Cornea and Occular Surface

Cornea and Occular Surface

About Corneal transplantation:

Cornea transplantation is a surgery used to replace a damaged cornea with a healthy, donated one. Some surgeries remove the entire cornea, while others only remove a few parts. The surgery is used to treat a few different corneal diseases. It is often the best way to treat infection and save sight. In most cases, the surgery is very successful.

About Keratoconus:

Keratoconus is when the surface of the eye bulges out in a cone shape. This happens when the front layer of the eye (the cornea) starts to thin. At first, the bulge may be mild but the condition can get worse over time. It normally affects both eyes.

Causes:

The cause of keratoconus is not known.

Risk Factors:

  • Family history of keratoconus
  • Rubbing your eyes
  • Conditions like retinitis pigmentosa, Down syndrome, hay fever, and asthma

Keratoconus affects about 1 in every 2000 Indians. It is most common in teenagers and young adults in their mid-teens and 20s.

About Corneal Ulcer

Corneal ulcers are a type of inflammation of the cornea. They are typically caused by infection, but can also be caused by injury. With immediate treatment, most ulcers can be treated without vision loss. But if the infection is left untreated or is too severe, ulcers can permanently harm your eyes.

Causes:

  • Eye injury
  • Dirty contact lenses
  • Viruses
  • Dirty water

Risk Factors:

  • Reduced immunity
  • Warm climate
  • Corticosteroid eye drops
  • Eye injury
  • Contact lenses

To reduce the risk of corneal ulcers:

  • Do not wear contact lenses while swimming or for longer than recommended
  • Always clean lenses properly with the correct solution
  • Avoid bathing in rivers or dirty water

The symptoms of the Keratoconus are:

  • Blurry vision
  • More sensitive to light and glare
  • Frequent changes in spectacle power
  • Sudden cloudy vision

One sign of the disease is a bulging cornea. This bulge causes near-sightedness and astigmatisms. In more serious cases, it can also cause swelling and scarring of the eye tissue. See an eye doctor if you have any sudden changes in your eyesight.

The symptoms of the corneal ulcer are:

  • Red eyes
  • Eye pain
  • More tears than normal
  • Difficulty opening your eyelid
  • More sensitive to light
  • Feeling like something is in your eye
  • Blurry vision

Glare or double vision

Bulging Cornea

Colors look faded

Blurry vision

Why is the corneal transplant done?

The cornea may be severely damaged by:

  • Keratoconus (Forward bulging of the cornea)
  • Cornea infection or injuries
  • Corneal ulcers (Keratitis)

About the Surgery:

The surgery usually is finished within 1 hour. An anesthetic will be used so patients don’t feel any pain.  In corneal transplant,

  1. The eye is held open with a speculum (A)
  2. A laser is used to make an initial cut in the existing cornea (B)
  3. The surgeon uses scissors to remove it (C)
  4. Donor cornea is placed (D)
  5. It is stitched with very fine sutures (E)
Picture Courtesy: Surgery Encyclopedia

Types of Corneal Transplantation Surgery

There are two main types of corneal transplantation surgery:

  1. Therapeutic Keratoplasty: for corneal ulcers
  2. Penetrating Keratoplasty: for keratoconus

Risks & Complications

Cornea transplant is a serious surgery. Even though it is safe, it does have a low risk of complications, including:

  • Eye infection
  • Glaucoma
  • Problems with the stitches
  • Rejection of the donor cornea

Rejection occurs when patient’s body attacks the donor’s cornea tissue. Symptoms of rejection include red eye, sensitivity to light, cloudy vision, and eye pain. Tell an eye doctor right away if you notice these symptoms. With early detection, it can be treated with steroid eye drops.

Preparing for Surgery:

Before Surgery:

  1. Get an eye exam from an eye doctor to make sure the surgery is safe
  2. Inform the doctor of all the medicines and treatments you are taking

After the Surgery:

  1. Follow the doctor and counsellor’s instructions closely. Take eye drops or medicines as advised.
  2. Protect your eye from injury
  3. Return for follow-ups with an eye doctor
  4. Avoid bathing in unclean river water

Results

The results will depend on what damaged your cornea. Most people will have at least some vision improvement. It is important that you come for follow-ups to make sure that your eye is healing properly.

Keratoconus

In the early stages, vision can be corrected with spectacles.

In later stages, an individually-fitted hard contact lens must be used. This lens gives better vision. However, it can also increase your sensitivity to light and glare. Finding a comfortable lens can be difficult, but it is important that the lens fit well. Poorly fitting lenses can damage the cornea even more.

If you cannot wear contact lenses or have corneal scarring, your doctor may suggest a cornea transplant.

Another option is corneal cross-linking (also called C3-R). This treatment is new and non-invasive. It works by increasing the strength of the cornea. This may not fix the existing bulge, but it can stop it from getting worse.

Corneal Ulcer (Keratitis)

Treatment for corneal ulcers depends on the cause of the infection. Antibacterial and antifungal eye drops may treat diseases caused by bacteria or fungi. Antiviral eye drops can be used for ulcers caused by viruses. However, these are not a “cure” and the virus may return.

If your ulcer does not respond to medicine, your doctor may suggest a corneal transplantation.

Why do I need a corneal transplant?

The cornea is the clear cover on the surface of your eye. Your cornea may be cloudy, causing you to lose vision. If this is the case, a clear donor cornea should fix the problem. Your cornea can also be damaged by other diseases, infections, and injuries.

After the surgery, will I have any pain or irritation? How long will it take for these side effects to go away?

You will only have a little bit of pain and it should only last for a few days after the surgery. To control the pain, you will take painkillers. In a few cases, the stitches/sutures may break. This will irritate the eye. The sutures may need to be replaced.

How many days will I have to stay in the hospital after the cornea transplant?

This depends on the type of transplant.

  • Therapeutic penetrating keratoplasty (TPK): 5 days
  • Penetrating Keratoplasty (PKP): 4 days

How many days until my vision gets better?

Vision should get batter within 3 months of the surgery. If your doctor tells you to wear glasses, you will need to wear them for vision to improve.

How many months will I need to take medications?

You will need to take them for at least 6 months. Depending on the doctor’s advice, you may need to continue them past the 6 months.

When do I have to come for a follow-up?

You will need to visit your eye doctor after 1 month, 3 months, and 6 months. Sometimes, the doctor may ask you to come back more frequently.

When can I take a head bath?

Usually after 1 month. You should wait for the doctor to tell you that the wound has healed. Also, avoid bathing in river water.

When will the pain from my ulcer start to decrease?

Once the medication starts healing the ulcer, the pain will start decreasing. Painkiller tablets may also temporarily reduce the pain.

Will I get my vision back?

After the ulcer heals, you may require glasses or surgery to get better vision.

When will the ulcer heal and how long will I have to apply the medicines?

This depends on the size of the ulcer. Larger ulcers take longer to heal. The cause of the ulcer is also important. Fungal ulcers take longer to heal. For the fastest recovery, keep your diabetes under control and apply the eye drops as advised.

When should I come back for a checkup?

Whenever your doctor advises.

When can I take a head bath?

You may take a head bath when the ulcer is completely healed. Your doctor will tell you when it is okay.

Can any surgery be done and if so, will it give me full vision?

Surgery is only used as a last resort. Once the ulcer heals, a surgery may be possible to improve vision. Also, if your ulcer does not heal with medicines, you might have to get a corneal transplantation.

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