Cornea is an outer transparent, convex layer of the eye. It is the part of the eye from where light rays enter the eye. Diseases of the cornea which reduce the transparency of the cornea hamper vision. It is responsible for majority of refractive power of the eye. Various diseases of eye can damage the cornea. In many corneal diseases, corneal transplant is required. In corneal transplant, patient’s diseased cornea is replaced by donor’s healthy cornea obtained from the eye bank. Corneal transplant is the most successful organ transplant in humans. Current use of Femtosecond laser to do corneal transplant has improved the outcomes significantly with better wound healing and early visual recovery.
Types of Corneal Transplant
- Full-thickness (Penetrating) Keratoplasty is used for many conditions that affect multiple layers of the cornea. In this, the entire cornea is replaced by the entire cornea of the patient. Donor cornea is secured with the help of stitches- 16 or 24 depending upon the size of the graft
- Endothelial Transplants such as Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK / DMEK) are used to treat conditions affecting primarily the back layer of the cornea (Descemets’ membrane and Corneal endothelium) such as Fuchs endothelial dystrophy and Bullous keratopathy. The advantage of this procedure is that it has lesser chances of graft rejection and lesser sutures are required in the surgery. Post operative surgical astigmatism is also minimal.
- Deep Anterior Lamellar Keratoplasty (DALK) can be done for conditions such as keratoconus and corneal stromal scar. In this patient’s anterior corneal stroma is replaced by donor’s corneal stroma. It also has lesser chances of rejection compared to penetrating keratoplasty.
Indications of Corneal Transplant
Clouding of the cornea
Non resolving Corneal ulcers
Cornea transplant is a relatively safe procedure. It also carries a small percentage of postoperative complications:
Eye infection or graft infection
Intraocular pressure rise or glaucoma
Rejection of the donor cornea
Utmost care is required after a corneal transplant.
What is Graft Rejection?
Graft rejection is a known complication of corneal transplant. As in corneal transplant donor cornea is used. Sometimes patients’ body doesn’t accept the corneal tissue and treats it as a foreign body and tries to get rid of it. Patient’s immune system starts working against the donor cornea which results in loss of transparency of the graft, called as graft rejection. Many a times if the patient reports to the treating corneal surgeon early, corneal graft rejection can be reversed with the help of medications. Some cases might not respond to the medical therapy and the graft eventually fails.
Signs of Graft Rejection of Infections are:
Sensitivity to light
Graft Infection, Is It Common?
Graft infection is not so common if post operative care is proper and medicines are put meticulously. All the post operative instructions should be followed. Since corneal transplant patient uses steroid eye drops for longer duration, there are chances of getting a fungal infection. Diabetic patient also has higher chances of getting a graft infection in the post operative period.
Post Operative Care
Like any other transplant that the human body undergoes, corneal transplant also requires utmost care. Few important things to keep in mind are:
Don’t splash water in the eyes
Protective eye glasses to be used for 1 month
Protect your eye from injury
Avoid heavy exercises
Regular follow up with the doctor is a must
Post-operative medicines will be prescribed by your cornea surgeon and they must be properly followed to attain optimal results. The number and duration of post-operative treatment depends on the reason for transplant. For example, a patient undergoing transplant for corneal infection or corneal ulcer will require oral and topical antibiotics for prolonged periods to prevent and recurrence of infection in the graft. The post-operative care must be discussed in detail with your cornea surgeon.
After complete healing of surgical site, all the sutures are removed. Suture removal is done in multiple sittings. After stitch removal, glasses are prescribed for better vision. Even after all the sutures have been removed, the few precautions have to be followed for increased graft survival. If we look at the visual outcomes of corneal transplant it varies from patient to patient and also upon pre-operative conditions and indication for surgery. Many a times the condition of the cornea is very poor and in those cases despite of a good surgical corneal transplant procedure the outcomes are not so good. Some corneal pathologies are notorious to reoccur like viral corneal ulcers, vascularised corneas, severe dry eye, repeated failed graft. In these cases chances of graft failure is high. It is always a better idea to discuss the pros and cons of corneal transplant with the corneal surgeon. No one can predict the exact outcome of the corneal transplant surgery but with the advanced techniques and better technology the outcomes of corneal transplant have improved significantly.
The cost of cornea transplant varies from hospital to hospital. For performing corneal transplant, the eye surgeon should be well trained in doing the surgery and in managing the patients in postoperative period. It is very important to use good quality cornea for corneal transplant. There are government approved eye bank which supplies the cornea to the HOTA Registered hospitals and also maintain the records of corneal tissue utilisation. Cornea should be properly evaluated for its quality and used accordingly. The blood sample of donor patient should also be checked by eye bank for serology and viral markers. Donor cornea should be stored in cornisol medium to avoid damage to the corneal tissue. Any change in colour of of the bottle containing corneal tissue should be discarded.
Bharti eye hospital is well equipped, NABH accredited eye hospital that has Human Organ Transplant Act (HOTA) permission from government of India for performing the cornea transplant. The cornea surgeons at Bharti Eye Hospital are specially trained in performing corneal transplant. This hospital is the best place to undergo corneal transplant. To know more call on 011 29240000