Technique of cultivating limbal derived corneal epithelium on human amniotic membrane for clinical transplantation.

BACKGROUND: The technique of transplantation of cultivated limbal epithelium rather than direct limbal tissue isa novel method of "cell therapy" involved in reconstructing the ocular surface in severe limbal stem cell deficiency [LSCD], caused by chemical burns. AIM: To describe a simple feeder-cell free technique of cultivating limbal epithelium on human amniotic membrane[HAM]. MATERIALS AND METHODS: The limbal tissues (2 mm) were harvested from patients with LSCD. These tissues were proliferated in vitro on HAM supplemented by human corneal epithelial cell medium and autologous serum. Cultures covering more > or = 50% area of 2.5 x 5 cm HAM were considered adequate for clinical use. The cultured epithelium was characterized by histopathology and immunophenotyping. RESULTS: A total of 542 cultures out of 250 limbal tissues were cultivated in the laboratory from January 2001 through July 2005. The culture explants showed that clusters of cells emerging from the edge of the explants in one-three days formed a complete monolayer within 10-14 days. In 86% of cultures (464 of 542), the growth was observed within one-two days. Successful explant cultures were observed in 98.5% (534 of 542 cultures) with 91% explant cultures showing an area of > or = 6.25 cm2 (6.25 - 12.5 cm2 range). The cultivated epithelium was terminated between 10-14 days for clinical transplantation. The problems encountered were inadequate growth (2 of 542) and contamination (2 of 542). CONCLUSIONS: We demonstrate a simple technique of generating a sheet of corneal epithelium from a limbal biopsy. This new technique could pave the way for a novel form of cell therapy.

Spontaneous onset corneoscleral hematic cyst.

Corneoscleral cysts are a rare entity. We report a case of spontaneous corneoscleral hematic cyst, which was treated by cyst excision and lamellar corneal patch graft. No recurrence of cyst was noticed during the 6 years of followup.

New perspectives in ocular surface disorders. An integrated approach for diagnosis and management.

The cornea, conjuctiva and the limbus comprise the tissues at the ocular surface. All of them are covered by stratified, squamous, non-keratinizing epithelium and a stable tear film. The ocular surface health is ensured by intimate relationship between ocular surface epithelia and the preocular team film. There are two types of ocular surface failure. The first one is characterized by squamous metaplasia and loss of goblet cells and mucin expression. This is consistent with unstable tear film which is the hallmark of various dry-eye disorders. The second type of ocular surface failure is characterized by the replacement of the normal corneal epithelium in a process called limbal stem cell deficiency. It is essential to establish accurate diagnosis for appropriate management of complex ocular surface disorders. There has been considerable advancement in the understanding of the pathophysiology of ocular surface disease. Management has improved with introduction of the limbal stem cell concept and use of amniotic membrane transplantation.

Mooren's ulcer: current concepts in management.

Mooren's ulcer is strictly a peripheral ulcerative keratitis (PUK) with no associated scleritis. It occurs completely in absence of any diagnosable systemic disorder that could be responsible for the progressive destruction of the cornea. The aetiology of Mooren's ulcer remains uncertain. However, recent studies indicate that it is an autoimmune disease directed against a specific target molecule in the corneal stroma, probably triggered in genetically susceptible individuals by one of several possible provocateurs. Advances have been made in the management of this disease. Immunosuppressive therapy has been shown increasingly successful in patients unresponsive to conventional treatment and in bilateral progressive destructive ocular disease.