​Having already undergone two corneal transplant operations in his left eye over the last 10 years, Mr Chok Teck Chow was more than a little apprehensive about going through another one in his right eye.

"Previously, I needed 20 stitches and took six months to recover," said the 59-year-old who is semi-retired.

But he needn’t have worried. With an improved corneal transplant procedure offered at the Singapore National Eye Centre (SNEC), a member of the SingHealth group, he suffered only a few days of blurry vision. "By the fourth day, I could see well enough to go out by myself," he said.

The procedure, which is known as Descemet Membrane Endothelial Keratoplasty (DMEK), is a minimally invasive corneal transplantation. It involves transplanting a delicate sheet of corneal cells 1/100 mm thick, which is 10 times thinner than what was required in a previous commonly used procedure.

The cornea is the transparent, protective outer layer of the eye, and a transplant is the standard means of treatment in patients whose corneas are cloudy from ageing or disease.

Patient's original cornea is left mostly intact

With DMEK, the patient’s original cornea is left mostly intact, so it’s not immediately apparent that he’s had a transplant. It may also be possible for the patient to attain 100 per cent vision within a few weeks of surgery.

This sutureless technique was invented in Europe and first performed in Asia in September 2010.

A downside of the procedure is that it is an extremely difficult form of surgery. As the membrane transplanted is ultra thin and delicate, it tends to wrinkle into a tight roll when touched, potentially damaging the corneal cells when surgeons try to uncoil it.

To get around the problem, the team at the Singapore Eye Research Institute (SERI) developed a method that is safer and easier to perform, using the DMEK surgical insertion device.

Each year, about 350 corneal transplants are performed locally, of which about four in 10 involve patients with ageing corneas. With the ageing population, this number is expected to grow.

Ref: L20