The corneal endothelium maintains corneal transparency and vision. Hereditary corneal dystrophies, including macular corneal dystrophy (MCD), Fuchs endothelial corneal dystrophy (FECD), and congenital hereditary endothelial dystrophy (CHED), cause progressive endothelial dysfunction, for which corneal transplantation is currently the main treatment. We evaluate an adeno-associated virus (AAV)-based gene therapy approach in preclinical models of MCD, FECD, and CHED. A refined intracameral injection method enables uniform endothelial transduction without corneal puncture. A single AAV6 administration supports sustained transgene expression in the corneal endothelium for over 18 months without detectable adverse immune responses. In MCD mice, AAV6-Chst5 reduces corneal opacification and restores keratan sulfate levels. In FECD mice, AAV6-Col8a2 prevents corneal opacity in 87.5% of treated eyes. In the CHED model, AAV6-Slc4a11 resolves corneal edema within 7 days. Single-cell RNA sequencing identifies Wnt5a as a downstream factor associated with MCD pathogenesis. These findings support the therapeutic potential of endothelial-targeted gene delivery for corneal endothelial disorders.

To assess the impact of MitoQ, a mitochondria-targeted antioxidant, on viability of human corneal endothelial cell (hCEnC) lines expressing SLC4A11 mutations associated with congenital hereditary endothelial dystrophy (CHED) and Fuchs endothelial corneal dystrophy type 4 (FECD4). SLC4A11 wildtype (SLC4A11WT) and mutant (SLC4A11MU) hCEnC lines were created to express either SLC4A11 variant 2 (V2) or variant 3 (V3) by stable transduction of SLC4A11-/- hCEnC-21T with lentiviruses containing either SLC4A11WT or one of the following mutations: V2 (V3) mutants c.374 G>A (c.326 G>A) (CHED), c.1813C>T (c.1765C>T) (CHED), c.2263C>T (c.2215C>T) (CHED), or c.2224 G>A (c.2176 G>A) (FECD4). A SLC4A11-/- empty hCEnC line was created by stable transduction of SLC4A11-/- hCEnC-21T with an empty lentiviral plasmid. Cell viability was measured by exposing MitoQ treated and untreated cells to oxidative stress agent tert-butyl hydroperoxide (tBH) followed by performing XTT assays and spectrophotometry. SLC4A11-/- empty, SLC4A11 V2WT, and SLC4A11 V3WT hCEnC exposed to ≤0.01 μM MitoQ retained over 90% of the viability of untreated SLC4A11-/- empty hCEnC. When treated with MitoQ, SLC4A11-/- empty was able to demonstrate partial restoration of cell viability. All CHED-associated mutant hCEnC lines treated with 0.01 μM MitoQ demonstrated increased viability compared to untreated following exposure to tBH. The FECD4-associated mutant hCEnC line treated with 0.01 μM MitoQ showed no significant increase in cell viability compared to untreated following exposure to tBH. Media supplementation with antioxidant MitoQ has beneficial effects on cell viability in hCEnC harboring CHED-associated SLC4A11 mutations following exposure to tBH-induced oxidative stress.

Mutations in the solute linked carrier family 4 member 11 (SLC4A11) gene are associated with congenital hereditary endothelial dystrophy (CHED) and Fuchs corneal endothelial dystrophy type 4 (FECD4), both characterized by corneal endothelial cell (CEnC) dysfunction and/or cell loss leading to corneal edema and visual impairment. In this study, we characterize the impact of CHED-/FECD4-associated SLC4A11 mutations on CEnC function and SLC4A11 protein localization by generating and comparing human CEnC (hCEnC) lines expressing wild type SLC4A11 (SLC4A11WT) or mutant SLC4A11 harboring CHED-/FECD4-associated SLC4A11 mutations (SLC4A11MU). SLC4A11WT and SLC4A11MU hCEnC lines were generated to express either SLC4A11 variant 2 (V2WT and V2MU) or variant 3 (V3WT and V3MU), the two major variants expressed in ex vivo hCEnC. Functional assays were performed to assess cell barrier, proliferation, viability, migration, and NH3-induced membrane conductance. We demonstrate SLC4A11-/- and SLC4A11MU hCEnC lines exhibited increased migration rates, altered proliferation and decreased cell viability compared to SLC4A11WT hCEnC. Additionally, SLC4A11-/- hCEnC demonstrated decreased cell-substrate adhesion and membrane capacitances compared to SLC4A11WT hCEnC. Induction with 10mM NH4Cl led SLC4A11WT hCEnC to depolarize; conversely, SLC4A11-/- hCEnC hyperpolarized and the majority of SLC4A11MU hCEnC either hyperpolarized or had minimal membrane potential changes following NH4Cl induction. Immunostaining of primary hCEnC and SLC4A11WT hCEnC lines for SLC4A11 demonstrated predominately plasma membrane staining with poor or partial colocalization with mitochondrial marker COX4 within a subset of punctate subcellular structures. Overall, our findings suggest CHED-associated SLC4A11 mutations likely lead to hCEnC dysfunction, and ultimately CHED, by interfering with cell migration, proliferation, viability, membrane conductance, barrier function, and/or cell surface localization of the SLC4A11 protein in hCEnC. Additionally, based on their similar subcellular localization and exhibiting similar cell functional profiles, protein isoforms encoded by SLC4A11 variant 2 and variant 3 likely have highly overlapping functional roles in hCEnC.

The purpose of this study was to explore the pathogenicity and function of two novel SLC4A11 variants associated with congenital hereditary endothelial dystrophy (CHED) and to study the function of a SLC4A11 (K263R) mutant in vitro. Ophthalmic examinations were performed on a 28-year-old male proband with CHED. Whole-exome and Sanger sequencing were applied for mutation screening. Bioinformatics and pathogenicity analysis were performed. HEK293T cells were transfected with the plasmids of empty vector, wild-type SLC4A11, and SLC4A11 (K263R) mutant. The transfected cells were treated with SkQ1. Oxygen consumption, cellular reactive oxygen species (ROS) level, mitochondrial membrane potential, and apoptosis rate were measured. The proband had poor visual acuity with nystagmus since childhood. Corneal foggy opacity was evident in both eyes. Two novel SLC4A11 variants were detected. Sanger sequencing showed that the proband's father and sister carried c.1464-1G>T variant, and the proband's mother and sister carried c.788A>G (p.Lys263Arg) variant. Based on the American College of Medical Genetics (ACMG) guidelines, SLC4A11 c.1464-1G>T was pathogenic, whereas c.788A>G, p.K263R was a variant of undetermined significance. In vitro, SLC4A11 (K263R) variant increased ROS level and apoptosis rate. Decrease in mitochondrial membrane potential and oxygen consumption rate were remarkable. Furthermore, SkQ1 decreased ROS levels and apoptosis rate but increased mitochondrial membrane potential in the transfected cells. Two novel heterozygous pathogenic variants of the SLC4A11 gene were identified in a family with CHED. The missense variant SLC4A11 (K263R) caused mitochondrial dysfunction and increased apoptosis in mutant transfected cells. In addition, SkQ1 presented a protective effect suggesting the anti-oxidant might be a novel therapeutic drug. This study verified the pathogenicity of 2 novel variants in the SLC4A11 gene in a CHED family and found an anti-oxidant might be a new drug. Corneal dystrophy (CD) is most recently defined as a collection of rare hereditary non-inflammatory disorders of abnormal deposition of substances in the cornea. CD was coined in 1890 by Arthur Groenouw and Hugo Biber, and the efforts of Ernst Fuchs, Wilhelm Uhthoff, and Yoshiharu Yoshida solidified the foundation of the understanding of these diseases. As proposed in 2015 by the International Classification of Corneal Dystrophies (IC3D), CD is sub-classified by the anatomic location affected: epithelial/subepithelial, epithelial-stromal, stromal, and endothelial dystrophies. Discoveries and unique case studies continue to broaden our understanding and classification of these diseases; therefore, it is difficult to categorize every single dystrophy solely into these four major labels.   The objective of this article is to present an overview of the evaluation and management for the most prominent and understood variants of CD. Highlights of these dystrophies will be discussed. However, further in-depth discussion on these dystrophies will be in separate StatPearls articles.  Patients with CD can be asymptomatic, but if symptoms occur, they typically experience bilateral visual acuity loss, typically in the form of irregular astigmatism. Depending on the corneal layer affected, patients may also manifest with photophobia, dry eyes, corneal edema, and recurrent corneal erosions, especially with epithelial-based CD, which causes considerable pain. Symptoms can begin at any age, depending on the diagnosis. Treatment can range from conservative measures to corneal transplantation.   CD is a significant but rare ocular disease. The genetic component of this disease is important for patients to understand, especially for affected patients involved with family planning. As we begin to understand genetics in greater detail, better evaluation and treatments for CD will come to fruition.  The objective of this article is to present an overview of the general evaluation and management for the most prominent and understood variants of CD. Highlights of these dystrophies will be covered, but the author intends to elaborate on these dystrophies separately in other StatPearls articles. The variants of CD based on their new anatomic classifications in IC3D are:  Epithelial and subepithelial dystrophies  : Epithelial basement membrane corneal dystrophy (EBMCD), also previously known as map-finger-dot dystrophy, Cogan microcystic dystrophy, and anterior basement membrane dystrophy. . Epithelial recurrent erosion dystrophies (EREDs) which includes Franceschetti corneal dystrophy, dystrophia smolandiensis, and dystrophia helsinglandica . Subepithelial mucinous corneal dystrophy (SMCD) . Meesmann corneal dystrophy (MECD) also known as juvenile epithelial corneal dystrophy . Lisch epithelial corneal dystrophy (LECD) . Gelatinous drop-like corneal dystrophy (GDLD) . Epithelial-Stromal Dystrophies (still included under epithelial and subepithelial dystrophies) : Lattice corneal dystrophy (LCD), with its subtypes: type I (TGFBI mutation) and type II (familial amyloidosis Finnish type), including LCD variants . Granular corneal dystrophy (GCD), types I and II (Avellino-type)  . Reis-Bückler’s corneal dystrophy (RBCD) . Thiel-Behnke corneal dystrophy (honeycomb dystrophy) (TBCD) . Stromal dystrophies: Macular corneal dystrophy (MCD)  . Schnyder corneal dystrophy (SCD)  . Congenital stromal corneal dystrophy (CSCD)  . Fleck corneal dystrophy (FCD)  . Posterior amorphous corneal dystrophy (PACD)  . Pre-Descemet corneal dystrophy (PDCD)  . Central cloudy dystrophy of francois (CCDF) . Endothelial Corneal Dystrophies: Fuchs endothelial corneal dystrophy (FECD)  . Posterior polymorphous corneal dystrophy (PPCD)  . Congenital hereditary endothelial dystrophy (CHED)  . X-linked endothelial corneal dystrophy (XECD) .

To describe three anterior segment dysgenesis disorders with infantile corneal opacities, namely, congenital hereditary endothelial dystrophy (CHED), primary congenital glaucoma (PCG), and Peters anomaly (PA) in terms of clinical characteristics, histopathology, genetic association, and diagnostic imaging profiles using imaging modalities such as ultrasound biomicroscopy (UBM) and microscope-integrated intraoperative optical coherence tomography (i-OCT). Seventy-four eyes with 22 eyes of CHED, 28 eyes of PA, and 24 eyes of PCG were clinically evaluated and underwent imaging using UBM and i-OCT. Corneal buttons of 16 operated patients underwent histopathological analysis, while genetic analysis was done in 23 patients using whole-exome sequencing. Corneal diameters (CD) and UBM parameters like anterior chamber depth (ACD), iris thickness (IT), and ciliary body (CB) thickness revealed a statistically significant difference between the three categories. In PA, 9 eyes had a third rare phenotype with only a posterior corneal defect with no iris adhesions. Genetic mutations were seen in all tested patients with CHED, in 83.3% of patients with PCG, and in 80% of patients with the third type of PA. i-OCT helped in the characterization of corneal opacity, identification of posterior corneal defects, iridocorneal adhesions, and contour of Descemet's membrane. Overlapping phenotypes of the above disorders cause a diagnostic dilemma and parameters like CDs, UBM ACD, IT, and CB thickness help differentiate between them. i-OCT can help in classifying the diseases in a high resolution, non-contact manner, and can better delineate corneal characteristics. The rare third type of PA phenotype may have a genetic association.