Reason of Corneal Transplant
The cornea is composed of a clear tissue layers covering the eye surface, similar to a watch crystal. A corneal transplant is performed to restore functional vision if the cornea has become cloudy or opaque due to a disease, scar, infection, swelling or chemical burn.
A graft replaces central corneal tissue, damaged due to disease or eye injury, with healthy corneal tissue donated from a local eye bank. An unhealthy cornea affects your vision by scattering or distorting light and causing glare and blurred vision. A cornea transplant may be necessary to restore your functional vision.
Corneal eye disease is the fourth most common cause of blindness (after cataracts, glaucoma and age-related macular degeneration) and affects more than 10 million people worldwide.
There are three main types of cornea transplants
- Traditional, full thickness cornea transplant also known as penetrating keratoplasty
- Front layer corneal transplant known as DALK
- Back layer cornea transplant known as endothelial keratoplasty
During penetrating keratoplasty, a circular button-shaped, full-thickness section of tissue is removed from the diseased or injured cornea using either a surgical cutting instrument called a trephine or a femtosecond laser
A matching “button” from the donor tissue is then positioned and sutured into place. The sutures (stitches) remain in place typically for a year or more after surgery.
Deep anterior lamellar keratoplasty (dalk)
It is a Surgical procedure done to remove the corneal stroma down to Descemet’s membrane. It is performed to treat a corneal disease where the endothelium is still functioning normally. The procedure offers advantages over penetrating keratoplasty (PKP), including a “closed-system” operation and a decreased risk of postoperative immune rejection.
Descemet’s Stripping Endothelial Keratoplasty ( DSEK)
It is a type of corneal transplant procedure where only the back layer of the cornea (endothelium) is transplanted.
Endothelial keratoplasty selectively replaces only the innermost layer of the cornea (endothelium) and leaves the overlying healthy corneal tissue intact.
The surgeon makes a tiny incision and places a thin disc of donor tissue containing a healthy endothelial cell layer on the back surface of your cornea. An air bubble is used to position the new endothelial layer into place. The small incision is self-sealing and typically no sutures are required.
Endothelial keratoplasty has several advantages over full-thickness penetrating keratoplasty. These include: faster recovery of vision; less operating time; minimal removal of corneal tissue and therefore less impact on the structural integrity of the eye and less susceptibility to injury; no related suture complications; and reduced risk of astigmatism after surgery.