Thursday 3 January 2013

CorneaCorneal Transplal CORNEAL                TRANSPLANTATIONnsp

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TRANSPLANT SURGERY…WHAT TO EXPECT:

 
Although only 20-25% of those with Keratoconus ultimately require corneal transplant surgery, for those who do, it is a crucial and sometimes worrisome decision. However, those who know what to expect before, during, and after surgery are better prepared and feel more in control of their eye care. 
side_bullet_but In Keratoconus, a corneal transplant is warranted when the cornea becomes unacceptably thin or when sufficient visual acuity to meet the individual's needs can no longer be achieved by contact lenses due to steepening of the cornea, scarring or lens intolerance. Lens intolerance occurs when the steepened, irregular cornea can no longer be fitted with a contact lens, or the patient cannot tolerate the lens.
 side_bullet_but Once the decision has been made, you will feel less anxious and more in control if you know what to expect and what the “normal” routine is for this type of surgery. The more information you have, the more prepared you will be.
 side_bullet_but It is a good idea to check with your insurance company prior to scheduling your surgery to check your coverage and any pre-authorization requirements. Ask specially about your post operative office visits, medicines, glasses and/or contact lenses.
 side_bullet_but A few days prior to surgery a general medical examination and routine laboratory tests (such as blood count and EKG) are done to ensure that you are fit enough to undergo surgery. You should not use aspirin for 2 weeks prior to surgery, since it tends to cause bleeding during surgery. Antibiotic drops are generally started one day before surgery to protect the eye from infection.
 side_bullet_but Do not eat or drink anything after midnight before the surgery (ask your doctor about taking prescribed medications on the day of the surgery).
In most cases, the surgery is done on an outpatient basis - you enter the hospital or surgery center a few hours prior to surgery and leave the same day- generally a few hours after the surgery. In the “pre-op” waiting area, you might be “prepped”- medication will be given to help you relax before surgery. A needle attached to tubing will be inserted to deliver fluids and medications into your vein and EKG leads will be attached to your chest in order to monitor your heart. These are standard safety precautions.
 side_bullet_but Local or general anesthesia can be used for this procedure. The decision as to which type is used should be discussed with your surgeon preoperatively and is based on your age, general health, length of surgery, your doctor's preference and your anxiety level.
 side_bullet_but In the operating room, your eyelids are carefully washed and covered with a sterile plastic drape. Oxygen is occasionally provided by a plastic tube placed near the nose. Patients often doze off during the operation, and most are left with vague recollections of a short procedure, although some remember all of it.
 side_bullet_but The entire procedure is done under a microscope. A circular cookie cutter-like instrument, called a trephine, is used to remove the center of the diseased cornea. A "button" is cut from the donor cornea. This donor tissue is then sewn in place with extremely fine nylon sutures.
 side_bullet_but At the conclusion of the procedure, a patch and shield are applied to protect the eye. You will then be taken to the recovery room , in case of general anaesthesia, to wait until you are fully awake before being discharged.
 side_bullet_but After surgery, you should rest the remainder of the day. Post surgical pain varies from person to person. Typically there is either no pain or only slight soreness for a few days which is usually relieved by painkillers. Discuss pain management with your surgeon before and after the surgery.
 side_bullet_but The eye drops are very important- be sure you know exactly when you should use them. Make your next appointment, usually in three to seven days. Be sure you know how to contact the doctor if there is a problem or you have any questions.
 side_bullet_but After the patch is removed, it is important to protect the eye from accidental bumps or pokes. Typically, for several months after surgery, patients wear glasses during the day and a plastic shield at night to protect the eye from trauma while sleeping. Since the new cornea is delicately sutured in place, a direct blow to the eye must be avoided. Contact sports are discouraged after corneal transplant. Otherwise, normal activity can be resumed within a few days. After the first day, shaving, brushing teeth, bathing, light housework, bending over, walking, reading, and watching TV will not hurt the eye.
 side_bullet_but Because the cornea has no blood supply, the transplant heals relatively slowly. Sutures are left in place for three months to one year, and in some cases if the vision is good, they are left in permanently. The sutures are buried and therefore don't cause discomfort. Occasionally, they do break and then need to be removed. Often they are removed, adjusted or loosened to improve vision. Suture adjustment and removal are simple, painless office procedures.
 side_bullet_but The sutures used in corneal transplants are made of a monofilament nylon and are quite small (22 microns - 1/3 the thickness of a human hair). There are many different suturing patterns used by surgeons the world over. All of these suture techniques are effective. Some are utilized because of the surgeon's preference and training. Other suturing techniques are employed depending on the specific problem for which the transplant is being done. In some cases, surgeons will use 16 individual ("interrupted") sutures; others use a continuous ("running") suture, which is much like a hemstitch. Still others routinely use a combination of both types. In all cases, the results are more or less equivalent.
 side_bullet_but Vision gradually improves as the new cornea heals. There is often useful vision within a few weeks. However, in some cases, it may take several months to a year for good visual acuity.
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To prevent rejection of the new cornea, steroid eye drops are used for several months after surgery. In some cases, low dosage steroid drops are continued indefinitely. Unlike oral steroids, steroid eye drops cause no side effects elsewhere in the body. Occasionally, other eye medications are necessary.
 side_bullet_but It is important to call immediately (including weekends, evenings, and holidays) if you notice any unusual symptoms, including Redness, Sensitivity to lights, Vision loss, or Pain ("RSVP"). Flashing lights, floaters, and loss of peripheral vision should also be reported immediately.
 side_bullet_but Postoperative care is extremely important and by far the most time-consuming part of having a corneal transplant. The eye is checked the day after surgery, several times in the first two weeks, at gradually longer intervals over the first year, and usually yearly thereafter.
side_bullet_but There is every reason to believe your graft will succeed and last a lifetime. With proper care and prompt attention to any signs of rejection the graft will remain clear and healthy.
Vision after a Corneal Transplant:side_bullet_2
 
Vision varies a great deal after a transplant and continues to change for many months. It may start out very poor and gradually improve or be very good immediately after surgery and then worsen. It could take up to a year to develop good, stable vision.

The more severe the keratoconus is, the more likely it is to see a dramatic improvement immediately after surgery. This is due to the dramatic change that occurs when the bulging and distorted cone is replaced with a new smooth donor graft. While some patients develop good vision while the sutures are still in place, best, most stable vision usually occurs after all the sutures are removed. Suture removal occurs at different times for different patients. It depends on the rate of healing, which is faster in younger people. The majority of keratoconus patients have their sutures removed 6-12 months after surgery.

An important question is the level of uncorrected vision that can be expected after surgery. Will glasses be an option, or will contact lenses still be needed? A small percentage of transplant patients do obtain uncorrected vision good enough that neither glasses nor contacts are needed after surgery, but in the majority of cases, some form of vision correction is needed after surgery. Although vision may not be perfect after surgery, it is nearly always a lot better than it was before.
Our consultants have considerable expertise in various lamellar surgeries like DSEK, DSAEK, DALK etc. DSEK (Descemet Stripping Endothelial Keratoplasty) and DSAEK (Descemet Stripping Automated Endothelial Keratoplasty) refers to a partial thickness corneal transplantation in which a small amount of stroma( a layer of the cornea) and the endothelium( the innermost part of the cornea) is transplanted to a decompensated cornea. DSEK/DSAEK is performed for corneal diseases like Fuch’s endothelial dystrophy, pseudophakic/aphakic corneal edema (corneal decompensation following cataract surgery) and any disorder in which the endothelium is dysfunctional.
Advantages of DSEK are manifold, making this the procedure of choice wherever indicated. The main advantage is the lack of sutures (used in traditional penetrating keratoplasty). Also, following DSEK, the visual recovery is more rapid and astigmatism (irregular shape of the cornea) is lesser.
DALK (Deep Anterior Lamellar Keratoplasty) refers to transplantation of only the top and middle layers of the cornea, leaving the innermost layer (endothelium) of the patient intact. The main advantages of this procedure is minimal/ nil chances of corneal endothelial rejection. DALK is increasingly being performed for keratoconus, other corneal diseases (scars) involving the top and middle portions of the cornea.
FEK ( Femtosecond laser Enabled Keratoplasty)  - The newest approach to corneal transplantation uses a femtosecond laser  - the same technology used for making flaps in LASIK surgery – to produce incisions in the cornea that enable the surgeon to exercise far more precision in what is removed, so that the transplanted tissue fits into the cornea like interlocking pieces of a puzzle. This dramatically reduces postoperative astigmatism because of the precision of the laser, and it strengthens the wound site, so that it is more resistant to traumatic opening in the event of eye injury following surgery.
The cornea surgeon would examine your cornea and suggest the surgical procedure of choice, that would be the best option in your case scenario.
The news is also good for patients with diseased cornea who are not candidates for transplantation using donor tissue. Instead, some of these patients may be candidates for an artificial cornea transplant.    

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