PURPOSE Squamous metaplasia is a pathologic process that frequently occurs in nonkeratinized stratified ocular surface epithelia. The mechanism for this occurrence is largely unknown except for vitamin A deficiency. METHODS Human limbal explants were cultured under airlift with or without p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 or in a submerged manner for different dur...

CASE REPORT A 74-year-old man developed a partial limbal stem cell deficiency secondary to a chemical injury in the left eye. He was treated with a sectorial conjunctival epitheliectomy and amniotic membrane transplantation. After 3 weeks there was an intact, smooth and stable corneal epithelium. DISCUSSION This case report emphasizes that conjunctival epitheliectomy and amniotic membrane tra...

BACKGROUND & OBJECTIVE The limbus is enriched with the stem cells of corneal epithelium. Auto- and allograft limbal transplantations are effective in restoring the corneal epithelium and inhibiting inflammation and neovascularization. Preserved human amniotic membrane (AM) is now widely used as a substrate for ocular surface reconstruction. The combination of limbal and AM transplantation has b...

A severe keratitis can be produced after the direct injection of bacterial endotoxin, or lipopolysaccharide (LPS), in rabbits. Corneal inflammation can progress to scarring and vascularization within a 2 to 3 week period. Pretreatment with systemic adrenal corticosteroids (triamcinolone) prevents this response. Limbal cellular and vascular events were studied during the first 20 hr after inject...

Various approaches have been taken to improve our knowledge of the microenvironmental regulation of limbal epithelial stem cells. Researchers have extensively investigated the roles of growth factors, survival factors, cytokines, enzymes, and permeable molecules secreted by the limbal cells. However, recent evidence suggests that stem cell fate (i.e., self-renewal or differentiation) can also b...

A 60-year-old man with bilateral corneal opacity underwent cataract extraction surgery involving the use of a limbal relaxing incision in his left eye. He had lower lid ectropion and lagophthalmos in both eyes. Eleven days after the surgery, a slit-lamp examination revealed a neurotrophic corneal ulcer with a punch-out epithelial defect and rolled edges at the center of the pre-existing corneal...

The ocular surface consists of two distinct types of epithelial cells; conjunctival and corneal. Although anatomically continuous, these epithelia comprise two distinct cell populations. Corneal stem cells are located at the limbus. The microenvironment of the limbus is important in maintaining "stemness" of the stem cells and also acts as a barrier to conjunctival epithelial cells preventing t...

OBJECTIVE To describe the use of a single donor corneal tissue in 3 patients with corneal pathologic conditions. METHODS A donor corneal tissue was divided into 3 parts using a microkeratome and a trephine. The anterior lamellar disc was transplanted into a patient with macular corneal dystrophy using the automated lamellar therapeutic keratoplasty technique. The posterior lamellar disc was t...