Alternatives to endokeratoplasty: an attempt towards reducing global demand of human donor corneas

Exploring single-cell RNA sequencing as a decision-making tool in the clinical management of Fuchs' endothelial corneal dystrophy

Single-cell RNA sequencing (scRNA-seq) has enabled the identification of novel gene signatures and cell heterogeneity in numerous tissues and diseases. Here we review the use of this technology for Fuchs' Endothelial Corneal Dystrophy (FECD). FECD is the most common indication for corneal endothelial transplantation worldwide. FECD is challenging to manage because it is genetically heterogenous, can be autosomal dominant or sporadic, and progress at different rates. Single-cell RNA sequencing has enabled the discovery of several FECD subtypes, each with associated gene signatures, and cell heterogeneity. Current FECD treatments are mainly surgical, with various Rho kinase (ROCK) inhibitors used to promote endothelial cell metabolism and proliferation following surgery. A range of emerging therapies for FECD including cell therapies, gene therapies, tissue engineered scaffolds, and pharmaceuticals are in preclinical and clinical trials. Unlike conventional disease management methods based on clinical presentations and family history, targeting FECD using scRNA-seq based precision-medicine has the potential to pinpoint the disease subtypes, mechanisms, stages, severities, and help clinicians in making the best decision for surgeries and the applications of therapeutics. In this review, we first discuss the feasibility and potential of using scRNA-seq in clinical diagnostics for FECD, highlight advances from the latest clinical treatments and emerging therapies for FECD, integrate scRNA-seq results and clinical notes from our FECD patients and discuss the potential of applying alternative therapies to manage these cases clinically.

ROCK Inhibitors in Corneal Diseases and Glaucoma-A Comprehensive Review of These Emerging Drugs

Rho kinase (ROCK) inhibitors have gained significant attention as emerging novel treatment options in the field of ophthalmology in recent years. The evidence supporting their efficacy in glaucoma and corneal pathology includes both in vitro and clinical studies. Among the available options, ripasudil and netarsudil have emerged as the leading ROCK inhibitors, and some countries have approved these therapeutic options as treatments for glaucoma. Various dosing regimens have been studied, including monotherapy and combination therapy, especially for patients with secondary glaucoma who are already on multiple medications. Another rising application of ROCK inhibitors includes their use as an adjunct in surgical procedures such as Descemetorhexis Without Endothelial Keratoplasty (DWEK), Descemet Stripping Only (DSO) to accelerate visual recovery, glaucoma surgeries to reduce scarring process and allow better intraocular pressure (IOP) control, or after complicated anterior segment surgery to treat corneal oedema. This article provides a comprehensive overview of the existing literature in the field, offering recommendations for prescribing ROCK inhibitors and also discussing patient selection, drug efficacy, and possible adverse effects.

Inhibiting miR-195-5p Induces Proliferation of Human Corneal Endothelial Cells

Transparency of the human cornea is responsible for clear vision, which is maintained by a monolayer of non-proliferative human corneal endothelial cells (HCEnCs). Dysfunction of these cells can result in irreversible corneal blindness. It is important to identify key factors that limit the proliferation of HCEnCs and thus attempt to reverse them. Extracellular vesicles contain cargo which includes microRNAs (miRNAs) that can modulate a cellular function. In non small cell lung cancer, expression of miR-195-5p has been shown to inhibit proliferation; therefore, we aimed to investigate the inhibitory effect of miR-195-5p in inducing the proliferation of HCEnCs. Human corneal endothelial cell line (HCEC-12) and primary HCEnCs were cultured with miR-195-5p scramble, mimic or inhibitor. Corneal tissues from human cadaveric and FECD donors, and from pigs, mice and rabbits, were used for RT-PCR. miR-195-5p showed an abundance value of 11,363.31 a.u. When normalized against HCEnCs from cadaveric donors, FECD tissues showed a significant upregulation of miR-195-5p (p < 0.05) but was significantly downregulated in pig (p < 0.001), mouse (p < 0.01) and rabbit (p < 0.001) CEnCs, which have known proliferative capacity. Proliferation, cell doubling, and wound healing rates were significantly higher when miR-195-5p was inhibited. Inhibiting miR-195-5p showed a significant improvement in viability (HEC staining), decreased cell apoptosis (TdT-dNTP staining) and expression of ZO-1, NA+/K+-ATPase and Ki-67 markers. Expression of miR-195-5p is found in HCEnCs and FECD cells, which restricts the proliferation of these cells. However, inhibiting miR-195-5p can induce the proliferation of HCEnCs, which opens exciting directions for future research in prolonging FECD pathogenesis by increasing the proliferative capacity of HCEnCs using anti-miR therapy in vivo.