diagnosis of corneal diseases is possible by measuring and evaluation of corneal thickness in different layers. thus, the need for precise segmentation of corneal layer boundaries is inevitable. obviously, manual segmentation is time‑consuming and imprecise. in this paper, the gaussian mixture model (gmm) is used for automatic segmentation of three clinically important corneal boundaries on opt...

still find it difficult to understand why the cornea expends metabolic energy to maintain its status quo. I suppose that one day we may know why the cornea is not a fixed and static structure, but meanwhile we slowly advance towards an understanding of the dynamic balances underpinning the superficial stasis of corneal transparency. The corneal stroma continuously strives to swell by imbibing f...

Hypoxia induced corneal swelling was observed and evaluated in healthy human volunteers by use of high speed, ultrahigh resolution optical coherence tomography (UHROCT). Two dimensional corneal images were acquired at a speed of 47,000 A-scans/s with 3μm x 10μm (axial x lateral) resolution in corneal tissue. The UHROCT tomograms showed clear visualization of all corneal layers, including the Bo...

Phacoemulsification and aspiration (PEA) has become the most popular cataract surgery, due to the establishment of safe surgical techniques and development of associated instruments. However, corneal endothelial damage still represents a serious complication, as excessive damage can lead to irreversible bullous keratopathy. In addition to causes such as mechanical or heat injuries, free radical...

Purpose To investigate the molecular basis of posterior polymorphous corneal dystrophy (PPCD) by examining the PPCD transcriptome and the effect of decreased ZEB1 expression on corneal endothelial cell (CEnC) gene expression. Methods Next-generation RNA sequencing (RNA-seq) analyses of corneal endothelium from two PPCD-affected individuals (one with PPCD3 and one of unknown genetic cause) com...

PURPOSE Although cryotherapy has long been used to eradicate corneal lesions, there have been no reports of adverse effects of cryotherapy on human corneas. We performed this study to evaluate and characterize ultrastructural damage to the human cornea following the transcorneal freezing-and-thawing procedure. METHODS Seven human donor corneas were randomly divided into three groups. 1, 2, an...

The corneal endothelium of four presumably normal human eyes, removed at operation, was studied toith the electron microscope. Thorotrast had been injected into the anterior chamber a few minutes prior to the enucleation. The Thorotrast particles reached the anterior end of the intercellular space within 3 minutes and had entered Descemet's membrane within 6.5 minutes after injection into the a...

purpose: to image leukocyte adherence to the vascular endothelium and extravasation into surrounding tissues in neovascularized corneas using acridine orange, a selective dna stain, in rats methods: corneal neovascularization was induced by placing two sutures in the cornea of one eye of 12 long-evans rats. one week later, acridine orange (4 mg/kg) was injected via the tail vein and the eyes we...

Following the application of needle, intraocular lens, freeze, and laser wounds to the center of discrete 1 cm2 areas, density-limited monolayers of cultured rabbit corneal endothelium demonstrate wound healing responses similar to those seen in in vivo corneas. The wounded monolayer reforms in a time period consistent with that seen in both in vivo and in vitro organ culture models, thus sugge...

To investigate the etiology of contact lens-induced transient endothelial changes (blebs) in the human cornea, the effects of five different stimuli on corneal thickness and the appearance of the corneal endothelium were assessed. The stimuli included: (1) a silicone contact lens; (2) a silicone contact lens in combination with anoxia; (3) anoxia alone; (4) a thick hydroxyethyl methacrylate (HE...