SPONSORED FEATURE

B y D r V anitha H em a R atnalingam , P ark C ity Medical C entre

The cornea is the outermost layer of the eye . A healthy cornea allows light to enter the eye and focuses the light rays onto the retina . When the cornea is damaged , a cornea transplant may be necessary to restore vision .

What is a cornea transplant A cornea transplant is an operation where diseased or damaged cornea tissue is replaced with healthy donor tissue . This operation is also known as “ keratoplasty ”. Conditions that can be treated with a cornea transplant include :

• Corneal scarring from previous injury or infection

• Thinning of the cornea which causes it to lose its normal shape ( e . g . Keratoconus )

• Cloudiness of the cornea caused by endothelial cell loss ( e . g . Fuch ’ s endothelial dystrophy , intraoperative trauma )

Different types of corneal transplant surgery There are two surgical options for cornea transplantation : 1 . Penetrating Keratoplasty This is also known as a full thickness cornea transplant . It involves removing the entire thickness of the damaged cornea and replacing it with healthy donor tissue cut out into the same size and shape .

2 . Lamellar keratoplasty Lamellar keratoplasty is an operation in which the diseased layers are removed and replaced leaving in place the patients own healthy tissue . This type of surgery includes anterior lamellar keratoplasty or endothelial keratoplasty . In the former , the anterior or outer layers of the cornea are transplanted and

the healthy inner layers left intact . On the other hand , endothelial keratoplasty involves transplanting the inner corneal layers while retaining the healthy outer layers The advantages of lamellar keratoplasty include a reduced risk of rejection and a stronger eye .

Risks of cornea transplant In uncomplicated cases the success rate of a firsttime cornea transplant is 90 %. However , overtime the survival rate drops to 74 % at 5 year and and 62 % by 10 years . Rejection can occur in up to 10 % of cornea transplants . This happens when your immune system recognizes the donated cornea as foreign tissue and attacks it . This can be treated with steroid eyedrops if picked up early . Symptoms of graft rejection include the following Redness Sensitivity to light Vision becomes blur Pain

Other complications include infection , bleeding , pressure increase within the eyeball and problems with the stitches used to secure the cornea

Dr Vanitha Hema Ratnalingam ( Consultant Ophthalmologist and Corneal Surgeon )

Finding a donor cornea Corneas used in transplants come from people who have died . Unlike other organs transplants such as kidneys and liver , cornea transplants do not require tissue matching . All donors are screened for infectious diseases and their corneas screened thoroughly before being deemed suitable for a transplant . In Malaysia , the number of donors is low and inadequate to meet the needs of patients so , the majority of corneas used is imported from other countries .

GlobalHealthAsiaPacific . com ISSUE 6 | 2023

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