An osmolarity dependent mechanism partially ameliorates retinal cysts and rescues cone function in a mouse model of X-linked retinoschisis.

Introduction: X-linked retinoschisis (XLRS) is a vitreoretinal dystrophy caused by gene mutations which disrupt retinoschisin-1 (RS1) function. Vital for retinal architecture, the absence of functional RS1 leads to the development of intraretinal cysts. Intravitreal injection of a gene therapy for treating XLRS caused ocular inflammation in high dose groups in a phase I/II clinical trial.

Delivering large genes using adeno-associated virus and the CRE-lox DNA recombination system.

Adeno-associated virus (AAV) is a safe and efficient gene delivery vehicle for gene therapies. However, its relatively small packaging capacity limits its use as a gene transfer vector. Here, we describe a strategy to deliver large genes that exceed the AAV's packaging capacity using up to four AAV vectors and the CRE-lox DNA recombination system.

Contribution of intraflagellar transport to compartmentalization and maintenance of the photoreceptor cell.

The first steps of vision take place in the ciliary outer segment compartment of photoreceptor cells. The protein composition of outer segments is uniquely suited to perform this function. The most abundant among these proteins is the visual pigment, rhodopsin, whose outer segment trafficking involves intraflagellar transport (IFT).

The long-term outcomes of the Anderson-Kestenbaum procedure.

Introduction: Nystagmus is an involuntary, conjugated, rhythmic movement of the eye that can be idiopathic or secondary to ocular or neurologic pathologies. Patients with nystagmus often have a position of gaze in which their symptoms are dampened or absent, referred to as the "null zone." The Anderson-Kestenbaum procedure is a bilateral recess-resect procedure of the four horizontal rectus muscles which aims to bring the null position into the primary gaze.

Investigating the role of Caspase-1 in a mouse model of Juvenile X-linked Retinoschisis.

Purpose: Previous studies have reported Caspase-1 () is upregulated in mouse models of Juvenile X-linked Retinoschisis (XLRS), however no functional role for in disease progression has been identified. We performed electroretinogram (ERG) and standardized optical coherence tomography (OCT) in mice deficient in the Retinoschisin-1 () and and Caspase-11 genes (-KO ) to test the hypothesis that may play a role in disease evolution and or severity of disease. Currently, no studies have ventured to investigate the longer-term effects of on phenotypic severity and disease progression over time in XLRS, and specifically the effect on electroretinogram.

Delivering large genes using adeno-associated virus and the CRE-lox DNA recombination system.

Adeno-associated virus (AAV) is a safe and efficient gene delivery vehicle for gene therapies. However, its relatively small packaging capacity limits its use as a gene transfer vector. Here, we describe a strategy to deliver large genes that exceed the AAV's packaging capacity using up to four AAV vectors and the CRE-lox DNA recombination system.

Quantitative Foveal Structural Metrics as Predictors of Visual Acuity in Human Albinism.

Purpose: To assess the degree to which quantitative foveal structural measurements account for variation in best-corrected visual acuity (BCVA) in human albinism.

Methods: BCVA was measured and spectral domain optical coherence tomography (SD-OCT) images were acquired for 74 individuals with albinism. Categorical foveal hypoplasia grades were assessed using the Leicester Grading System for Foveal Hypoplasia.

The dose-response relationship of subretinal gene therapy with rAAV2tYF-CB-h in a mouse model of X-linked retinoschisis.

Purpose: X-linked retinoschisis (XLRS), due to loss-of-function mutations in the retinoschisin () gene, is characterized by a modest to severe decrease in visual acuity. Clinical trials for XLRS utilizing intravitreal (IVT) gene therapy showed ocular inflammation. We conducted a subretinal dose-response preclinical study using rAAV2tYF-CB-h utilizing the knockout (-KO) mouse to investigate short- and long-term retinal rescue after subretinal gene delivery.

A Retrospective Longitudinal Study of 460 Patients with ABCA4-Associated Retinal Disease.

Purpose: To investigate the distribution of genotypes and natural history of ABCA4-associated retinal disease in a large cohort of patients seen at a single institution.

Design: Retrospective, single-institution cohort review.

Participants: Patients seen at the University of Iowa between November 1986 and August 2022 clinically suspected to have disease caused by sequence variations in ABCA4.

CACNA1F-related synaptic dysfunction: challenges diagnosing congenital stationary night blindness presenting without night blindness.

Objective: To describe pediatric patients with CACNA1F-associated incomplete X-linked congenital stationary night blindness presenting without nyctalopia, and review the causes leading to diagnosis delay.

Design: Retrospective cohort.

Methods: This was set in a single institution between 2004 and 2019.

A visually guided swim assay for mouse models of human retinal disease recapitulates the multi-luminance mobility test in humans.

Purpose: The purpose of this study was to develop a visually guided swim assay (VGSA) for measuring vision in mouse retinal disease models comparable to the multi-luminance mobility test (MLMT) utilized in human clinical trials.

Methods: Three mouse retinal disease models were studied: Bardet-Biedl syndrome type 1 (), = 5; Bardet-Biedl syndrome type 10 (), = 11; and X linked retinoschisis (retinoschisin knockout; KO), = 5. Controls were normally-sighted mice, = 10.

GJA3 Genetic Variation and Autosomal Dominant Congenital Cataracts and Glaucoma Following Cataract Surgery.

Importance: The p.Asp67Tyr genetic variant in the GJA3 gene is responsible for congenital cataracts in a family with a high incidence of glaucoma following cataract surgery.

Objective: To describe the clinical features of a family with a strong association between congenital cataracts and glaucoma following cataract surgery secondary to a genetic variant in the GJA3 gene (NM_021954.

Long-term functional and structural outcomes in X-linked retinoschisis: implications for clinical trials.

Introduction: X-linked retinoschisis (XLRS) is an inherited retinal disease (IRD) caused by pathogenic mutations in the retinoschisin gene, . Affected individuals develop retinal layer separation, leading to loss of visual acuity (VA). Several XLRS gene therapy trials have been attempted but none have met their primary endpoints.

Prevalence of cerebrotendinous xanthomatosis among patients diagnosed with early-onset idiopathic bilateral cataracts: final analysis.

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive bile acid synthesis disorder caused by pathologic variants in CYP27A1, a gene involved in bile acid synthesis. Impaired function in this gene leads to accumulation of plasma cholestanol (PC) in various tissues, often in early childhood, resulting in such clinical signs as infantile diarrhea, early-onset bilateral cataracts, and neurological deterioration. The current study aimed to identify cases of CTX in a population of patients with a greater CTX prevalence than the general population, to facilitate early diagnosis.

A novel porcine model of CLN3 Batten disease recapitulates clinical phenotypes.

Mouse models of CLN3 Batten disease, a rare lysosomal storage disorder with no cure, have improved our understanding of CLN3 biology and therapeutics through their ease of use and a consistent display of cellular pathology. However, the translatability of murine models is limited by disparities in anatomy, body size, life span and inconsistent subtle behavior deficits that can be difficult to detect in CLN3 mutant mouse models, thereby limiting their use in preclinical studies. Here, we present a longitudinal characterization of a novel miniswine model of CLN3 disease that recapitulates the most common human pathogenic variant, an exon 7-8 deletion (CLN3Δex7/8).

Subretinal gene therapy delays vision loss in a Bardet-Biedl Syndrome type 10 mouse model.

Blindness in Bardet-Biedl syndrome (BBS) is caused by dysfunction and loss of photoreceptor cells in the retina. , mutations of which account for approximately 21% of all BBS cases, encodes a chaperonin protein indispensable for the assembly of the BBSome, a cargo adaptor important for ciliary trafficking. The loss of BBSome function in the eye causes a reduced light sensitivity of photoreceptor cells, photoreceptor ciliary malformation, dysfunctional ciliary trafficking, and photoreceptor cell death.

Alström syndrome caused by maternal uniparental disomy.

Purpose: To describe a case of Alström syndrome arising from maternal uniparental disomy.

Observations: A 13-month-old boy with poor vision and nystagmus was diagnosed with Alström syndrome based on genetic testing that identified a homozygous pathogenic variant, c.2141_2141del (p.

AAV2/4-RS1 gene therapy in the retinoschisin knockout mouse model of X-linked retinoschisis.

Objective: To evaluate efficacy of a novel adeno-associated virus (AAV) vector, AAV2/4-RS1, for retinal rescue in the retinoschisin knockout (Rs1-KO) mouse model of X-linked retinoschisis (XLRS). Brinzolamide (Azopt®), a carbonic anhydrase inhibitor, was tested for its ability to potentiate the effects of AAV2/4-RS1.

Methods: AAV2/4-RS1 with a cytomegalovirus (CMV) promoter (2x1012 viral genomes/mL) was delivered to Rs1-KO mice via intravitreal (N = 5; 1μL) or subretinal (N = 21; 2μL) injections at postnatal day 60-90.

Electroretinogram abnormalities in FKRP-related limb-girdle muscular dystrophy (LGMDR9).

Background: Dystroglycanopathies are a heterogeneous group of membrane-related muscular dystrophies. The dystroglycanopathy phenotype includes a spectrum of severity ranging from severe congenital muscular dystrophy to adult-onset limb-girdle muscular dystrophy (LGMD). LGMDR9 is a dystroglycanopathy caused by mutations in the FKRP gene.

Restoration of Cone Sensitivity to Individuals with Congenital Photoreceptor Blindness within the Phase 1/2 Sepofarsen Trial.

Purpose: To understand consequences of reconstituting cone photoreceptor function in congenital binocular blindness resulting from mutations in the () gene.

Design: Phase 1b/2 open-label, multicenter, multiple-dose, dose-escalation trial.

Participants: A homogeneous subgroup of 5 participants with light perception (LP) vision at the time of enrollment (age range, 15-41 years) selected for detailed analyses.

Progressive retinal degeneration of rods and cones in a Bardet-Biedl syndrome type 10 mouse model.

Bardet-Biedl syndrome (BBS) is a multi-organ autosomal-recessive disorder caused by mutations in at least 22 different genes. A constant feature is early-onset retinal degeneration leading to blindness. Among the most common forms is BBS type 10 (BBS10), which is caused by mutations in a gene encoding a chaperonin-like protein.

Intravitreal antisense oligonucleotide sepofarsen in Leber congenital amaurosis type 10: a phase 1b/2 trial.

CEP290-associated Leber congenital amaurosis type 10 (LCA10) is a retinal disease resulting in childhood blindness. Sepofarsen is an RNA antisense oligonucleotide targeting the c.2991+1655A>G variant in the CEP290 gene to treat LCA10.

Bilateral visual loss, behavioral changes, and overlooking in a young child with stargardt disease: Neurodiagnostic considerations.

Purpose: To illustrate the potential diagnostic confusion between Batten disease and Stargardt disease created by associated signs and symptoms.

Observations: A six-year-old girl with vision loss and prominent behavioral changes and overlooking was presumptively diagnosed as having the Batten disease form of neuronal ceroid lipofuscinosis. However, genetic testing confirmed the diagnosis of Stargardt disease.

Comparative Natural History of Visual Function From Patients With Biallelic Variants in BBS1 and BBS10.

Purpose: The purpose of this study was to compare the natural history of visual function change in cohorts of patients affected with retinal degeneration due to biallelic variants in Bardet-Biedl syndrome genes: BBS1 and BBS10.

Methods: Patients were recruited from nine academic centers from six countries (Belgium, Canada, France, New Zealand, Switzerland, and the United States). Inclusion criteria were: (1) female or male patients with a clinical diagnosis of retinal dystrophy, (2) biallelic disease-causing variants in BBS1 or BBS10, and (3) measures of visual function for at least one visit.