PENETRATING CORNEAL TRANSPLANTATION

PENETRATING CORNEAL TRANSPLANTATION (MANUAL & FEMTOSECOND LASER)

The Human cornea is a dome shaped glass like transparent structure. Any injury infection or disease can turn it into a non-transparent structure. Such an event will prevent transmission and focusing of the light rays onto the retina making vision blurred. In order to restore the clarity, corneal transplantation (one of the most successful organ transplant) is done.

WHO NEEDS A CORNEA TRANSPLANT?

If there is irreversible loss of the normal corneal transparency either by trauma, infection, ocular surgery some drugs or glaucoma the cornea may need to be changed. Once the primary insult is arrested, a new cornea can structurally reconstruct the ocular systems clarity.

The cornea just like a glass has no blood supply and receives its nutrition from the fluids that bathe it internally and externally. Due to this property a corneal transplant is less likely to be rejected as compared to other organs such as kidney or heart etc. Additionally the technique has been improved and perfected and the post-operative protocols have been standardized to a great detail. We also know which cases have better prognosis and which ones are at high risk of failure allowing us to take special measures for such grafts.

Pre operative measures: It is essential that the primary insult is under control/inactive atleast for a period of 3 months before undertaking the surgery. Our Cornea Specialists will guide you as to what medications will improve the chance of success of the planned transplant

WHAT STEPS ARE DONE 

MANUAL TECHNIQUE AND FEMTOSECOND LASER KERATOPLASTY

Local anaesthesia makes the procedure pain free and the patient can remain awake during the procedure which lasts for ~1 hour or so

General anesthesia can also be given in children or very aged patients or those who are extremely comfortable being awake. 

A maximum of 80% of the central cornea is changed leaving behind 20% of the patient’s cornea. Special trephines are used to remove the diseased cornea and to cut a matching size of the donor cornea. Instead of manual trephines the same can be done with the help of Femtosecond Laser as well. 

Both the Donor and the patient corneas are cut by handheld trephines/suction trephines or Femtosecond laser.  An experienced surgeon can give excellent results with any of the three techniques. However laser corneal transplantation allows greater accuracy in cutting both the donor and recipient tissue.

The new cornea that has been thus cut is now attached to the patients eye using special sutures that are strong enough to support the new cornea and thin enough not to be seen. 

In complex cases with a coexisting cataract or glaucoma or retinal problem, additional surgery may be required at the time of the cornea transplant or after it. 

The new cornea slowly attaches itself to the patient’s eye. As this wound heals the stitches may become loose and necessitate removal. Your Cornea Specialist may also want to remove the stitches selectively to make the shape of the new cornea more regular as time goes by

Visual recovery is slow and at 3 months it may be possible to prescribe glasses to the patients. Subsequently as well the shape may keep changing until about a year after which you may discuss other options to improve vision, apart from spectacles with your Cornea specialist

DONOR CORNEA SELECTION AND UTILISATION

Donor Corneas that are used are only selected after a rigorous process. When the eyes are collected by an Eye Bank, the team also collects blood from the deceased donor. This blood is tested for HIV HBsAg and other diseases. Also a detailed enquiry of the patients existing diseases is noted. The Cornea itself is further subjected to examination on slit lamp and specular microscopy to assess for number density and health of the corneal cells.  Your Cornea Specialist will also assess the cornea and grade it into categories after through assessment and will only use a cornea best suited for your case.

COMPLICATIONS AND RISKS INVOLVED

Any Organ when transplanted is at a risk of being rejected by the host. This risk although least of all in the case of Cornea is atill a major threat to the graft. Patients must watch out for

R: Redness (unusual redness of the eye)

S: Sensitivity (increase in light sensitivity)

V: Vision (sudden change in vision clarity)

P: Pain (increase in eye pain)

Early diagnosis of an episode of rejection is useful as it can be successfully reversed with special medications

Other complications such as Infection in the graft, recurrence of the primary problem, secondary Glaucoma, suture related problems may arise and can be appropriately managed if found in the patient.

Post-operative care and Instructions:

GENERAL INSTRUCTIONS

1. Some redness discomfort and minimal watering are natural after any eye surgery.

2. In case of irritation/pain on application of eye drops –stop immediately and consult your eye doctor

3. Prolonged/indiscriminate use of any medication may cause damage to the eyes/optic  nerve/infections which may lead to irreversible blindness-PLEASE STOP YOUR MEDICATIONS AS GIVEN IN THE SCHEDULE

4. Keep the medicines in a cool and dry place protected from sunlight

5. Keep the cap of the bottle in a clean place, replace and tighten the screw  after every use 

6. Don’t touch/clean the nozzle of the bottle

7. Clean hands and dry them before application of drops

8. Pull the lower lid and apply 1 or 2 drops of the medicine

9. Close the eyes completely for atleast 5 minutes after application

10. Between applications of two eye medications, give a gap of 10 minutes at least.

11. Clean the eyes twice a day with sterile wipes or clean dry kerchief/ Ear buds soaked in antibiotic eye drops.

OR

You can boil water, soak cotton bolls in it, squeeze them and use to clean the eye/s

12. You can eat normal food/Diabetic diet as usual. 

13. Take all previous medicines as per your physician/Diabetologist/cardiologist etc

14. No Head bath for a week-you can take a bath from below your shoulders

15. Avoid TV/Screens etc for 2 days- after that you can watch the same as usual

16. Wear the protective glasses given to you after surgery at all times in the day. At night use the green colour shield as protection

17. No lifting of heavy weights/excessive exercise/weights/gym etc for 1 week

18. You can sleep on your back or on the side opposite the side of surgery. 

19. Do not bend repeatedly (for prayer or work ) for a month

20. Pranayam/light Yogasanas  can be safely resumed after a week of surgery( avoid kumbhak)

21. Avoid crowded places(malls/temples/etc) and long journeys for atleast 1 week

22. Travelling by flight after routine cataract surgery is permitted –discuss with your doctor if needed.

23. In case of any of the following please contact us immediately:-

• Sudden loss of vision
• Sudden development of Intense redness/pain/watering more than before
• . Discomfort with lights
• Sudden appearance of whiteness in eye