Cornea and External Diseases

Cornea and External Diseases involve disorders of the cornea (clear, dome-shaped surface that covers the front part of the eye), iris (colored part of the eye), lens, sclera (white part of the eye), conjunctiva (thin membrane that covers the sclera) and the eyelids. Several problems or disorders, such as inflammation, allergies, infections, injuries or dystrophies, can affect all these structures and cause pain or discomfort. If left untreated, it may affect vision and lead to vision loss.

• Conjunctivitis – commonly referred as pink eye, it involves the inflammation of the conjunctiva. Symptoms include itching or burning sensation, excessive tearing, discharge from one or both eyes, sensitivity to light, swollen eyelids or eye redness. Treatment depends on the cause of conjunctivitis – allergy, bacteria or virus. The key is to identify the cause of the disease and avoid self-medication by using over-the-counter eye drops or medicine.
• Pterygium – also known as surfer’s eye or pugita. It is a triangular shaped tissue that grows onto the cornea. It is usually caused by too much exposure to the sun’s ultraviolet (UV) rays, dust and wind. It may be accompanied by eye redness, tearing, foreign body sensation and dry and itchy eyes. Lubricants are prescribed to reduce swelling and redness of small pterygium. Surgery may be required if its growth is large enough that it obstructs vision and causes discomfort.
• Dry eye – occurs when tears do not provide sufficient moisture for the eyes. It is usually due to poor tear quality, decreased tear production, eyelid problems and some medications. When tears do not provide sufficient moisture for the eyes, the eyes try to compensate for it by producing excessive tears. A person with dry eyes may also experience, red, gritty or scratchy eyes, burning sensation in the eyes or eye redness. Instilling artificial tears and taking vision breaks are recommended to ease the symptoms. However, it is best to know the factor that is causing it.
• Keratoconus – occurs when the cornea bulges outward like a cone. Having a cone-shaped cornea causes blurry vision and may cause sensitivity to light and glare. It can affect people age 10 to 25. In its early stages, it can be corrected by wearing glasses or soft contact lenses. As it advances, rigid gas permeable contact lenses or other type of lenses may be fitted. Corneal transplant may also be recommended.
• Eye injuries – Eye injuries can occur in the workplace, at home, when playing sports or due to accidents. It can range from minor injuries, such as getting soap in the eye, to major ones like foreign bodies or chemical burns. These injuries can cause your cornea to be swollen or scarred, distorting your vision. Thus, it is best to avoid touching, rubbing or applying pressure to the eye and see an ophthalmologist immediately.
  • Burns to the eye – Some substances like soap or shampoo can make your eyes burn but will not cause serious eye problems. However, chemicals like acids and alkali, hot fumes can damage the eye.
  • Penetrating eye injuries – Penetrating eye injuries, such as lacerations or open wounds, usually involve tiny projectiles piercing through the different layers of the eye. Some wounds cause foreign bodies to lodge within the eye.
  • Contusion injuries – A direct blow to the eye by a blunt object like champagne cork or clenched fist can cause contusion injuries. Injuries may range from a superficial hemorrhage to more serious conditions like lens dislocation, iris tears, retinal swelling or edema.
  • Other injuries – Corneal abrasion and corneal foreign body are some of the common but less serious eye trauma. Corneal abrasions are the superficial defect in the outer surface of the eye. They may be accompanied by intense pain, tearing and foreign body sensation in the eye. Contact lens wearers usually experience corneal abrasions. Corneal foreign body, on the other hand, is a fragment of an object that can stick to the eye.

Corneal Transplants

Asian Eye is one the few eye centers in the Philippines that performs corneal transplants – Descemet Endothelial Keratoplasty (DSEK) and Deep Anterior Lamellar Keratoplasty (DALK). Aimed at improving vision, these surgeries remove only the unhealthy or diseased layers of the cornea and replace them with healthy ones from a donor.

• DSEK – the damaged endothelial layer (inner lining of the cornea) is selectively replaced with harvested donor cornea without the need for cuts or sutures
• DALK – The diseased front layers of the cornea called stroma and epithelium are removed. The donor cornea is then sutured. DALK is ideal for people suffering from corneal scars, chemical or thermal burns, and keratoconus.

DSEK and DALK lower the risk of cornea rejection of infections. Thus, patients do not have to undergo long-term steroid medications to prevent rejection of the cornea. Long-term use of steroids is a risk factor for blind-causing diseases like cataract and glaucoma. It also promotes shorter visual recovery, better visual outcome, less astigmatism (for DSEK), reduced discomfort and improvement in physical function.