| The ocular surface comprises the corneal epithelium and the conjunctival epithelium covering the cornea and front surface of the eye. Ocular Surface Diseases (OSD) are the result of injuries to or cell deficiency of the corneal epithelium and conjunctival epithelium, causing blindness. Direct causes include chemical and thermal burns, trachoma and Stevens Johnson syndrome. |
Surgical view: cultured sheet of conjunctiva about to be transplanted onto the eye after excision of the pterygium
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Pterygium - Before and after surgery |
Previously, treating OSD with conventional corneal transplants was not very successful because the Limbal Stem Cells (source of healthy corneal epithelium) and Conjunctival Stem Cells were not being transplanted at the same time.
Thanks to pioneering methods and new surgical techniques, transplanting both Limbal and Conjunctival Stem Cells is now part of the procedure, contributing to the success of the corneal transplant in cases of OSD. To prevent rejection, patient's own limbal and conjunctival stem cells are cultured in SNEC's own SERI Stem Cell Laboratory and these cells are retransplanted back into the patient's own eye after 2 weeks. With this method, transplant rejection is avoided and success rates are far higher than using stem cells from other donors.
Singapore National Eye Centre (SNEC)
Leading International Centre
SNEC is one of only a handful of eye centres in the world offering cultured limbal stem cell transplants, and is the leading centre in the world culturing and transplanting conjunctival stem cells. Cultured limbal and conjunctival stem cell transplants are used to treat patients blinded by ocular surface diseases with damaged or deficient stem cells. These patients range from those suffering from chemical injuries to cancer to blindness due to generalised stem cell deficiency.
World's First
In October 2001, SNEC surgeons performed the first Cultured Conjunctival Stem Cell Transplant in a patient suffering from a common local conjunctival disorder known as pterygium. This surgery was believed to be the first of its kind in the world, as no one else was growing conjunctiva at that time.
High Success Rate
Since then, within a rigorous and ethically-approved clinical trial, a total of 22 patients with pterygium have received cultured stem cell transplants. In all cases, these transplants have been successful in resurfacing the eye after excision of the pterygium. We have since successfully performed autologous cultured conjunctival stem cell transplants in several other patients with a variety of other forms of ocular surface disorders such as ocular surface tumors and chemical burns.
Cutting-edge Treatment
This is a new technique of growing one's own stem cells (obtained from the fellow normal eye), which can be damaged by conditions such as chemical injuries, severe contact lens overwear and Steven's Johnson Syndrome (a severe allergic disorder affecting the eye). A small amount of tissue is taken from the healthy fellow eye, grown in the laboratory for 2-3 weeks and transplanted onto the damaged surface of the diseased eye.
For enquiries and appointments, please contact:
 Singapore National Eye Centre
International Patient Service
Tel: (65) 6100 9393 Fax: (65) 6222 9393
Email: ips@snec.com.sg
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Using Lamellar Keratoplasty to perform a cornea transplant - before and after operation |
Lamellar refers to lamellae, or layers (of the cornea). In certain instances, when the cornea is not diseased through its whole thickness, only the diseased portion, or layer, is partially dissected away, and a partial thickness donor cornea is placed. This is known as a Lamellar Keratoplasty (LK). This newer technique has fewer side effects, less risk of rejection and longer graft survival rates.
Due to the complexity of this procedure, only very few transplant centres offer this form of surgery, and SNEC is one of the few centres in the region performing this form of surgery. About 20% of transplants we perform are lamellar grafts.
Less commonly, corneal transplants can be done on an urgent basis to treat severe infections of the cornea, or to "patch up" severe thinning, defects or perforations in the cornea or sclera (white part of the eye) due to previous injury, inflammation or infections.
All corneal transplants require the patient to have a healthy nerve and retina in the back of the eye.
Singapore National Eye Centre (SNEC)
Depth of Experience
The SNEC Corneal Transplantation Programme works in close collaboration with the Singapore Eye Bank, which makes available a large number of high quality donor corneas each year for transplants. Under this programme, the SNEC performs over 150 transplants a year.
Advanced Techniques
We are also one of the leading transplant centres in the world that offers new advanced LK techniques, stem cell transplants and Osteo-Odonto Keratoprosthesis (OOKP) Surgery, a radical and probably the most complex eye operation today.
New Technologies
Our new technologies include human amniotic membrane transplantation, human ocular stem cell culturing and transplantation, and the development of the Artificial Cornea including the latest OOKP Surgery, commonly known as "tooth-in-eye" surgery and used for severe end-stage corneal diseases.
High Success Rate
Overall, the success rate of corneal transplants performed at SNEC exceeds 90%. Our success rate for a normal-routine transplant is about 90% in the first year (most complications, if any, occur within the first year of the transplant). The success rate for lamellar transplants are close to 100% due to the fact that transplantation rejection risks are virtually zero with this form of transplantation.
Internationally-accredited Eye Bank
All corneas transplanted at our centre are of excellent quality and come from Singapore Eye Bank (SEB), which get corneas from local donors and internationally-accredited eye banks in the US. The average wait for a donor cornea is one or two weeks. Donor corneas are available to Singaporeans and non-Singaporeans undergoing corneal transplants in Singapore.
For enquiries and appointments, please contact:
 Singapore National Eye Centre
International Patient Service
Tel: (65) 6100 9393 Fax: (65) 6222 9393
Email: ips@snec.com.sg
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