Corneal and External Disease Treatment

August 17, 2015

 

Beautiful eye close up. Isolated on white background.

A corneal abrasion is a scratch or cut on the cornea — the transparent part of the eye that covers the iris and the pupil.

The cornea helps focus light as it enters the eye. If your cornea is scratched, your vision can be affected or impaired.

Corneal abrasions can be caused by a variety of factors, such as:

  • A small particle flying into the eye, such as dust, sawdust, or ash

  • Dust, dirt or sand becoming stuck under your eyelid

  • Sports injuries where the eye is involved

  • Poorly fitting or dirty contact lenses

  • Being poked in the eye

  • Rubbing your eyes, especially if something is caught in your eye

  • Certain eye conditions, such as bacterial infections

  • Having surgery while under general anesthesia

Symptoms of corneal abrasion

  • Pain in the eye, which may feel worse when you open or close your eye

  • The sensation that there is something in your eye

  • Tearing

  • Redness in the eye

  • Sensitivity to light

  • Blurred vision or loss of vision

  • Headache

If you experience any of the above symptoms, you should seek help from an ophthalmologist, who will perform a thorough eye examination.

A minor corneal abrasion will typically heal by itself in a few days. Your ophthalmologist may use antibiotic eye drops or steroid eye drops to reduce inflammation and reduce the chance of scarring.

If you have a more severe corneal abrasion, your ophthalmologist may place a patch on your eye to reduce discomfort. Medication may also reduce the pain. Wearing sunglasses may improve symptoms of a corneal abrasion while you are healing.

If you wear contact lenses, you should not wear them until the abrasion has healed. Your ophthalmologist will approve the use of contact lenses after you are healed.

Corneal dystrophies are rare genetic eye disorders that can result in abnormalities of the cornea.

Most corneal dystrophies affect both eyes and progress slowly.

 Symptoms may vary depending on the type of corneal dystrophy. Some people experience no symptoms. Others accumulate material in the cornea, leading to blurred vision or loss of vision. Some people may also experience erosion of the cornea. The outer layer of the cornea will fail to attach to the next layer. This can cause mild to severe pain in the eye, sensitivity to light, and the feeling of something in the eye.

 If your eye doctor suspects that you have a corneal dystrophy, he will perform a thorough eye examination and ask about your family history of eye disease. Your ophthalmologist will use a slit lamp microscope to examine the front part of your eye.For people without symptoms, a routine eye exam may indicate the presence of corneal dystrophies. In some cases, genetic testing can be used to identify corneal dystrophies.

Treatment options for corneal dystrophies depend on the type of dystrophy and the severity of the symptoms.

If you are not experiencing any symptoms, your doctor may continue to monitor your eyes closely for signs of progression. Your doctor may recommend eye drops, ointments or laser treatment.

Some people with corneal dystrophy will experience repeat corneal erosion. This may be treated with antibiotics, lubricating eye drops, ointments, or bandage contact lenses that protect the cornea. If erosion continues, your eye doctor may recommend additional treatment options. These options include laser therapy or scraping the cornea.

In more severe cases, a cornea transplant (keratoplasty) may be necessary. During a keratoplasty, the damaged or unhealthy cornea tissue is removed and replaced with clear donor corneal tissue. For some types of corneal dystrophies, a partial cornea transplant may be necessary. Cornea transplants can be successful in patients with poor vision, or whose corneas have been significantly damaged from corneal dystrophies.

 

Many conditions can affect the clarity of the entire cornea. An injury or infection of the cornea can cause scarring. Hereditary conditions such as corneal dystrophy can impair vision.

In these cases, a corneal transplant may be able to restore vision.

 A corneal transplant may be needed if vision cannot be corrected with eyeglasses or contact lenses, or if painful swelling of the cornea cannot be relieved by medications or special contact lenses.

A corneal transplant uses a cornea from a human donor. Before a donated cornea is released for transplant, it is checked for clarity. Tests are also conducted for viruses that cause hepatitis, AIDS and other  infectious diseases.

In a traditional full-corneal transplant surgery (known as penetrating keratoplasty), a circular part of the damaged cornea is removed. A matching area is removed from the center of a donor cornea and sutured into place.

With an EK cornea transplant procedure (endothelial keratoplasty), only the abnormal inner lining of the cornea is removed. A thin disc of donor tissue is placed on the back surface of the cornea. An air bubble pushes the endothelial cell layer into place, allowing it to heal in the correct position.

With a lamellar corneal transplant procedure, the superficial layers of the cornea are removed and replaced with healthy donor tissue. The new tissue is sutured into place.

 The eye connects to the brain through the optic nerve. This sends visual signals from the eye to the brain, which interprets them as images. Although the optic nerve is very thin, it comprises more than one million tiny nerve fibers. If these nerve fibers are cut, they cannot be reconnected. So it is impossible to transplant a whole eye. Even if a surgeon were to implant an eye into the eye socket, the optical nerve could not be reconnected and would not be able to send signals to the brain.

Corneal transplantation is a viable option for many people with impaired vision.

Good vision requires a healthy, clear cornea. If your cornea is injured or affected by disease, it may become swollen or scarred. A cornea that has been damaged by scarring or swelling, or one that is irregularly shaped, can cause glare or blurred vision. In a corneal transplant, damaged or unhealthy corneal tissue is removed and replaced with clear donor corneal tissue.

Corneal transplants are not the only type of eye-related transplantation. Patients who suffer from disorders of the sclera or the conjunctiva (the external eye) may be able to undergo a transplant of amniotic membranes. These can aid in the healing and regeneration of ocular surface tissues.

Doctors continually explore new procedures for transplanting other parts of the eye. In 2010, doctors in France transplanted eyelids and tear ducts as part of a full-face transplant for a man with a genetic disorder. Researchers are also focusing on how to replace damaged retinal cells with healthy transplants. This could potentially lead to a cure for macular degeneration.

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