Corneal Transplant

Several decades ago, penetrating keratoplasty was a challenge to corneal surgeons. Constant effort by the corneal surgeon to improve the outcomes as well as utilization of the available resources has led to a revolutionary change in the field of keratoplasty. All these efforts have led to the evolution of techniques that allow a corneal surgeon to disease-specific transplant of individual layers of corneal "so-called component corneal surgery" depending on the layer of cornea affected. This has led to an improvement in corneal graft survival as well as a better utilization of corneal tissues...

Limbal stem cell defect model is an important animal model that provides a basis for the study of ocular surface diseases. The rabbit cornea is of moderate size and is widely used in such studies as an experimental animal model. At present, the main modeling methods are alkali burns, and corneal limbus girdling and corneal epithelium doctoring. Each method has its own characteristics. In this study, we observed rabbit models with severe ocular surface defect established by the two methods and changes after amniotic membrane transplantation...

The aim of the present study was to investigate the use and effectiveness of a selective, partial, pedunculated (tongue-shaped) conjunctival flap (CF) for the treatment of refractory fungal keratitis (FK) with or without perforation. A total of 31 cases of corneal diseases treated by CF surgery between April 2014 and October 2015 were evaluated. Among the 31 cases, 16 cases (male:female, 11:5) with FK were selected. Logistic regression analysis was used to investigate factors associated with complications of CF surgery...

Purpose: To explore the role and mechanism of bone marrow-derived mesenchymal stem cells (BM-MSCs) in corneal epithelial wound healing in type 1 diabetic mice. Methods: Diabetic mice were treated with subconjunctival injections of BM-MSCs or recombinant tumor necrosis factor-α-stimulated gene/protein-6 (TSG-6). The corneal epithelial wound healing rate was examined by fluorescein staining. The mRNA and protein expression levels of TSG-6 were measured by quantitative RT-PCR and Western blot...

BACKGROUND: Corneal pathology is one of the leading causes of preventable blindness in South Africa (SA). A corneal transplant can restore or significantly improve vision in most cases. However, in SA there is a gross shortage of corneal tissue available to ophthalmologists. Little has been published describing the magnitude of the problem. OBJECTIVES: To describe trends in the number of corneal donors per year in SA, the number of corneal transplants performed each year, the origin of donors, the allocation of corneas to the public or private sector, and the demographics of donors...

BACKGROUND: Kaposi's sarcoma (KS) is generally considered a neoplastic disorder of vascular origin and occurs in patients with acquired immunodeficiency syndrome (AIDS) or who have received immunosuppressive treatments after an organ transplant (Soulier et al., Blood 86(4):1276-80, 1995; Viejo-Borbolla and Schulz, AIDS Rev 5(4):222-9, 2003; Schulz, J Antimicrob Chemother 45(Suppl T3):15-27, 2000; Aversa et al. Crit Rev Oncol Hematol 53(3):253-65, 2005; Mbulaiteye and Engels, Int J Cancer 119(11):2685-91, 2006; Tessari et al...

Cellular blue nevus is an uncommon neoplasm in the conjunctiva. Here we present an unusual case of a cellular blue nevus that clinically resembled conjunctival melanoma. A 29-year-old Chinese male was found to have a giant pigmented lesion of the conjunctiva around the limbal area of right eye from birth. Excisional biopsy with no-touch technique, lamellar corneal transplantation, amniotic membrane transplantation and adjuvant cryotherapy were performed. Histopathology revealed a nodular, well-defined tumor, which was composed of heavily pigmented dendritic cells and less pigmented spindle cells...

Corneal neovascularization (CNV) is one of the leading causes of vision loss and a high-risk factor for transplant rejection. The present study proposed a supramolecular hydrogel comprised of MPEG-PCL micelles and α-cyclodextrin (α-CD) for co-delivery of dexamethasone sodium phosphate (Dexp) and Avastin(®) (Ava), and further evaluated its therapeutic efficacy in rat alkali burn model. A physical mixing of Dexp/Ava, MPEG-PCL micelles, and α-CD aqueous solution leads to a spontaneous formation of the supramolecular hydrogel via a "host-guest" recognition between MPEG and α-CD...

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Human corneal endothelium has long been thought to be a non-mitotic cell layer with no endogenous reparative potential. Pathologies that damage endothelial function result in corneal decompensation and, if untreated, blindness. The mainstay of treatment involves partial or complete corneal replacement, amounting to 40% of all corneal transplants performed worldwide. We summarize the case reports describing complications post-operatively in the form of (sub)total graft detachment and those resulting in post-operative bare stroma...

PURPOSE: Catquest-9SF is a 9-item visual disability questionnaire developed for evaluating patient-reported outcome measures after cataract surgery. The aim of this study was to use Rasch analysis to determine the responsiveness of Catquest-9SF for corneal transplant patients. METHODS: Patients who underwent corneal transplantation primarily to improve vision were included. One group (n = 199) completed the Catquest-9SF questionnaire before corneal transplantation and a second independent group (n = 199) completed the questionnaire 2 years after surgery...

PURPOSE: To assess the rejection episode rate after deep anterior lamellar keratoplasty (DALK) and to identify associated risk factors. METHODS: This retrospective review of 251 primary DALK procedures performed by 14 surgeons at a single center between February 2008 and November 2015 evaluated the rejection episode rate and associated risk factors using Kaplan-Meier survival and proportional hazards analyses, which took the length of follow-up into consideration...

PURPOSE: To evaluate the reliability between pneumatonometry intraocular pressure (IOP) measurement in different scleral locations and corneal IOP in a penetrating keratoplasty (PK) setting. Our aim is to validate a method that can potentially be used for patients with keratoprostheses. METHODS: This is a prospective observational study of 40 patients who underwent monocular PK by a single surgeon and had no significant anterior segment condition in the contralateral eye...

Lymphangiogenesis is essential for fluid homeostasis in vascularized tissues. In the normally avascular cornea, however, pathological lymphangiogenesis mediates diseases like corneal transplant rejection, dry eye disease, and allergy. So far, a physiological role for lymphangiogenesis in a primarily avascular site such as the cornea has not been described. Using a mouse model of perforating corneal injury that causes acute and severe fluid accumulation in the cornea, we show that lymphatics transiently and selectively invade the cornea and regulate the resolution of corneal edema...

PURPOSE: To report the adverse event of topical tosufloxacin administered after penetrating keratoplasty in one patient. CASE REPORT: A 60-year-old female was referred to our hospital for treatment of vision loss due to corneal opacification, etiology was unknown. Slit lamp examination showed dense opacification in corneal stroma. Penetrating keratoplasty was performed on her left eye. She was treated with topical applications of 1.5% levofloxacin, 0.5% cefmenoxime, 0...

We summarize up-to-date diagnostic and treatment of infectious keratitis using literature data and some clinical examples. In the clinical practice, most commonly bacterial, herpetic, mycotic and acanthamoeba keratitis occur. Beside slitlamp examination, for diagnostic purpose, we analyse corneal sensitivity, perform in vivo confocal microscopy, polymerase-chain-reaction (PCR), in vitro culture and histological examination of the corneal sample. As conservative treatment we use primarily topical moxifloxacin or cephasolin with fortified tobramycin or gentamycin in bacterial, topical antiviral gel (in some cases in combination with systemic antiviral treatment) in part in combination with topical corticosteroids in herpetic, voriconasole or amphotericin-B in mycotic, and topical-triple-therapy (diamidine, biguanid and antibiotics) in acanthamoeba keratitis...

Limbal stem cells are responsible for the continuous renewal of the corneal epithelium. The destruction or dysfunction of these stem cells or their niche induces limbal stem cell deficiency (LSCD) leading to visual loss, chronic pain, and inflammation of the ocular surface. To restore the ocular surface in cases of bilateral LSCD, an extraocular source of stem cells is needed to avoid dependence on allogeneic limbal stem cells that are difficult to obtain, isolate, and culture. The aim of this work was to test the tolerance and the efficacy of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) to regenerate the ocular surface in two experimental models of LSCD that closely resemble the different severity grades of the human pathology...

This chapter provides a clinical perspective on the challenges that stand between current clinical practice and a cure for hepatorenal tyrosinemia (HT1). HT1 has been transformed in the last 50 years from an aggressive often undiagnosed childhood disease causing liver failure or liver cancer, with infant death in most patients, to a condition that is detectable at birth, and for which treatment with nitisinone (NTBC) and diet can prevent detectable liver or kidney abnormalities. What challenges remain? The properties of the affected metabolic pathway and the broad spectrum of severity seen in untreated patients are incompletely understood but potentially important for patients...

Fuchs endothelial corneal dystrophy (FECD) is a slowly progressive bilateral disease of corneal endothelium in which accumulation of extracellular matrix (ECM) and loss of corneal endothelial cells (CECs) are phenotypic features. The corneal endothelium maintains corneal transparency by regulating water hydration; consequently, corneal endothelial dysfunction causes serious vision loss. The only therapy for corneal haziness due to corneal endothelial diseases, including FECD, is corneal transplantation using donor corneas, and no pharmaceutical treatment is available...

Corneal wound healing is a complex process that occurs in response to various injuries and commonly used refractive surgery. It is a significant clinical problem, which may lead to serious complications due to either incomplete (epithelial) or excessive (stromal) healing. Epithelial stem cells clearly play a role in this process, whereas the contribution of stromal and endothelial progenitors is less well studied. The available evidence on stem cell participation in corneal wound healing is reviewed, together with the data on the use of corneal and non-corneal stem cells to facilitate this process in diseased or postsurgical conditions...