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Autologous ex Vivo Conjunctival Epithelial Cell Expansion for Ocular Surface Transplantation

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00346450
Recruitment Status : Completed
First Posted : June 30, 2006
Last Update Posted : January 13, 2010
International Stem Cell Forum
National Medical Research Council (NMRC), Singapore
Singapore Eye Research Institute
Information provided by:
Singapore National Eye Centre

Brief Summary:
To evaluate the use of cultivated conjunctival epithelial equivalents for the treatment of ocular diseases

Condition or disease Intervention/treatment Phase
Pterygium Ocular Surface Disease Stevens Johnson Syndrome Chemical Injury Procedure: Cultivated conjunctival transplantation Phase 3

Detailed Description:

Ex-vivo autologous conjunctiva expansion on human amniotic membrane (HAM), followed by clinical transplantation surgery

Preparation of HAM. Human amniotic membrane (HAM) prepared for human use will be obtained from the Singapore Eye Bank. HAM will be rapidly thawed in a 37oC water bath, and washed with phosphate buffered saline. The amniotic epithelium will be removed using a combination of Dispase digestion and mechanical scraping. Complete removal of the amniotic epithelial cells will be confirmed by microscopy. The HAM is then placed on a culture plate, with the basement-membrane side up, and incubated with DMEM at 37oC in an atmosphere of 5% CO2 and 95% air overnight before use.

Ex-vivo expansion of conjunctival cells on HAM. A forniceal conjunctival biopsy will be performed in patients undergoing pterygium surgery. The tissue will be cultured on the HAM either as a cell suspension or as explants, with the methods described above. The media is changed every 2 days and the culture is maintained for 2-3 weeks. The cells will form a confluent sheet and begin to stratify and differentiate. The tissue will then be raised to an air-liquid interface to promote differentiation.

Histological analysis. The conjunctival epithelial cell sheets on the amniotic membrane will be examined by light microscopy. Samples of the tissue will be fixed and processed with the use of standard histological procedures and stained with H&E and PAS reagents. Electron microscopic examination will be carried for the tissue. The sections will also be subjected to immunohistochemical analysis for cytokeratin markers.

Clinical Transplantation of cultivated conjunctival epithelial cells on HAM

Preparation of cultivated conjunctival cells on amniotic membrane Patients with various ocular surface disorders will be selected for the initial series of transplantations. All patients will undergo full counselling for informed consent for the procedures. A forniceal conjunctival biopsy will be performed on the contralateral healthy eye. PI will perform the transplantations of autologous conjunctival sheet grown on human amniotic membrane in these patients. The diseased area will be excised using the standard surgical technique. The defect will be covered with the sheet of cultured conjunctival cells on the HAM with the epithelial side up. The graft is secured to the adjacent conjunctiva with interrupted 8/0 vicryl sutures. A planotherapeutic bandage contact lens is placed to protect the tissue from lid trauma. Topical steroid and antibiotic eyedrops will be administered daily to reduce the ocular inflammation. Survival of conjunctiva on the amniotic membrane will be closely monitored and patients will be followed-up at 3 monthly intervals up to one year. During these visits, these patients will have anterior segment photographs taken and fluorescein staining to monitor the progress of healing.

Transplantations may also be carried out on selected patients with ocular surface disease, for example, ocular cicatricial pemphigoid, Stevens Johnson syndrome and alkali injury. For these severe conditions, this procedure may prove to be an important adjunct to other procedures, such as limbal stem cell transplantation. If the initial study is successful, a randomised clinical trial comparing this procedure with conventional conjunctival autografting and conventional amniotic membrane transplantation will be planned. Therefore if found to be successful, transplantation of cultured conjunctival cells on HAM may eventually be used as a primary procedure or as an adjunctive procedure for these visually debilitating conditions.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 80 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Autologous ex Vivo Conjunctival Epithelial Cell Expansion for Ocular Surface
Study Start Date : October 2001
Actual Study Completion Date : December 2003

Primary Outcome Measures :
  1. Epithelialisation
  2. Graft integrity
  3. Resolution of inflammation
  4. Visual acuity
  5. Complications

Secondary Outcome Measures :
  1. Degree of scarring

Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Patients with ocular surface disorders, e.g. primary pterygium, scheduled for elective surgical excision
  2. Indications for surgery will be the presence of ocular surface symptoms in the affected eye, loss of visual acuity from visual axis obscuration or irregular astigmatism, or cosmesis.
  3. Only one eye of a patient will be eligible for study entry.
  4. Patients who are adult males and females who are aged 21 or older, and are considered mentally sound
  5. Patients who are willing to undergo long-term follow-up, as outlined in this protocol
  6. Patients who have signed an informed consent form that has been approved by the SNEC Ethics Committee.

Exclusion Criteria:

  1. Patients less than 21 years of age
  2. Patients who are incapable, either by law or of mental state, of giving consent in their own right
  3. Patients who are either unable or unwilling to keep scheduled appointments and adhere to the other aspects of the protocol
  4. Patients who are pregnant or breastfeeding
  5. Patients with a history of drug allergy
  6. Patients who have received an investigational drug within 28 days preceding surgery
  7. Patients with intraocular pressure over 21 mmHg or history of ocular hypertension or glaucoma
  8. Patients who are documented to be steroid responders

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00346450

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Singapore National Eye Centre
Singapore, Singapore, 168751
Sponsors and Collaborators
Singapore National Eye Centre
International Stem Cell Forum
National Medical Research Council (NMRC), Singapore
Singapore Eye Research Institute
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Principal Investigator: Leonard P Ang, FRCS SNEC, NUS
Principal Investigator: Donald T Tan, FRCS SNEC, SERI, NUS
Publications of Results:
Layout table for additonal information Identifier: NCT00346450    
Other Study ID Numbers: R198/24/2000
First Posted: June 30, 2006    Key Record Dates
Last Update Posted: January 13, 2010
Last Verified: January 2010
Keywords provided by Singapore National Eye Centre:
ocular surface
Additional relevant MeSH terms:
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Stevens-Johnson Syndrome
Conjunctival Diseases
Eye Diseases
Mouth Diseases
Stomatognathic Diseases
Drug Eruptions
Skin Diseases
Erythema Multiforme
Skin Diseases, Vesiculobullous
Drug Hypersensitivity
Immune System Diseases
Drug-Related Side Effects and Adverse Reactions
Chemically-Induced Disorders