Stargardt

Variants in ATP-binding cassette transporter type A4 ( ABCA4 ) have been linked to several forms of inherited retinal diseases (IRDs) besides the classically defined Stargardt disease (STGD), known collectively as ABCA4 retinopathies. ABCA4 is a sizable locus harboring 50 exons; thus, its analysis has revealed over 2,400 variants described, of which more than 2,000 are causal. Due to the clinical and genetic heterogeneity, diagnosing ABCA4 retinopathies is challenging. To date, no ABCA4 -related retinopathy has been detected in Lebanon...

Artificial intelligence (AI) has emerged as a transformative tool in the field of ophthalmology, revolutionizing disease diagnosis and management. This paper provides a comprehensive overview of AI applications in various retinal diseases, highlighting its potential to enhance screening efficiency, facilitate early diagnosis, and improve patient outcomes. Herein, we elucidate the fundamental concepts of AI, including machine learning (ML) and deep learning (DL), and their application in ophthalmology, underscoring the significance of AI-driven solutions in addressing the complexity and variability of retinal diseases...

ABCA4-related retinopathy is the most common inherited Mendelian eye disorder worldwide, caused by biallelic variants in the ATP-binding cassette transporter ABCA4. To date, over 2200 ABCA4 variants have been identified, including missense, nonsense, indels, splice site and deep intronic defects. Notably, more than 60% are missense variants that can lead to protein misfolding, mistrafficking and degradation. Currently no approved therapies target ABCA4. In this study, we demonstrate that ABCA4 misfolding variants are temperature-sensitive and reduced temperature growth (30 °C) improves their traffic to the plasma membrane, suggesting the folding of these variants could be rescuable...

The diagnosis of inherited retinal degeneration (IRD) is challenging owing to its phenotypic and genotypic complexity. Clinical information is important before a genetic diagnosis is made. Metabolomics studies the entire picture of bioproducts, which are determined using genetic codes and biological reactions. We demonstrated that the common diagnoses of IRD, including retinitis pigmentosa (RP), cone-rod dystrophy (CRD), Stargardt disease (STGD), and Bietti's crystalline dystrophy (BCD), could be differentiated based on their metabolite heatmaps...

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Mutations in ABCA4 gene leads to the most common form of an inherited retinal disease namely, the Stargardt disease, type 1. Here, we report the generation of two different patient-specific induced pluripotent stem cell lines (LVPEIi007-B and LVPEIi008-B), carrying an identical homozygous mutation, (c.6088C>T) within the exon 44 of ABCA4 gene. These lines were generated by the reprogramming of patient-specific dermal fibroblasts, using the integration-free, Sendai viral vectors. Both lines were stably expanded and expressed the stemness and pluripotency markers, differentiated into cell types of all three germ layers, and maintained a normal karyotype...

Precision medicine is rapidly gaining recognition in the field of (ultra)rare conditions, where only a few individuals in the world are affected. Clinical trial design for a small number of patients is extremely challenging, and for this reason, the development of N-of-1 strategies is explored to accelerate customized therapy design for rare cases. A strong candidate for this approach is Stargardt disease (STGD1), an autosomal recessive macular degeneration characterized by high genetic and phenotypic heterogeneity...

IMPORTANCE: Previous studies indicated that female sex might be a modifier in Stargardt disease, which is an ABCA4-associated retinopathy. OBJECTIVE: To investigate whether women are overrepresented among individuals with ABCA4-associated retinopathy who are carrying at least 1 mild allele or carrying nonmild alleles. DATA SOURCES: Literature data, data from 2 European centers, and a new study. Data from a Radboudumc database and from the Rotterdam Eye Hospital were used for exploratory hypothesis testing...

PURPOSE: The aim of this study was to estimate the number of patients in Japan who had visited an ophthalmologist for macular dystrophy of various types, including Best vitelliform macular dystrophy (BVMD), Stargardt disease, occult macular dystrophy (OMD), cone (-rod) dystrophy, X-linked retinoschisis (XLRS), and central areolar choroid dystrophy (CACD). STUDY DESIGN: Nationwide epidemiologic survey METHODS: Questionnaires were distributed to 965 major facilities, including all the university hospitals in Japan...

We causally analyzed whether being a member of the European Union (EU) and having access to a centralized marketing authorization procedure (centralized procedure [CP]) affects availability and time to launch of new pharmaceuticals. We employed multiple difference-in-differences models, exploiting the eastern enlargement of the EU as well as changes in the indications that fall within the compulsory or voluntary scope of the CP. Results showed that countries experienced a mean decrease in launch delay of 10...

PURPOSE: To investigate the temporal sequence of changes in the photoreceptor cell mosaic in patients with Stargardt disease type 1 (STGD1), using adaptive optics scanning laser ophthalmoscopy (AOSLO). METHODS: Two brothers with genetically confirmed STGD1 underwent comprehensive eye exams, spectral-domain optical coherence tomography (SD-OCT), fundus auto fluorescence (FAF) and AOSLO imaging 3 times over the course of 28 months. Confocal images of the cones and rods were obtained from the central fovea to 10 degrees inferiorly...

Pathogenic variants in ABCA4 are the underlying molecular cause of Stargardt disease (STGD1), an autosomal recessive macular dystrophy characterized by a progressive loss of central vision. Among intronic ABCA4 variants, c.4253+43G>A is frequently detected in STGD1 cases and is classified as a hypomorphic allele, generally associated with late-onset cases. This variant was previously reported to alter splicing regulatory sequences, but the splicing outcome is not fully understood yet. In this study, we attempted to better understand its effect on splicing and to rescue the aberrant splicing via antisense oligonucleotides (AONs)...

Background Inherited retinal diseases (IRD) represent a prominent etiology of visual impairment on a global scale. The lack of a clear definition of the etiology and genotypic spectrum of IRD is attributed to the significant genetic variability seen. Additionally, there is a scarcity of available data about the correlations between genotypes and phenotypes in this context. This study aimed to clarify the range of mutations and the associations between genotypes and phenotypes in IRD. Methods This cohort consists of 223 patients who have been diagnosed with a range of retinal illnesses, such as retinitis pigmentosa (RP), Stargardt (STGD)/STGD-like disease, Usher syndrome, and Leber congenital amaurosis (LCA)...

OBJECTIVES: Economic evaluations using broader measures to capture benefits beyond improved health can inform policy-making, but only if the monetary value of gains measured using these instruments is understood. This study explored contingent valuation as a method to estimate the monetary value of a wellbeing-adjusted life year (WALY) as measured by ICECAP-A. METHODS: In a large online survey of representative samples from seven European countries, participants valued a change in the ICECAP-A from their current health state to a randomly assigned hypothetical state...

OBJECTIVE: Current gene therapy of inherited retinal diseases is achieved mainly by subretinal injection, which is invasive with severe adverse effects. Intravitreal injection is a minimally invasive alternative for gene therapy of inherited retinal diseases. This work explores the efficacy of intravitreal delivery of PEGylated ECO (a multifunctional pH-sensitive amphiphilic amino lipid) plasmid DNA (pGRK1-ABCA4-S/MAR) nanoparticles (PEG-ELNP) for gene therapy of Stargardt disease. METHODS: Pigmented Abca4-/- knockout mice received 1 µL of PEG-ELNP solution (200 ng/uL, pDNA concentration) by intravitreal injections at an interval of 1...

BACKGROUND: Retinal degenerative disorders (RDDs) cause vision loss by damaging retinal neurons and photoreceptors, affecting individuals of all ages. Cell-based therapy has emerged as an effective approach for the treatment of RDDs with promising results. This meta-analysis aims to comprehensively evaluate the efficacy of cell therapy in treating age-related macular degeneration (AMD), retinitis pigmentosa (RP), and Stargardt macular degeneration (SMD) as the most prevalent RDDs. METHODS: PubMed, Scopus, Web of Science, and Embase were searched using keywords related to various retinal diseases and cell therapy treatments until November 25th, 2023...

BACKGROUND: IBDBIO-ASSIST was a randomised controlled trial assessing the efficacy of care provided by IBD nurse specialists in Germany in improving health-related quality of life (QoL) in IBD patients on biologic therapy. AIM: To evaluate patient-related outcomes and economic consequences associated with integrating IBD nurses into usual care. METHODS: We randomly assigned 1086 patients with IBD on biologic therapy to a control group (CG) receiving usual care or an intervention group (IG) receiving additional care from an IBD nurse specialist...

PURPOSE: To present the multimodal imaging and functional exam findings in a case of combined Stargardt disease and idiopathic intracranial hypertension. METHODS: The patient was evaluated with multimodal imaging including color fundus photography, short wavelength autofluorescence, spectral domain optical coherence tomography as well as functional testing such as Humphrey visual fields and full-field electroretinogram. RESULTS: A 35-year-old woman was referred for evaluation of bilateral transient visual obscurations over the course of 2 months...

PURPOSE: To classify fleck lesions and assess artificial intelligence (AI) in identifying flecks in Stargardt disease (STGD). METHODS: A retrospective study of 170 eyes from 85 consecutive patients with confirmed STGD. Fundus autofluorescence images were extracted, and flecks were manually outlined. A deep learning model was trained, and a hold-out testing subset was used to compare with manually identified flecks and for graders to assess. Flecks were clustered using K-means clustering...

Stargardt disease and age-related macular degeneration are the leading causes of blindness in the juvenile and geriatric populations, respectively. The formation of atrophic regions of the macula is a hallmark of the end-stages of both diseases. The progression of these diseases is tracked using various imaging modalities, two of the most common being fundus autofluorescence (FAF) imaging and spectral-domain optical coherence tomography (SD-OCT). This study seeks to investigate the use of longitudinal FAF and SD-OCT imaging (month 0, month 6, month 12, and month 18) data for the predictive modelling of future atrophy in Stargardt and geographic atrophy...