scholarly journals Leber congenital amaurosis/early-onset severe retinal dystrophy: current management and clinical trials

2021 ◽  
pp. bjophthalmol-2020-318483
Author(s):  
Malena Daich Varela ◽  
Thales Antonio Cabral de Guimaraes ◽  
Michalis Georgiou ◽  
Michel Michaelides
Keyword(s):  
Gene Therapy ◽  
Clinical Trials ◽  
Early Onset ◽  
Viral Vectors ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
European Medicines Agency ◽  
Current Management ◽  
Leber Congenital Amaurosis

Leber congenital amaurosis (LCA) is a severe congenital/early-onset retinal dystrophy. Given its monogenic nature and the immunological and anatomical privileges of the eye, LCA has been particularly targeted by cutting-edge research. In this review, we describe the current management of LCA, and highlight the clinical trials that are on-going and planned. RPE65-related LCA pivotal trials, which culminated in the first Food and Drug Administration-approved and European Medicines Agency-approved ocular gene therapy, have paved the way for a new era of genetic treatments in ophthalmology. At present, multiple clinical trials are available worldwide applying different techniques, aiming to achieve better outcomes and include more genes and variants. Genetic therapy is not only implementing gene supplementation by the use of adeno-associated viral vectors, but also clustered regularly interspaced short palindromic repeats (CRISPR)-mediated gene editing and post-transcriptional regulation through antisense oligonucleotides. Pharmacological approaches intending to decrease photoreceptor degeneration by supplementing 11-cis-retinal and cell therapy’s aim to replace the retinal pigment epithelium, providing a trophic and metabolic retinal structure, are also under investigation. Furthermore, optoelectric devices and optogenetics are also an option for patients with residual visual pathway. After more than 10 years since the first patient with LCA received gene therapy, we also discuss future challenges, such as the overlap between different techniques and the long-term durability of efficacy. The next 5 years are likely to be key to whether genetic therapies will achieve their full promise, and whether stem cell/cellular therapies will break through into clinical trial evaluation.

scholarly journals An Update on Gene Therapy for Inherited Retinal Dystrophy: Experience in Leber Congenital Amaurosis Clinical Trials

2021 ◽  
Vol 22 (9) ◽  
pp. 4534
Author(s):  
Wei Chiu ◽  
Ting-Yi Lin ◽  
Yun-Chia Chang ◽  
Henkie Isahwan-Ahmad Mulyadi Lai ◽  
Shen-Che Lin ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Clinical Trials ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Clinical Manifestations ◽  
Adeno Associated Virus ◽  
Leber Congenital Amaurosis ◽  
Gene Therapies

Inherited retinal dystrophies (IRDs) are a group of rare eye diseases caused by gene mutations that result in the degradation of cone and rod photoreceptors or the retinal pigment epithelium. Retinal degradation progress is often irreversible, with clinical manifestations including color or night blindness, peripheral visual defects and subsequent vision loss. Thus, gene therapies that restore functional retinal proteins by either replenishing unmutated genes or truncating mutated genes are needed. Coincidentally, the eye’s accessibility and immune-privileged status along with major advances in gene identification and gene delivery systems heralded gene therapies for IRDs. Among these clinical trials, voretigene neparvovec-rzyl (Luxturna), an adeno-associated virus vector-based gene therapy drug, was approved by the FDA for treating patients with confirmed biallelic RPE65 mutation-associated Leber Congenital Amaurosis (LCA) in 2017. This review includes current IRD gene therapy clinical trials and further summarizes preclinical studies and therapeutic strategies for LCA, including adeno-associated virus-based gene augmentation therapy, 11-cis-retinal replacement, RNA-based antisense oligonucleotide therapy and CRISPR-Cas9 gene-editing therapy. Understanding the gene therapy development for LCA may accelerate and predict the potential hurdles of future therapeutics translation. It may also serve as the template for the research and development of treatment for other IRDs.

Unusual presentation of early-onset X-linked retinoschisis: Report after 1 year of multimodal follow-up

2020 ◽  
pp. 112067212091672
Author(s):  
Andrea Lembo ◽  
Giacomo Maria Bacci ◽  
Massimiliano Serafino ◽  
Stefano Lucentini ◽  
Roberto Caputo ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Early Onset ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Unusual Presentation ◽  
Macular Dystrophy ◽  
Wide Field ◽  
The Right

Purpose: To describe the unusual presentation, diagnosis, and clinical course of an early-onset X-linked infantile retinoschisis Case report: A 6-month-old infant presented with strabismus and poor fixation. After the detection of bilateral intraretinal hemorrhage and diffuse dystrophic retinal pattern at indirect ophthalmoscopy, the patient received a complete evaluation under anesthesia. Retinal wide-field imaging, spectral domain optical coherence tomography, and electroretinogram were performed and revealed a retinoschisis involving the posterior pole and the inferior periphery in the right eye. In the left eye, an inferior retinal detachment extending to the macula was detected. Blood sample and genetic counseling were required in the strong suspicion of an inherited retinal dystrophy. Genetic tests confirmed the diagnosis of X-linked retinoschisis (RS1 gene mutation). After consultation with a pediatric vitreoretinal surgeon, a wait and see strategy was chosen. The follow up visits showed a surprisingly good natural course of the disease. Conclusion: X-linked retinoschisis is a well-known inherited retinal disease potentially affecting young children as early as 3 months old. In this case, the stunning presentation (diffuse retinal pigment epithelium dystrophic changes resembling a macular dystrophy) and the positive course of the disease (resolution of macular retinal detachment in the left eye and stability of schisis in the right eye) arise some interesting considerations about the necessity of an early surgical treatment.

scholarly journals Adeno-Associated Viral Vectors as a Tool for Large Gene Delivery to the Retina

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 287 ◽  
Author(s):  
Trapani
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Diseases ◽  
Considerable Effort ◽  
Safety And Efficacy ◽  
Large Gene ◽  
Packaging Capacity ◽  
Large Genes

Gene therapy using adeno-associated viral (AAV) vectors currently represents the most promising approach for the treatment of many inherited retinal diseases (IRDs), given AAV’s ability to efficiently deliver therapeutic genes to both photoreceptors and retinal pigment epithelium, and their excellent safety and efficacy profiles in humans. However, one of the main obstacles to widespread AAV application is their limited packaging capacity, which precludes their use from the treatment of IRDs which are caused by mutations in genes whose coding sequence exceeds 5 kb. Therefore, in recent years, considerable effort has been made to identify strategies to increase the transfer capacity of AAV vectors. This review will discuss these new developed strategies, highlighting the advancements as well as the limitations that the field has still to overcome to finally expand the applicability of AAV vectors to IRDs due to mutations in large genes.

Chronic untreated retinal detachment in a patient with choroideremia provides insight into the disease process and potential therapy

2021 ◽  
pp. 112067212199472
Author(s):  
Maria Pilar Martin-Gutierrez ◽  
Thomas MW Buckley ◽  
Robert E MacLaren
Keyword(s):  
Gene Therapy ◽  
Retinal Detachment ◽  
Rhegmatogenous Retinal Detachment ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Disease Process ◽  
Peripheral Retina ◽  
Inherited Retinal Dystrophy ◽  
Insight Into

Aim: We present the case of a 72-year-old male with advanced choroideremia and a left chronic rhegmatogenous retinal detachment, which to our knowledge is the first formal report of a retinal detachment in this disease. Background: Choroideremia is a rare X-linked inherited retinal dystrophy, caused by mutations in the CHM gene which encodes Rab escort protein 1 (REP1), and affected males typically experience a progressive centripetal loss of vision. The disease pathology is caused by a primary retinal pigment epithelium degeneration, which leads to secondary loss of photoreceptors and choriocapillaris. This in turn leads to fusion of the degenerate outer retinal layers resulting in a retinopexy that is known to make subretinal gene therapy particularly challenging in these patients. Conclusion: Although retinal gene therapy is commonly targeted to the macular area in choroideremia, the observation of a rhegmatogenous retinal detachment indicates that the peripheral retina may not fuse with the residual choroid as occurs in the equatorial and macular regions. If this hypothesis is correct, targeting gene therapy to the retinal periphery even in advanced cases may be feasible and could potentially be used to preserve navigational vision.

scholarly journals Molecular Screening of 43 Brazilian Families Diagnosed with Leber Congenital Amaurosis or Early-Onset Severe Retinal Dystrophy

Genes ◽  
2017 ◽  
Vol 8 (12) ◽  
pp. 355 ◽  
Author(s):  
Fernanda Porto ◽  
Evan Jones ◽  
Justin Branch ◽  
Zachry Soens ◽  
Igor Maia ◽  
...  
Keyword(s):  
Early Onset ◽  
Retinal Dystrophy ◽  
Molecular Screening ◽  
Leber Congenital Amaurosis

Genetic and clinical findings in a Chinese cohort with Leber congenital amaurosis and early onset severe retinal dystrophy

2019 ◽  
Vol 104 (7) ◽  
pp. 932-937 ◽  
Author(s):  
Ke Xu ◽  
Yue Xie ◽  
Tengyang Sun ◽  
Xiaohui Zhang ◽  
Chunjie Chen ◽  
...  
Keyword(s):  
Early Onset ◽  
Retinal Dystrophy ◽  
Case Series ◽  
Clinical Findings ◽  
Chinese Patients ◽  
Pcr Analysis ◽  
Common Mutation ◽  
Essential Information ◽  
Leber Congenital Amaurosis ◽  
Targeted Next Generation Sequencing

BackgroundLeber congenital amaurosis (LCA) and early onset severe retinal dystrophy (EOSRD) are clinically and genetically heterogeneous inherited retinal disorders that cause severe visual impairment in children. The objective of this study was to describe the mutation profile and phenotypic characteristics in Chinese patients with LCA or EOSRD.MethodsRetrospective consecutive case series (2010–2017) study was performed in 148 probands (91 with LCA and 57 with EOSRD). All patients underwent ophthalmic evaluation. Mutations were revealed using targeted next-generation sequencing, followed by Sanger DNA-sequencing and real-time quantitative PCR analysis.ResultsWe identified two diseasing-causing mutations in 88 unrelated patients, heterozygous autosomal dominant mutations in 11 probands and X-linked hemizygous mutations in 11 patients, for an overall mutation detection rate of 74.3% (110/148). We detected 158 different disease-causing mutations involving 14 LCA genes, 16 retinitis pigmentosa or cone-rod dystrophy genes and 3 syndromic retinal dystrophy genes. Of these 158 mutations, 98 were novel. The most common mutation was p.Q141X of AIPL1, with a gene-specific allele frequency of 60%. The first five most frequently mutated genes were AIPL1 (11.0%), RPGRIP1 (8.8%) and CEP290, GUCY2D and RPE65 (each 7.7%) in the patients with LCA and RPGR (12.3%), CRB1 (10.5%), RPE65 (10.5%), RDH12 (7.0%) and RP2 (5.3%) in the patients with EOSRD.ConclusionsOur results revealed that the mutation spectrum of patients with LCA differs from that of the patients with EOSRD and established the configuration of the mutation frequencies for each LCA gene in Chinese patients, thereby providing essential information for future genetic counselling and gene therapy.

Diffuse Pigmented Lesions in the Outer Retina: An Unusual Fundus Appearance

2019 ◽  
Vol 4 (3) ◽  
pp. 243-247
Author(s):  
Matthew D. Benson ◽  
Uriel Rubin ◽  
Marvi Cheema ◽  
Ian M. MacDonald ◽  
Matthew T.S. Tennant ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Full Field ◽  
Panel Testing ◽  
Pigmented Lesions ◽  
Hereditary Retinal Dystrophy ◽  
Ultrasound Findings ◽  
Chest X Ray

Purpose: This report describes and provides a differential diagnosis for a patient with unusual bilateral retinal pigmented lesions. Methods: A 40-year-old woman was found to have multiple flat, gray lesions scattered across her fundi, becoming larger and more confluent toward the periphery. There were small drusenlike deposits in her foveae. The hyperpigmented lesions demonstrated hypoautofluorescence with thickening of the retinal pigment epithelium and disruption of the overlying layers on optical coherence tomography (OCT). Full-field electroretinography revealed generalized reduced a- and b-wave amplitudes. Results: Chest x-ray, breast ultrasound, mammography, and pelvic ultrasound findings were negative for malignant etiologic factors. Panel testing results for hereditary retinal dystrophy were negative. Conclusions: Although the clinical and OCT appearance of the lesions is similar to congenital grouped pigmentation, the symmetric and bilateral nature of ocular findings coupled with electroretinographic changes suggest a possible retinal dystrophy. This case adds to the phenotypic diversity of pigmented fundus lesions.

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