=0.027). Haplotype analysis of SNPs +674, +4618, +5092, +9162 and +9512 revealed that CTCCT and TCACC were associated with AMD (OR=15.77, 95% CI 1.91-130.24, P=0.0161 and OR=9.95, 95%CI 3.22-30.74, P=0.000053, respectively). The haplotype TCACT was associated with the control group (P=0.0001832). Furthermore, haplotype analysis of promoter SNPs revealed that possession of the -460T, -417T, -172C, -165C, -160C, -152G, -141A, -116A, +405C haplotype was strongly associated with AMD (OR=18.24, 95%CI 2.25-148.25, P=0.0074). This is the most extensive analysis of the VEGF gene in AMD, demonstrating a clear association with the exudative form of disease, thereby creating the possibility for predictive testing. Smoking, high fat intake and hypertension are negative environmental risk factors in AMD, whereas increased consumption of dietary antioxidants can have a protective effect. Identification of those at risk in the population would allow individual counselling with lifestyle advice to reduce the risks of blindness. (Genbank accession nos M63971 and AF437895).

Cytokine gene polymorphism in sympathetic ophthalmia

PURPOSE

Sympathetic ophthalmia (SO) is a prototypical autoimmune disease in which injury to one eye causes sight-threatening inflammation in the otherwise normal contralateral eye. Previous work found that human leukocyte antigen alleles HLA-DRB1*04 and DQA1*03 are markers of increased susceptibility and severity in British and Irish patients. Evidence is accumulating that single nucleotide polymorphisms (SNPs) in cytokine genes can also influence the development of autoimmune disease through their effect on levels of cytokine production. The purpose of this study was to determine whether polymorphisms in the cytokine genes are important markers for disease severity and outcome in patients with SO.

METHODS

Twenty-six British and Irish patients meeting well-defined criteria for the diagnosis of SO were compared with 48 matched controls. Genotyping of SNPs in the TNFalpha, TNFbeta, and IL-10 genes was performed using the polymerase chain reaction and sequence-specific primers (SSP-PCRs) and of the CTLA-4 and TNF receptor 2 genes using restriction length polymorphism-PCR (RFLP-PCR).

RESULTS

Significant associations were found between the IL-10 -1082 SNP and disease recurrence from previously stable disease and the level of steroids required for maintenance therapy. In addition, the GCC IL-10 promoter haplotype (IL-10 -1082G, -819C, -592C) was found to be protective against disease recurrence.

CONCLUSIONS

These results show that cytokine gene polymorphisms are markers for the severity of disease in SO. They were found to be associated with recurrence of previously stable disease and with the level of maintenance steroid treatment required to control inflammatory activity.