CORNEAL CARE

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The anterior segment of the eye includes the cornea, conjunctiva, sclera, upper and lower lids. The treatments range from medical to surgical. Medical and surgical management is offered for patients with disorders involving the front surface of the eye.

The following is a partial list of services we offer at Grendahl Eye Associates involving the cornea or clear window of the eye, the conjunctiva or lining inside the eyelids, and the sclera or white covering of the eye and eye lids.

Special services include:

• Corneal transplant surgery - replaces the central cornea with live donor tissue.
• Computerized corneal topography - precisely maps the curvature of the cornea.
• Pterygium removal - removes a scar-like growth on the surface of the eye.
• Treatment of infectious diseases of the eye's surface.
• Surgical treatment of corneal and conjunctival ulcers and other disorders.
• Corneal and scleral wound repairs - treats damaged cornea and scleral tissue.
• Treatment of dry eyes and blepharitis.
• Entropion and ectropion surgery - corrects eyelids that turn inward and outward.

A CORNEAL TRANSPLANT MAY RESTORE YOUR SIGHT

Transplants are the replacement of damaged or diseased tissue or organs with healthy tissue or organs. Ophthalmologists (medical and surgical eye doctors) perform over 40,000 corneal transplants each year in the United States. The cornea was one of the first parts of the body to be transplanted, and corneal transplants remain one of the most common - and most successful - of all transplant procedures including hearts, lungs, and kidneys.

During the procedure, part of a cloudy or warped cornea is replaced with a graft from a healthy cornea, which comes from an eye bank (see below). If the procedure is successful and the new cornea heals without problems, vision can be greatly improved.


WHAT IS THE CORNEA? A WINDOW TO THE EYE.

The Cornea is the front, outermost layer of the eye. Just as a window lets light into a room, the cornea is a clear "window" that lets light into the eye. The cornea also focuses the light as it passes through, helping make images clear and sharp, so we can see. To stay clear the cornea must be healthy.


WHAT IS AN EYE BANK?

Across the country, eye banks operate 24 hours a day to provide healthy replacement corneas for people who need transplants. The eye bank collects, evaluates, and stores donated corneas so they're available when needed. Corneas used in transplants are collected from recently deceased human donors. To protect the recipient of the cornea, the donor's cause of death and medical history are carefully screened. Blood tests are done to ensure that no contagious disease, such as AIDS or hepatitis, is present. The donated cornea may be used right away, or the eye bank may store it for a short period of time.


WHY DO YOU NEED A NEW CORNEA?

Corneal problems can make seeing difficult. A damaged cornea, like a frosted or warped windowpane, distorts light as it enters the eye. The cornea can be damaged by disease, injury, infection, previous eye surgery, or to other problems.



HOW CAN AN UNHEALTHY CORNEA AFFECT VISION?

If the cornea is damaged it may become swollen or scarred. In either case, its smoothness and clarity may be lost. The scars, swelling or an irregular shape cause the cornea to scatter or distort light, resulting in glare or blurred vision.

A corneal transplant is needed if:

• Vision cannot be corrected satisfactorily;
• Painful swelling cannot be relieved by medications or special contact lenses.

Following are seven common problems that may be treated with corneal transplants.

• The cornea may change shape, pushing outward like a cone. This disease is known as keratoconus. A cone-shaped cornea distorts light as it travels into the eye. You may see blurry or multiple images. Keratoconus mainly affects young adults; its cause is not known.
• After a LASIK procedure the cornea may push outward, bulging slightly, this is called progressive ectasia.
• The cornea may be affected by previous eye surgery for another problem. After eye surgery, such as cataract surgery, the cornea sometimes becomes swollen and cloudy. Consequently, you might experience glare or see images that are blurry, faint, or washed out. The swollen cornea may also develop painful blisters.

• The cornea may be injured by an eye infection, chemicals, fireworks, or a sharp object. This injury can create scar tissue, which is difficult for light to penetrate. You may see faint or distorted images, or only light and shadows.
• Hereditary corneal failure, such as Fuchs' dystrophy.
• Scarring after infections, especially after herpes.
• Rejection after first corneal transplant.

WHAT TO EXPECT

A corneal transplant won't change your natural eye color, because your iris isn't affected.

• It isn't necessary to find a cornea with a "matching" tissue or blood type. The race, gender, and eye color of the donor also don't matter.
• The cornea heals slowly, Full healing and vision improvement may take a year or more. The sutures are removed at one year or longer.
• It's difficult to shape the new cornea perfectly. So, astigmatism (a condition where the cornea has an irregular shape, making images look blurry or distorted) is common after a corneal transplant. In the past, it has been very difficult to correct the astigmatism in a graft, because it was quite high and many times irregular. We would use surgical techniques such as selective suture removal, relaxing incisions, and wedge resections. Now we have added a new surgical technique called LASIK done with the Excimer laser. With the advent of the LASIK procedure, we find it easier to correct the astigmatism if it is regular and the resulting myopia.

WHAT HAPPENS IF YOU DECIDE TO HAVE A CORNEAL TRANSPLANT?

BEFORE SURGERY

Once it has been determined that you need a corneal transplant, your name is put on a list at the local eye bank. Usually the wait is short. Your transplant procedure can be done when a donor cornea is available. The transplant may be scheduled right away, or your eye may be monitored for a while. Occasionally, a shortage of donated corneas may cause a scheduling delay. If both eyes need new corneas, the second transplant won't be done until the first eye has stabilized; this may be as long as a year.

The timing of your transplant depends on many factors, including the condition of your eye and the availability of a donor cornea. Before a cornea is released for transplant, the eye bank tests the human donor for the viruses that cause hepatitis and AIDS. The cornea is carefully checked for clarity.

You may need to have a physical examination and other special tests. If you usually take medications, you should continue them unless told otherwise. When the time arrives for your corneal transplant, you'll be instructed about how to prepare for it.


THE DAY OF SURGERY

Surgery is often done on an outpatient basis at a hospital or surgery center. You may be asked to skip breakfast, depending on the time of your surgery. You'll probably be told not to eat or drink anything for 6 to 12 hours before the procedure.

Once you arrive for surgery, you will be given eye drops and sometimes medications to help you relax. Antibiotic and anti-inflammatory eye drops are sometimes used before the procedure. You'll be made as comfortable as possible for the procedure. You'll usually wear an outpatient surgical gown, but blankets can help keep you warm. Local anesthesia is often used, which means you feel no pain but are awake during the procedure. Intravenous (IV) medications to help you relax, and nerves in your eye are completely numbed so you can't see or move your eye. In other cases, general anesthesia is used instead, which means you're completely asleep during the procedure.

Anesthesia is either local or general, depending on your age, medical condition, and eye disease. You will not see the surgery while it is happening, and will not have to worry about keeping your eye open or closed. The operation is painless.

You may return home the same day, or a hospital stay of a day or more may be necessary.


THE TRANSPLANT PROCEDURE

The eyelids are gently opened, with a lid speculum. To perform the procedure, we use delicate instruments and an operating microscope. Looking through a surgical microscope, we measure the eye for the size of the corneal transplant. The donor button is then prepared and is usually .25mm larger than the recipient bed. During the corneal transplant, a round portion, usually 8.0mm, of your own problem cornea is removed. The remaining defect is called the recipient bed.

Any necessary additional work within the eye is completed. A cataract may be removed and replaced with a plastic intraocular lens (IOL). Vitreous may be removed from the eye and replaced with fluid. A damaged iris may be repaired. An IOL may be replaced or removed.

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Once the diseased or injured cornea is carefully removed from the eye, it is replaced with a portion of a clear donor cornea. The new cornea is stitched into place using very thin nylon thread. These sutures (stitches) are barely visible and don't cause pain, although you might feel scratching or irritation for about a week after the surgery.

When the operation is over, a shield is placed over your eye.


AFTER SURGERY

If you are outpatient, you may go home after a short stay in the recovery area. You should plan to have someone else drive you home. An examination at our office will be scheduled for the following day.

You will need to:

• Use the eye drops as prescribed.
• Be careful no to rub or press on your eye.
• Use over-the-counter pain medicine, if necessary.
• Continue normal daily activities except exercise.
• Ask your doctor when you can begin driving.
• Wear eyeglasses or an eye shield as advised by your doctor.

Your doctor at Grendahl Eye Associates will decide when to remove stitches, depending upon the health of the eye and the rate of healing.

Proper care is essential for a successful transplant. This care includes medications to help your cornea heal, and a shield or glasses to protect your eye from harm.

Eye drops containing cortisone and sometimes antibiotics help your body accept the new cornea as part of your eye. These drops may be used for several months or longer. Before applying eye drops, wash your hands. Be careful not to touch the dropper tip to anything, including your eyeball, lid, or lashes. If you need to steady your hand, rest it on your nose or cheek. If necessary, have someone else put the drops in your eye for you . You will be given oral steroids as well.

After your surgery, you'll probably wear an eye pad until your next visit, which is usually the following day. An eye shield is also worn for the first 24 hours. After that, clear or prescription eyeglasses or sunglasses can be substituted during the day, but you should continue to wear the shield at night until instructed otherwise by your doctor.

To clean crusting or tears from your eye area, start by washing your hands. Then wet a clean cloth with warm water, squeezing out the excess water. Clean your eye gently, being careful not to get water in your eye. Never rub or press on your eye or eyelid. If the crusting is thick, hold the damp washcloth over your closed eye for a minute before wiping gently.

We may remove some or all of your sutures at any time from several weeks to several years after your transplant procedure. Even after your cornea is healed, you'll continue to visit us regularly for the rest of your life. At these visits, we will monitor your vision for changes and check for any signs of problems. Management of any other eye conditions you have, such as glaucoma, or cataracts may also be discussed. If surgery is necessary to correct other eye conditions, it often can be done without affecting your new cornea.

Your activities are likely to be limited right after your surgery, but you'll probably be back to your old routine in a few weeks. The cornea heals slowly over a period of a year or more, so continuous care and monitoring are essential. It is very important to keep all follow up visits, and follow all instructions carefully.


DURING THE FIRST WEEK

For a few days after your surgery, you may experience discomfort, light sensitivity, tearing, or aching. If any of these are severe, call our office. Don't rub, touch, or get water in your eye. Also, avoid any activity that may result in your eye getting bumped, poked, or hit. To help the cornea heal, a very wet contact lens may be placed on the eye for a few days.


THE NEXT FEW MONTHS

After a week or two, you can usually return to work or school and most other regular activities. You can even return to exercise, but continue to protect your eye from getting hit or poked. We may also remove some of your sutures, but some may remain in the eye for two years or longer.

Rejection happens when the body doesn't accept the new cornea as part of the eye. If not treated quickly, rejection can cause the new cornea to fail. Other problems, such as infection, can also keep the cornea from healing properly. Watch for signs of a problem with your eye. If you notice any of these signs - or anything else unusual - call immediately.

The common signs of early rejection are increased redness, discharge, swelling, sensitivity to light, vision becoming worse, or the development of persistent pain or discomfort in your eye. If rejection is caught in time, treatment with medications can often save the new cornea. If the new cornea fails for any reason, and can't be saved, the transplant procedure often can be repeated. A corneal transplant can be repeated, usually with good results, but the overall rejection rates for repeated transplants are higher than for the first time around.

As your cornea heals, your vision will improve and stabilize. Enjoy your clearer eyesight, but continue watching for signs of rejection, which can happen even years after surgery. With good care and help from us, you can look forward to a lifetime with your new cornea.

Your new cornea needs to last for the rest of your life. Protect it from injury by wearing safety glasses or goggles when there's a possibility something might hit your eye (for instance, while mowing or playing tennis). Take all your prescribed medications as instructed. And don't ever stop watching for signs or rejection.

Your vision will change rapidly during the first few months after your transplant. After your vision stabilizes, we can determine whether glasses or contact lenses will further improve it. If you have astigmatism, it can sometimes be corrected by removing or adjusting some sutures, performing relaxing incisions, wedge resections or LASIK to change the cornea's shape. It may also be corrected with glasses or contacts. Irregular curvature of the transplanted cornea (astigmatism) may slow the return of vision but can also be treated. Vision may continue to improve up to a year after surgery.

Even if the surgery is successful, any other eye conditions, such as macular degeneration (aging of the retina), glaucoma or diabetic damage may limit vision after surgery. Even with such problems, corneal transplantation may still be worthwhile.

A successful corneal transplant requires care and attention on the part of both patient and physician. However, no other surgery has so much to offer when the cornea is deeply scarred or swollen. The vast majority of people who undergo corneal transplants are happy with their improved vision.

Of course, corneal transplant surgery would not be possible without the hundreds of thousands of generous donors and their families who have donated corneal tissue so that others may see.

Corneal topography is a special test (computer analysis) that gives us a full analysis of the curvature of the cornea. A series of concentric circles are projected onto the cornea and the reflex off the cornea is captured and analyzed by a computer. This is like a topographical map of a mountain with elevation contour lines that show a detailed map of the surface of the mountain. The contour lines of corneal topography are arranged in special color-coded areas of the same curvature. Instead of being elevation lines or areas, these are in diopteric powers with a given color representing a given curvature. The hot colors (red, orange, and yellow) represent steeper curvatures and cool colors (green, blue, and purple) represent flatter curvatures. This map is used to plan the exact placement of the scleral pocket or a clear corneal incision and astigmatic cuts in the cornea to correct astigmatism.

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