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AimTo describe the clinical and molecular features of a novel, autosomal dominant RDH12-retinopathy.MethodsRetrospective cross-sectional study. Twelve individuals from a four-generation British pedigree underwent ophthalmic examination, genotyping using next generation sequencing, including whole genome sequencing and multimodal retinal imaging including fundus photography, optical coherence tomography (OCT), autofluorescence imaging and adaptive optics (AO) scanning light ophthalmoscopy were performed. Visual electrophysiology was performed in a subset.ResultsEight family members were confirmed as affected by genotyping heterozygous for RDH12 c.763delG. Visual acuity ranged from −0.1 to 0.2 logMAR. Affected individuals had constricted visual fields. A parafoveal and peripapillary ring of hyper-autofluorescence was seen initially, and with progression the area of perifoveal hypo-autofluorescence increased to involve the parafoveal area. Mild retinal thinning was identified on OCT imaging with reduction in both foveal total retinal and outer nuclear layer thickness. Cone densities along the temporal meridian were reduced in affected individuals compared with normative values at all temporal eccentricities studied. One individual with incomplete penetrance, was identified as clinically affected primarily on the basis of AO imaging. Full-field electroretinography demonstrated a rod-cone pattern of dysfunction and large-field pattern electroretinography identified peripheral macular dysfunction.ConclusionsThis novel heterozygous variant RDH12 c.763delG is associated with a rod-cone dystrophy with variable expression. Determination of the degree of penetrance may depend on the modality employed to phenotypically characterise an individual. This rare and specific heterozygous (dominant) variant is predicted to result in a gain of function, that causes disease in a gene typically associated with biallelic (recessive) variants.

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the developed world. The identification of the central role of vascular endothelial growth factor (VEGF) in the pathogenesis of neovascular AMD and the introduction of anti-VEGF agents as gold-standard treatment, have drastically changed its prognosis—something yet to be seen in dry AMD. Several therapeutic avenues with a wide variability of targets are currently being investigated in dry AMD. The approaches being investigated to reduce the rate of disease progression include, (1) drugs with antioxidative properties, (2) inhibitors of the complement cascade, (3) neuroprotective agents, (4) visual cycle inhibitors, (5) gene therapy and (6) cell-based therapies. A number of early phase clinical trials have provided promising results, with many more ongoing and anticipated in the near future. In this review, we aim to provide an update of the interventional trials to date and future prospects for the treatment of dry AMD.

Background/aimsThe purpose of this study was to investigate retinal structure in detail of subjects with autosomal-dominant (AD) and autosomal-recessive (AR)PROM1-associated retinal degeneration (PROM1-RD), study design: institutional, cross-sectional study.MethodsFour eyes from four subjects (three with AD and one with AR)PROM1-RD were investigated by ophthalmic examination including best-corrected visual acuity (BCVA) and multimodal retinal imaging: fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT) and adaptive optics scanning light ophthalmoscopy. Quantitative assessment of atrophic lesions determined by FAF, thickness of individual retinal layers and cone photoreceptor quantification was performed.ResultsBCVA ranged from 20/16 to 20/200. Initial pathological changes included the presence of hyperautofluorescent spots on FAF imaging, while later stages demonstrated discrete areas of atrophy. In all patients, thinning of the outer retinal layers on SD-OCT with varying degrees of atrophy could be detected depending on disease-causing variants and age. Cone density was quantified both in central and/or at different eccentricities from the fovea. Longitudinal assessments were possible in two patients.ConclusionsPROM1-RD comprises a wide range of clinical phenotypes. Depending on the stage of disease, the cone mosaic inPROM1-RD is relatively preserved and can potentially be targeted by cone-directed interventions.

Macular dystrophies (MDs) consist of a heterogeneous group of disorders that are characterised by bilateral symmetrical central visual loss. Advances in genetic testing over the last decade have led to improved knowledge of the underlying molecular basis. The developments in high-resolution multimodal retinal imaging have also transformed our ability to make accurate and more timely diagnoses and more sensitive quantitative assessment of disease progression, and allowed the design of optimised clinical trial endpoints for novel therapeutic interventions. The aim of this review was to provide an update on MDs, including Stargardt disease, Best disease, X-linked r etinoschisis, pattern dystrophy, Sorsby fundus dystrophy and autosomal dominant drusen. It highlights the range of innovations in retinal imaging, genotype–phenotype and structure–function associations, animal models of disease and the multiple treatment strategies that are currently in clinical trial or planned in the near future, which are anticipated to lead to significant changes in the management of patients with MDs.

Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.

Background/AimsTo report the prevalence of treatable complications (cystoid macular oedema, CME; epiretinal membrane, ERM and cataract) in patients with retinitis pigmentosa (RP).MethodsConsecutive patients with RP attending a tertiary eye clinic in 2012. Spectral domain-optical coherence tomography was used to determine presence of CME and ERM. Clinic records were reviewed to identify cataract and pseudophakia. Multivariable analyses adjusted for age, gender and other confounders.ResultsData are presented for 338 eyes from 169 patients. CME was present in 58.6% of patients and 50.9% of eyes and was bilateral in 73.7%. ERM, cataract and pseudophakia were present in 22.8%, 23.4% and 11.2% eyes, respectively. In multivariable analyses, CME was associated with younger age (OR 0.81, 95% CI 0.67 to 0.98) but not with gender. Patients with ERM and cataract/pseudophakia were less likely to also have CME (OR 0.19, 95% CI 0.09 to 0.40 and OR 0.37, 95% CI 0.16 to 0.84, respectively). CME was most prevalent in patients with autosomal-dominant inheritance (71.4%), followed by autosomal recessive/sporadic inheritance (58.9%) and least likely in persons with X linked inheritance (12.5%, pConclusionsThe prevalence of treatable RP complications is high and suggests it may be clinically beneficial to screen patients with RP to identify those who may benefit from current or future interventions.

Background/aimsTo describe the genetic characteristics of the cohort enrolled in the international multicentre progression of Stargardt disease 1 (STGD1) studies (ProgStar) and to determine geographic differences based on the allele frequency.Methods345 participants with a clinical diagnosis of STGD1 and harbouring at least one disease-causing ABCA4 variant were enrolled from 9 centres in the USA and Europe. All variants were reviewed and in silico analysis was performed including allele frequency in public databases and pathogenicity predictions. Participants with multiple likely pathogenic variants were classified into four national subgroups (USA, UK, France, Germany), with subsequent comparison analysis of the allele frequency for each prevalent allele.Results211 likely pathogenic variants were identified in the total cohort, including missense (63%), splice site alteration (18%), stop (9%) and others. 50 variants were novel. Exclusively missense variants were detected in 139 (50%) of 279 patients with multiple pathogenic variants. The three most prevalent variants of these patients with multiple pathogenic variants were p.G1961E (15%), p.G863A (7%) and c.5461-10 T>C (5%). Subgroup analysis revealed a statistically significant difference between the four recruiting nations in the allele frequency of nine variants.ConclusionsThere is a large spectrum of ABCA4 sequence variants, including 50 novel variants, in a well-characterised cohort thereby further adding to the unique allelic heterogeneity in STGD1. Approximately half of the cohort harbours missense variants only, indicating a relatively mild phenotype of the ProgStar cohort. There are significant differences in allele frequencies between nations, although the three most prevalent variants are shared as frequent variants.

Background/aims Vitreous haemorrhage (VH) and retinal detachment (RD) cause a precipitous decline in vision in a subset of patients with X-linked retinoschisis (XLRS), an otherwise a slowly progressive condition. This study aims to report the frequency of macular and peripheral retinal findings in a large cohort of patients with XLRS and to determine whether peripheral retinal findings are associated with VH and RD. Methods A retrospective observational case series was performed in 65 patients with XLRS with a pathogenic variant in retinoschisin 1. Chart review included examination notes, fundus photographs and optical coherence tomography (OCT). Fisher exact tests and univariable logistic regression analysis were used to determine the association between peripheral retinal findings (including retinoschisis, metallic sheen, vascular sheathing, pigmentary changes, white spiculations and vitreous veils) and complications (including VH and RD). Results Seven eyes (8%) showed normal macular structure on OCT. Peripheral retinoschisis was significantly associated with both VH and RD. Out of 10 eyes with complications, 9 (90%) had peripheral retinoschisis, compared with 33 out of 116 eyes (28%) without complications (p=0.0014). In addition, each additional peripheral finding increased the odds of RD by a factor of 4.06 (95% CI 1.58 to 10.39, p=0.028). There were no complications in the 28 eyes with a normal periphery (p=0.84) or in the 35 eyes with metallic sheen (p=0.42). Conclusion The data suggest that patients with peripheral retinoschisis are at increased risk for VH and RD. Furthermore, patients with additional peripheral retinal findings together with peripheral schisis may carry additional risk for RD.

Background/aimsThe reason for visual impairment in patients with nanophthalmos and posterior microphthalmos is not completely understood. Therefore, this study aims to investigate foveal structure, and the impact of demographic, clinical and imaging parameters on best-corrected visual acuity (BCVA) in these conditions.MethodsSixty-two eyes of 33 patients with nanophthalmos (n=40) or posterior microphthalmos (n=22), and 114 eyes of healthy controls with high-resolution retinal imaging including spectral-domain or swept-source optical coherence tomography images were included in this cross-sectional case–control study. Foveal retinal layer thickness was determined by two independent readers. A mixed-effect model was used to perform structure–function correlations and predict the BCVA based on subject-specific variables.ResultsMost patients (28/33) had altered foveal structure associated with loss of foveal avascular zone and impaired BCVA. However, widening of outer nuclear layer, lengthening of photoreceptor outer segments, normal distribution of macular pigment and presence of Henle fibres were consistently found. Apart from the presence of choroidal effusion, which had significant impact on BCVA, the features age, refractive error, axial length and retinal layer thickness at the foveal centre explained 61.7% of the variability of BCVA.ConclusionThis study demonstrates that choroidal effusion, age, refractive error, axial length and retinal layer thickness are responsible for the majority of interindividual variability of BCVA as well as the morphological foveal heterogeneity in patients with nanophthalmos or posterior microphthalmos. This might give further insights into the physiology of foveal development and the process of emmetropisation, and support clinicians in the assessment of these disease entities.

Stargardt disease (STGD1; MIM 248200) is the most prevalent inherited macular dystrophy and is associated with disease-causing sequence variants in the gene ABCA4. Significant advances have been made over the last 10 years in our understanding of both the clinical and molecular features of STGD1, and also the underlying pathophysiology, which has culminated in ongoing and planned human clinical trials of novel therapies. The aims of this review are to describe the detailed phenotypic and genotypic characteristics of the disease, conventional and novel imaging findings, current knowledge of animal models and pathogenesis, and the multiple avenues of intervention being explored.

Background/AimsA subset of patients with X linked retinoschisis (XLRS) have bullous schisis cavities in the peripheral retina. This study describes the characteristics and prognosis of the bullous form of XLRS.MethodsA retrospective case series was performed of nine patients with molecularly proven bullous XLRS seen at a single tertiary centre.ResultsAll cases of bullous peripheral schisis were bilateral, with one unilateral case at presentation which developed into bilateral bullous schisis over time. The mean age of onset was 1.9 years (range: 1 month–7 years, SD: 2.1 years) and at clinical diagnosis was 5.9 years (range: 1 month–27 years, SD: 9.0 years). Mean follow-up was 11 years (range: 6 months–36 years, SD: 10.8 years). Strabismus was the most common presentation (n=7). Other presenting complaints included decreased vision, floaters and an irregularly shaped pupil. The most frequently associated ocular features were strabismus (100%), vitreous haemorrhage (4/18 eyes, 22%), nystagmus (2/9, 22%) and persistent fetal vasculature (1/18, 6%). Localised tractional detachment was seen in 2/18 (11%) eyes, total detachment that underwent surgical repair in 1/18 (6%) and pigmented demarcation lines in a further 22% of the eyes. There was one eye with exudative retinal detachment.ConclusionIn XLRS, bullous schisis may be congenital or develop soon after birth and most commonly presents with strabismus. Cases may be complicated by some form of retinal detachment, which may be tractional or a Coats-like exudative detachment.

Background/aims To present detailed phenotypic and molecular findings in four patients from four families with atypical, mild, recessive RPE65 -related retinal dystrophy and discuss potential implications for gene replacement therapy. Methods Four patients from four families with early onset retinal dystrophy underwent clinical examination, retinal imaging and electrophysiological testing. Bidirectional Sanger sequencing of all exons and intron–exon boundaries of RPE65 was performed. Results All patients presented with nyctalopia in early childhood but demonstrated a mild phenotype with good visual acuity until at least 19 years of age. All had generalised retinal dysfunction on electroretinography. Central macular thickness on optical coherence tomography was preserved in those patients with good visual acuity. One patient had extensive white dots throughout the retina reminiscent of fundus albipunctatus with electrophysiological evidence of partial recovery of rod function after prolonged dark adaptation. Sanger sequencing identified RPE65 mutations in all patients including three missense variants likely to represent hypomorphic alleles. Conclusions Hypomorphic mutations of RPE65 are associated with mild disease in childhood with preservation of good visual acuity into adulthood; they may in rare cases be associated with a flecked retina appearance similar to fundus albipunctatus. The presence of normal visual acuity in patients with hypomorphic mutations in RPE65 suggests that efficiency of transduction may not be the limiting factor in improving visual acuity in trials of gene replacement therapy. Rather, it suggests that for optimal recovery of visual acuity gene replacement therapy may need to be given much earlier in childhood.

BackgroundDefects in retinol dehydrogenase 12 (RDH12) account for 3.4%–10.5 % of Leber congenital amaurosis and early-onset severe retinal dystrophy (EOSRD) and are a potential target for gene therapy. Clinical trials in inherited retinal diseases have unique challenges, and natural history studies are critical to successful trial design. The purpose of this study was to characterise the natural history of RDH12-associated retinal degeneration.MethodsA retrospective chart review was performed in individuals with retinal degeneration and two likely disease-causing variants in RDH12.Results57 subjects were enrolled from nine countries. 33 subjects had clinical records available from childhood. The data revealed an EOSRD, with average age of onset of 4.1 years. Macular atrophy was a universal clinical finding in all subjects, as young as 2 years of age. Scotopic and photopic electroretinography (ERG) responses were markedly reduced in all subjects, and a non-recordable ERG was documented as young as 1 year of age. Assessment of visual acuity, visual field and optical coherence tomography revealed severe loss of function and structure in the majority of subjects after the age of 10 years. Widefield imaging in 23 subjects revealed a unique, variegated watercolour-like pattern of atrophy in 13 subjects and sparing of the peripapillary area in 18 subjects.ConclusionsThis study includes the largest collection of phenotypic data from children with RDH12-associated EOSRD and provides a comprehensive description of the timeline of vision loss in this severe, early-onset condition. These findings will help identify patients with RDH12-associated retinal degeneration and will inform future design of therapeutic trials.

Aim To report novel spectral domain optical coherence tomography (SD-OCT) findings and new mutational data in patients with ‘cone dystrophy with supernormal rod electroretinogram’, a recessive childhood onset retinal dystrophy consequent upon mutation in the KCNV2 gene. Design/methods This was a comparative case series study of 12 patients with clinical and/or electrophysiological findings in keeping with KCNV2 mutation. Clinical examination and electrophysiological testing results were reviewed. Fundus photography and autofluorescence imaging were performed. Retinal layer appearance and thickness were evaluated using SD-OCT. The coding region and intron–exon boundaries of KCNV2 were screened by direct sequencing. Results Mutations in KCNV2 were detected in all families; five of these changes were novel. Pattern electroretinograms were undetectable and full-field electroretinograms showed findings specific for the disorder. SD-OCT demonstrated bilateral morphological changes, usually confined to the fovea. Four foveal SD-OCT phenotypes were observed: (i) discontinuous inner and outer segment (IS/OS) junction reflectivity (6 patients), (ii) loss of IS/OS line and an optical gap in the foveola (2 patients); (iii) IS/OS junction disruption and profound foveal depth reduction, without optical gap and with preserved retinal pigment epithelium (RPE) complex (2 patients); and (iv) outer retina and RPE complex abnormalities (2 patients). Thinning of the neurosensory retina was observed in all eyes. Conclusion In KCNV2 retinopathy foveal morphological changes are evident on SD-OCT even in the early stages of disease. However, there appears to be a window of opportunity, before marked structural damage has occurred, during which novel therapeutic intervention, such as gene replacement therapy, may rescue retinal function.

Introduction: The mitochondrial DNA A3243G point mutation is associated with a wide variety of systemic manifestations including a macular dystrophy. The characteristics of fundus autofluorescence (AF) in these patients are distinctive and have not been previously described. Methods: A complete history and ophthalmic examination, including fundus photography and autofluorescence imaging, was performed on twelve probands harbouring the A3243G point mutation. Results: Four patients had diabetes, 10/12 hearing loss, and 7/12 were visually symptomatic. A positive family history was present in 5/12. Fundus findings consisted of two primary phenotypes: discontinuous circumferentially oriented perifoveal atrophy (9/12) or an appearance consistent with pattern dystrophy (3/12). In both phenotypes pale deposits and pigment clumping were seen at the level of the retinal pigment epithelium, with occasional changes also noted outside the arcades and nasal to the optic nerve. Fundus AF imaging revealed decreased autofluorescence in areas of atrophy and increased AF of the pale subretinal deposits. In areas of the retina that appeared normal clinically, variable sized flecks of increased and decreased AF were present. Conclusions: The mitochondrial DNA A3243G point mutation can result in disease with a variable presentation. Fundus autofluorescence reveals a recognisable phenotype in most cases that is different from other macular dystrophies.

Aim: To determine the frequency and nature of mutations in the gene ABCA4 in a cohort of patients with bull’s-eye maculopathy (BEM). Methods: A panel of 49 subjects (comprising 40 probands/families, 7 sibling pairs and a set of three sibs) with BEM, not attributable to toxic causes, was ascertained. Blood samples from each patient were used to extract genomic DNA, with subsequent mutation screening of the entire coding sequence of ABCA4 , using single-strand conformational polymorphism (SSCP) analysis and direct sequencing. Results: Fourteen probands (35%) were found to have a potentially disease-causing ABCA4 sequence variant on at least one allele. Three patients had a Gly1961Glu missense mutation, the most common variant in Stargardt disease (STGD), with 2 of these subjects having a macular dystrophy (MD) phenotype and a second ABCA4 variant previously associated with STGD. The second most common STGD mutation, Ala1038Val, was seen in one patient with cone–rod dystrophy (CORD). Five novel ABCA4 variants were detected. Two sibships were identified with a similar intra-familial phenotype but discordant ABCA4 variants. Conclusions: Variations in the ABCA4 gene are common in BEM. Two sibships showed discordant ABCA4 variants. One of these sibships illustrates that ABCA4 variants can be identified in families that have another molecular cause for their disease, due to the high prevalence of ABCA4 disease alleles in the population. The discordance evident in the second sibship may yet also be a chance finding in families with macular disease of another genetic cause, or it may represent a complex mode of inheritance determined/modified by the combination of ABCA4 alleles.

Aim: The aim of this study was to establish the functional significance of annular macular abnormalities present on fundus autofluorescence imaging (AF) in patients with cone or cone-rod dystrophy.Methods: Fundus AF was performed on ten subjects (age range 18-82 years) with cone or cone-rod dystrophy consequent upon RPGR or RIMS1 mutation. International-standard full-field and pattern electroretinograms (ERGs) were performed in all cases. Photopic and scotopic fine matrix mapping (FMM) and multifocal ERG were performed on selected cases.Results: Subjects had annuli of high density AF that bordered central areas of low density in older RPGR cases and most RIMS1 cases. The size of the AF ring correlated with age and enlarged with time in two subjects. High-density rings were associated with a gradient of scotopic and photopic sensitivity loss. Pattern electroretinogram (PERG) P50 amplitude, when detectable, was inversely related to the size of the AF ring. Multifocal ERGs in two subjects showed widespread reduction with relative sparing over the foveal area, in keeping with FMM data.Conclusions: Some patients with cone-rod dystrophy have a parafoveal ring of increased autofluorescence that may enlarge with time. Increased autofluorescence is associated with reduced rod and cone sensitivity, rather than photoreceptor cell death, and AF imaging may help identify viable areas of retina amenable to future therapeutic intervention.

The cone dystrophies comprise a heterogeneous group of disorders characterised by visual loss, abnormalities of colour vision, central scotomata, and a variable degree of nystagmus and photophobia. They may be stationary or progressive. The stationary cone dystrophies are better described as cone dysfunction syndromes since a dystrophy often describes a progressive process. These different syndromes encompass a wide range of clinical and psychophysical findings. The aim is to review current knowledge relating to the cone dysfunction syndromes, with discussion of the various phenotypes, the currently mapped genes, and genotype-phenotype relations. The cone dysfunction syndromes that will be discussed are complete and incomplete achromatopsia, oligocone trichromacy, cone monochromatism, blue cone monochromatism, and Bornholm eye disease. Disorders with a progressive cone dystrophy phenotype will not be discussed.

Pantothenate kinase-associated neurodegeneration (PKAN; OMIM 234200) is caused by recessive mutations in PANK2 and is characterised by dystonia, cerebral iron accumulation, pathognomonic ‘eye of the tiger’ MRI finding, and pigmentary retinal degeneration.1 2 Bone spicule formation, retinal vessel attenuation and yellow-white globular deposits seen clinically have been correlated histopathologically with degeneration of photoreceptors, marked outer retinal layer thinning and accumulation of melanolipofuscin.2 In keeping with these observations, electroretinographic abnormalities, ranging from mild cone to severe rod–cone dysfunction, have been reported.3 Retinal telangiectasis, also known as Coats'-like or Coats'-type exudative vasculopathy, may occur in both syndromic and non-syndromic retinitis pigmentosa.4 However, we are not aware of previous published reports of exudative vasculopathy associated with PKAN. We have characterised a patient with a novel mutation in PANK2 that had spontaneous resolution of retinal telangiectasis. In October 2005, a 10-year-old girl was referred to Moorfields Eye Hospital …

Background The onset of Leber hereditary optic neuropathy (LHON) is relatively rare in childhood. This study describes the clinical and molecular genetic features observed in this specific LHON subgroup.\ud \ud \ud Methods Our retrospective study consisted of a UK paediatric LHON cohort of 27 patients and 69 additional cases identified from a systematic review of the literature. Patients were included if visual loss occurred at the age of 12 years or younger with a confirmed pathogenic mitochondrial DNA mutation: m.3460G>A, m.11778G>A or m.14484T>C.\ud \ud \ud Results In the UK paediatric LHON cohort, three patterns of visual loss and progression were observed: (1) classical acute (17/27, 63%); (2) slowly progressive (4/27, 15%); and (3) insidious or subclinical (6/27, 22%). Diagnostic delays of 3–15 years occurred in children with an insidious mode of onset. Spontaneous visual recovery was more common in patients carrying the m.3460G>A and m.14484T>C mutations compared with the m.11778G>A mutation. Based a meta-analysis of 67 patients with available visual acuity data, 26 (39%) patients achieved a final best-corrected visual acuity (BCVA) ≥0.5 Snellen decimal in at least one eye, whereas 13 (19%) patients had a final BCVA