DRY EYE & OCULAR SURFACE DISEASE

Dry eye is part of a group of eye conditions called ocular surface  disease. These conditions affect the surface of the eye, including the cornea, conjunctiva and eyelids. Ocular surface disease can be caused by  factors like environmental elements, certain medications, aging, or  underlying health conditions, requiring specialized treatments to  alleviate symptoms and preserve eye health.

Ocular surface disease is often termed “dry eye” because one of the  primary manifestations involves lack of adequate lubrication and  moisture on the eye’s surface. This condition diminishes the eye’s  ability produce sufficient tears or maintain the quality of moisture,  leading to symptoms of dryness, irritation, and discomfort. While “dry  eye” highlights a key symptom, ocular surface disease encompasses  broader issues beyond just dryness, including inflammation and damage to  the eye’s surface.

Symptoms of dry eye can include:

• Persistent dryness or grittiness in the eyes
• A sensation of something foreign in the eye
• Redness
• Excessive reflex tearing
• Sensitivity to light
• Blurred vision
• Discomfort

These symptoms may vary in intensity and can affect daily activities  like reading, driving or working on electronic devices for extended  periods.

Dry eyes can occur when tear production and drainage are not in  balance. People with dry eyes either do not produce enough tears or  their tears are of a poor quality:

• Inadequate amount of tears. Tears are produced by  several glands in and around the eyelids. Tear production tends to  diminish with age, with various medical conditions or as a side effect  of certain medicines. Environmental conditions, such as wind and dry  climates, can also decrease tear volume due to increased tear  evaporation. When the normal amount of tear production decreases or  tears evaporate too quickly from the eyes, symptoms of dry eye can  develop.
• Poor quality of tears. Tears are made up of three  layers: oil, water, and mucus. Each component protects and nourishes the  front surface of the eye. A smooth oil layer helps prevent evaporation  of the water layer, while the mucin layer spreads the tears evenly over  the surface of the eye. If the tears evaporate too quickly or do not  spread evenly over the cornea due to deficiencies with any of the three  tear layers, dry eye symptoms can develop.

Dry eyes can develop for many reasons, including:

• Age. Dry eyes are a part of the natural aging process. The majority of people over age 65 experience some symptoms of dry eyes.
• Gender. Women are more likely to develop dry eyes  due to hormonal changes caused by pregnancy, the use of oral  contraceptives and menopause.
• Medications. Certain medicines, including  antihistamines, decongestants, blood pressure medications, antidepressants, and glaucoma medications can reduce tear quality/production.
• Medical conditions. People with rheumatoid  arthritis, diabetes, and thyroid problems are more likely to have  symptoms of dry eyes. Also, problems with inflammation of the eyelids (blepharitis), inflammation of the surfaces of the eye, or the inward or outward turning of eyelids can cause dry eyes to develop.
• Environmental conditions. Exposure  to smoke, wind and dry climates can increase tear evaporation resulting  in dry eye symptoms. Failure to blink regularly, such as when staring  at a computer screen for long periods of time, can also contribute to  drying of the eyes.
• Other factors. Long-term use of contact lenses can be a factor in the development of dry eyes. Refractive eye surgeries, such as LASIK, can decrease tear production and contribute to dry eyes.

After a physical exam, your doctor can give you special tests to help figure out why you have dry eye. These can measure:

• The volume of your tears
• The quality of them
• How quickly you make them
• How long it takes them to dry up

The tests you might have include:

Schirmer test: Your doctor can give you an anesthetic to numb the area around your eye. Then they’ll put thin strips of paper  in the corners of your eyes and tell you to close them. The paper wicks  away any moisture that comes out and measures it. If the paper takes  too long to get wet, you’re having trouble making tears.

Epithelial staining: You'll  get special eyedrops with dye in them. The dye in the drops helps your  doctor see how quickly your tears are drying out. It also shows them if  you have damage to the surface of your eye. The dye clings to any  damaged cells on your eye’s surface. It can also highlight any ones that  don't have a protective oily layer. The color of the dye in your eyes  is temporary and goes away.

Meibomian gland evaluation: Your eyelids have tiny oil glands called Meibomian glands that line the  edges your eyelids that touch when your eyes are closed. The oil they  make helps keep your tears from drying out. In this test, your eye  doctor will press on them to see if the oil comes out and figure out if  that's the cause of your dry eye. Your doctor may also take a  sample of your tears to look at under a microscope in a lab. They can  tell if a component of tears is missing or low.