Corneal epithelium is a self-renewing tissue. Recent studies indicate that corneal epithelial stem cells reside preferentially in the basal layer of peripheral cornea in the limbal zone, rather than uniformly in the entire corneal epithelium. This idea is supported by a unique limbal/corneal expression pattern of the K3 keratin marker for corneal-type differentiation; the preferential distribut...

Lesions on the ocular surface can destroy the stem cells from the limbus and cause limbal stem cell deficiency. The limbal stem cell deficiency is marked by conjunctivalization, which can be defined as the invasion of conjunctival epithelium over the cornea. This process is accompanied by varying degrees of corneal changes such as neovascularization, inflammation, recurrent erosions, persistent...

OBJECTIVE To examine whether amniotic membrane transplantation (AMT), in preparing the perilimbal stroma, enhances the success of allograft limbal transplantation (ALT). METHODS Thirty-one eyes of 26 consecutive patients had cytologically proven limbal deficiency resulting from chemical burns (14 eyes); Stevens-Johnson syndrome, toxic epidermal necrolysis, or pseudopemphigoid (5 eyes); contac...

Introduction To evaluate the expression patterns of cytokeratin (K) 12, 13, and 19 in normal epithelium of the human ocular surface to determine whether K13 could be used as a marker for conjunctival epithelium. Methods: Total RNA was isolated from the human conjunctiva and central cornea. Those transcripts that had threefolds or higher expression levels in the conjunctiva than the cornea wer...

Background: Correlations between bone marrow, heart, kidney, liver, skin and lung transplant rejection or survival with human cytokine gene polymorphisms have been described. There are also reports about the role of cytokines and Tumor Necrosis Factors-Alpha (TNF-α) on corneal transplant in animal models. Further studies are needed to clarify the role of cytokines in corneal allograft rejection...

The effects of sclerocorneal limbal stem cell autograft transplantation in dogs with corneal wounds were studied. Eighteen dogs were divided in two groups (GI and GII). The animals of GI (n=12) underwent limbal transplantation 30 days after the destruction of limbal stem cells. The dogs of GII (n=6) only underwent destruction of stem cells (control group). Light microscopy examination of the ri...

PURPOSE To determine the correlation between the squamous metaplasia grade of the corneal surface and the clinical severity of the limbal deficiency in patients with this disorder. METHODS We studied 98 eyes of patients with limbal deficiency by impression cytology. These patients were divided into four groups in relation to their clinical severity: 14 eyes had no symptoms, 34 eyes showed a m...

Autophagy and macropinocytosis are processes that are vital for cellular homeostasis, and help cells respond to stress and take up large amounts of material, respectively. The limbal and corneal epithelia have the machinery necessary to carry out both processes; however, autophagy and macropinocytosis are relatively understudied in these two epithelia. In this Perspectives, we describe the basi...

PURPOSE To determine the expression patterns of the retinoblastoma protein and the E2F transcription factor families in limbal and corneal epithelia and in corneal keratocytes in situ during corneal development and differentiation. METHODS Retinoblastoma protein (pRb) and its family members p107 and p130; E2F-1, -2, and -4, members of the E2F family of transcription factors; and Ki67, a marke...

PURPOSE To investigate the etiology of corneal dysfunction in the Pax6(+/-) mouse model of aniridia-related keratopathy. METHODS Mosaic patterns of X-gal staining were compared in the corneal and limbal epithelia of female Pax6(+/-) and Pax6(+/+) littermates, age 3 to 28 weeks, hemizygous for an X-linked LacZ transgene, and Pax6(+/+), LacZ(-)<-->Pax6(+/+), LacZ(+) and Pax6(+/+), LacZ(-)<-->Pa...