Cornea Disease Treatment & Transplantation

CORNEAL TRANSPLANT SURGERY

Corneal transplantation is a surgical operation in which donated healthy corneal tissue is used to replace a diseased cornea to restore vision. The cloudy cornea is first removed and a clear and healthy donor cornea is placed and stitched in place.

With the advancement in technology, there are other ways to replace a diseased or scarred cornea, compared to the common surgical approach like Penetrating Keratoplasty, which is also known as full-thickness corneal transplantation.

We specialise in the following types of cornea transplantation in Singapore:

  1. Lamellar (Partial) Keratoplasty
  2. Anterior Lamellar Keratoplasty
  3. Posterior Lamellar Keratoplasty / Endothelial Keratoplasty

1 / Lamellar (Partial) Keratoplasty

Lamellar (Partial) Keratoplasty refers to the replacement of selective parts of the cornea that are diseased, provided the disease has not extended to all the layers of the cornea.

Benefits of Lamellar (Partial) Keratoplasty

Lower risks of rejection and failure: Compared to the conventional surgical approach Penetrating Keratoplasty, there is longer graft survival and significantly lower risks of allograft rejection and failure in Lamellar (Partial) Keratoplasty refers procedures.

Better visual outcomes: There are less irregularity and astigmatism. Studies have also shown that Lamellar (Partial) Keratoplasty visual outcomes are comparable to those of Penetrating Keratoplasty .

2 / Anterior Lamellar Keratoplasty

Anterior Lamellar Keratoplasty is performed for those with diseases involving the upper portion of the cornea like:

  • Anterior scars
  • Anterior dystrophies
  • Keratoconus
  • Infectious keratitis
Benefits of Anterior Lamellar Keratoplasty

Lower risks of rejection and failure: Compared to the conventional surgical approach Penetrating Keratoplasty, there are significantly lower risks of allograft rejection and graft failure in Anterior Lamellar Keratoplasty procedures.

Better visual outcomes: There are less irregularity and astigmatism. Studies have also shown that Anterior Lamellar Keratoplasty visual outcomes are comparable to those of Penetrating Keratoplasty surgery.

Greater wound strength: Anterior Lamellar Keratoplasty is an extraocular procedure, which enables greater wound strength.

3 / Posterior Lamellar Keratoplasty/Endothelial Keratoplasty

In cornea diseases where the innermost layer of the cornea (endothelium) is affected, only the innermost layer of the cornea may be replaced.

Posterior Lamellar Keratoplasty/Endothelial Keratoplasty is performed for those with certain degenerative diseases like:

  • Fuch’s endothelial dystrophy
  • Bullous keratopathy

The surgery is performed through smaller incisions. The cornea graft can also be secured in place without the need for stitches. The new method is known as Descemet’s stripping automated endothelial keratoplasty (DSAEK).

Benefits of Posterior Lamellar Keratoplasty/Endothelial Keratoplasty

Better visual outcomes: There is less irregularity and astigmatism. Studies have also shown that Posterior Lamellar Keratoplasty/Endothelial Keratoplasty visual outcomes are comparable to those of Penetrating Keratoplasty surgery.

Faster visual recovery: There is less discomfort after Posterior Lamellar Keratoplasty/Endothelial Keratoplasty. Recovery is faster due to the use of semi-automated microkeratomes, which creates a smoother dissection plane, reduces interface irregularity, and improves the visual outcome.

No suture-related problems: As the donor graft is attached without sutures, there will not be any suture-related problems.

Greater wound strength: Posterior Lamellar Keratoplasty/Endothelial Keratoplasty is a minimally invasive cornea transplant procedure so there is greater wound strength.

If a significant cataract (cloudy lens) is present, the cataract may be removed at the time of the corneal transplant operation and an intraocular lens is implanted.

In most instances, first-time corneal transplants may be performed without the need for oral immunosuppression, and only eyedrop medication is required. Unlike other forms of organ transplantation, corneal transplantation may be repeated several times if previous transplants have failed. However, the success rate of repeat transplants becomes lower with each transplant and anti-rejection tablets may be required to prevent graft rejection in the subsequent transplants.

ARTIFICIAL CORNEA TRANSPLANT

In eyes which have had repeated corneal transplants that have failed or in eyes with complex cornea and ocular surface disorders, an alternative treatment is an artificial corneal transplant. The most established artificial corneal transplant in the world today is the Boston Keratoprosthesis.

Boston Keratoprosthesis (KPro)

An artificial cornea transplant is the replacement of a diseased or scarred cornea with a donor cornea. Made of clear plastic with tissue tolerance and optical properties, the Boston KPro is an artificial cornea. Boston KPro is a new and improved method for treating blinding cornea disease. Even the most complex corneal diseases can now be successfully treated with the Boston KPro.

Benefits of Boston KPro

Most established artificial cornea implant in the world: The Boston KPro can effectively restore vision in those with severe blinding corneal diseases, including those with high-risk corneal grafts and where previous corneal transplants and treatment have failed.

In severe blinding corneal diseases, the Boston KPro implantation may be the best option for restoring long-term vision in these patients

OUR EXPERIENCE

Dr Leonard Ang is known internationally for his extensive experience in treating a whole spectrum of cornea diseases, including complex blinding cornea diseases.

Dr Ang is among a small group of eye surgeons in Singapore to have trained in cornea and refractive surgery at prestigious eye centres around the world, including the University of Pennsylvania School of Medicine in USA, Kyoto Prefectural University of Medicine in Japan, and Harvard Medical School, Massachusetts Eye and Ear Infirmary in USA.

He underwent specialised training at the Harvard Medical School in artificial cornea transplantation (Boston keratoprosthesis). He performed the earliest series of Boston keratoprosthesis transplantations in Singapore and South East Asia and has helped to restore the vision of many local and international patients with complex cornea diseases. He also performed the earliest series of Paediatric Boston keratoprosthesis transplantations in Singapore and South East Asia for blinding childhood cornea diseases.

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