Corneal disorders and external eye diseases include keratoconus, corneal dystrophies, dry eye disease, conjunctivitis (pink eye) and others. They all occur on the surface of the eye.

Corneal and external eye disease causes

The causes of corneal and external eye diseases depend on the condition. The most common causes of corneal and external eye diseases are:

• Allergies: Pollen and other environmental allergens can affect the eye.
• Blepharitis: This is a chronic eye disease that is caused by bacteria or a skin condition.
• Conjunctivitis (pink eye): This is a group of diseases that causes redness of the eye. It’s usually mild, but it can be severe. Conjunctivitis is usually caused by a cornea virus, bacteria, or allergic or environmental irritants.
• Corneal dystrophies: These are conditions in which the clarity of the cornea is reduced by a buildup of abnormal deposits in the cornea. There are more than 20 types of corneal dystrophies, and most of them are inherited. Corneal dystrophies affect both eyes.
• Dry eye: If the eye is unable to produce enough tears to keep the eye lubricated, this is called dry eye. It’s very common and affects millions of people worldwide.
• Keratoconus: This is a condition where the cornea becomes thin in one area and develops a cone-like shape.

Symptoms of corneal and external eye diseases

The symptoms of corneal and external eye diseases also depend on the condition.

• Allergies: You may have itching, redness, burning or watery discharge. 
• Blepharitis: You may have red, burning or itchy eyes. Light sensitivity and blurred vision are also symptoms.
• Conjunctivitis (pink eye): You may experience watery or thick discharge, swelling, burning and redness of the conjunctiva, which covers the white part of the eye.
• Corneal dystrophies: Some corneal dystrophies cause severe vision impairment, while others cause minimal visual problems.
• Dry eye: You may experience red and inflamed eyes, mucus in or around the eyes, and blurred vision or eye fatigue.
• Keratoconus: Vision typically worsens gradually, though occasionally it worsens quickly. 

Diagnosis of corneal and external eye diseases 

Your ophthalmologist will diagnose your condition in the following ways: 

• Eye allergies: Diagnosing eye allergies requires first checking to see if you have a corneal infection or allergic conjunctivitis. Your eye doctor will then use a slit-lamp microscope to check for signs of eye allergies, such as swollen blood vessels on the surface of your eye. They'll also ask about your family history of allergies.
• Blepharitis: Your eye doctor will examine your eyes with a special magnifying instrument.
• Conjunctivitis (pink eye): Diagnosing conjunctivitis can usually be done by asking questions about your symptoms. Inflammation of the white part of your eye is a key symptom.
• Dry eye: Your eye doctor will do an exam and look at your eyelids and the surface of your eye. They may also test that measure how much tears your eyes produce and how quickly you produce tears.
• Corneal dystrophies: Your eye doctor will use a slit-lamp microscope to examine your eye. They'll also ask about your family history of eye diseases.
• Keratoconus: Diagnosis includes using a slit-lamp evaluation, corneal topography to evaluate the corneal curvature and other techniques to confirm the diagnosis.

Treatment of corneal and external eye diseases 

If you have one of the following conditions, your ophthalmologist will treat your specific disorder. 

• Eye allergies: Your eye doctor will instruct you to avoid or limit contact with the substance that is causing your eye allergies. You many have a skin or blood test to identify the specific allergens. Sometimes eye drops are prescribed.
• Blepharitis: Blepharitis treatment includes putting warm compresses on your eyes for at least one minute. With an eyelid scrub, you soak a clean washcloth in warm water and scrub the base of your eyelashes for about 15 seconds. Your eye doctor may also recommend eye drops that act as artificial tears.
• Conjunctivitis (pink eye): Treatment depends on what type of conjunctivitis you have. If it’s a viral infection, there are no specific treatments. However, placing a cool, wet washcloth on your eyes can help you feel more comfortable. If it’s a bacterial infection, your eye doctor will recommend antibiotic eye drops.
• Dry eye: Your eye doctor may recommend eye drops that act as artificial tears. They may also suggest blocking your tear ducts, which drain your eyes. This saves your tears. Warm compresses on your eyes and massaging your eyelids can also help.
• Corneal dystrophies: Treatment depends on the type of dystrophy you have and how severe it is. If you don’t have symptoms, your eye doctor may monitor your eyes to see if your dystrophy is progressing. If you have symptoms, your eye doctor may recommend eye drops, ointments, laser treatment or surgery.
• Keratoconus: There are a number of treatments for this condition, including glasses or contact lenses, scleral lenses, collagen cross-linking or a corneal transplant.

Why choose Ohio State for corneal and external eye disease treatment

At the Ohio State University Havener Eye Institute, we combine state-of-the-art treatments with personalized eye care for each patient. We work in a collaborative and innovative environment to provide the best outcomes. Our expert patient educators will explain how to take care of your eyes. We offer customized, personalized care and treat every patient with the utmost respect and dignity.