The cornea is the entrance of the light into the eye. It passes the light rays to the lens which converges them onto the retina. The cornea consists of several layers to provide protection and a clear image. A healthy, smooth, and clear cornea is essential for having a clear vision. It is because a scarred, injured and swollen cornea cannot pass and focus the light and leads to a blurry or glared vision. If the corneal tissue cannot repair on its own or by using medications, you may be recommended to undergo corneal implant (or graft) surgery. In this operation, the damaged cornea is replaced with a donated healthy human cornea.
The donors are the people who choose to donate their cornea after their death. The cornea is carefully checked to ensure it is healthy for implantation.
There are 5 techniques that surgeons use for corneal transplantation:
1.DALK (Deep Anterior Lamellar Keratoplasty)
When the under layers of cornea aren’t affected by the disorders such as keratoconus or trauma and injury, this operation is performed.
- First, the surgeon separates the thin outer layers of the cornea from the thicker middle layers by injecting air. Then, only the lifted layers are replaced.
- The quality criteria for this operation aren’t as strict as full-thickness transplant operation. The risk of damage to the lens and iris and infection inside the eyes is very low because the eye isn’t opened itself. In addition, the recovery and healing process is quicker.
2.DSEK or DSAEK (Descemet's stripping endothelial keratoplasty)
About half of the patients who undergo corneal transplant surgery have issues in the endothelium layer which is the innermost layer of the cornea.
- Fuchs’ dystrophy is one of the conditions that can be corrected with this surgery.
- During the procedure, the surgeon removes the endothelium layer along with the Descemet layer above it. Then it is replaced with the donated endothelium and Descemet layer attached to stroma for preventing damage to the new tissue caused by inappropriate handling.
In this surgery, the stroma layer isn't transplanted and the surgeon is harder because the donor tissue includes the endothelium and Descemet layer which are thin and fragile. However, the healing process takes less time compared to the DSEK technique.
4.PKP (Penetrating keratoplasty)
This technique is performed in the case of severe corneal scarring and stromal thinning.
In this procedure, an artificial cornea is used to replace the diseased cornea. The artificial cornea made of clear plastic has excellent optical properties and tissue tolerance. It is composed of three parts that are assembled in a collar-button shape. Then a hole is created on the host cornea by partial-thickness trephination and the full-thickness resection is completed using curved corneal scissors. Finally, the keratoprosthesis is sutured to the host tissue. Generally, keratoprosthesis is recommended to the patients who have multiple failed PKs.
- It is notable that Individual leaflets based on the patient/client plan will be offered to you including instructions before and after procedure and also for upcoming follow-up. During your staying in Iran, you will be fully supported by Exon English and Arabic translation team, who will be happy to assist with any concerns or queries that arise.
Up to 3 out of 10 patients may experience organ rejection. Organ rejection is the result of an immune system reaction to the foreign object that is the donor cornea. Rejection reaction has several signs including:
•Pain in the eye
•Hypersensitivity to the light
The rejection reaction may be stopped by using medications. Therefore, make sure to tell your doctor if you notice any of these signs. In the case of transplant rejection, you may need another surgery which has a higher risk of rejection compared to the first surgery.
A corneal transplant can cause other complications including:
•Retina detachment (pulling away of the tissue lining of the back of the eye)
•Glaucoma (hyper pressure in the eye)
Other eye problems such as glaucoma, macular degeneration, and diabetic retinopathy along with irregular curving of the new cornea could limit the vision. As a result, the vision may not be clear even if the outcome of the surgery is favorable.
Note: This package information is provided by the scientific team of Exon Health Paradise Co. and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.