Ocular surface disease, sometimes referred to as dry
eye is a condition in which a person doesn't have enough quality
tears to lubricate and nourish the eye. Tears are necessary for
maintaining the health of the front surface of the eye and for
providing clear vision.
Ocular surface disease is a common and often chronic problem, particularly in older adults. With each blink of the eyelids, tears spread across the front surface of the eye, known as the cornea. Tears provide lubrication, reduce the risk of eye infection, wash away foreign matter in the eye and keep the surface of the eyes smooth and clear. Excess tears in the eyes flow into small drainage ducts in the inner corners of the eyelids, which drain into the back of the nose. Ocular surface disease can occur when tear production and drainage is not in balance.
Causes & risk factors
Ocular surface disease can occur when tear production and drainage are not in balance. People with ocular surface disease 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 ocular surface disease 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, ocular surface disease symptoms can develop.
Ocular surface disease can develop for many reasons, including:
- Age. Ocular surface disease is a part of the natural aging process. The majority of people over age 65 experience some symptoms of ocular surface disease.
- Gender. Women are more likely to develop ocular surface disease due to hormonal changes caused by pregnancy, the use of oral contraceptives and menopause.
- Medications. Certain medicines, including antihistamines, decongestants, blood pressure medications, and antidepressants, can reduce tear production.
- Medical conditions. People with rheumatoid arthritis, diabetes, and thyroid problems are more likely to have symptoms of ocular surface disease. 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 ocular surface disease to develop.
- Environmental conditions. Exposure to smoke, wind and dry climates can increase tear evaporation resulting in ocular surface disease 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 ocular surface disease. Refractive eye surgeries, such as LASIK, can decrease tear production and contribute to ocular surface disease.
Advanced ocular surface disease may damage the front surface of the eye and impair vision.
People with ocular surface disease may experience irritated, gritty, scratchy or burning eyes; a feeling of something in their eyes; excess watering; and blurred vision. Symptoms include:
- stinging, scratching, or burning sensations.
- Light Sensitivity.
- Watery eyes.
- Stringy mucus near the eye.
- Blurry Vision.
Ocular surface disease can be diagnosed through a comprehensive eye examination. Testing with emphasis on the evaluation of the quantity and quality of tears produced by the eyes may include:
- Patient history to determine the patient's symptoms and to note any general health problems, medications or environmental factors that may be contributing to the ocular surface disease problem.
- External examination of the eye, including lid structure and blink dynamics.
- Evaluation of the eyelids and cornea using bright light and magnification.
- Measurement of the quantity and quality of tears for any abnormalities. Special dyes may be put in the eyes to better observe tear flow and to highlight any changes to the outer surface of the eye caused by insufficient tears.
With the information obtained from testing, a doctor of optometry can determine if you have ocular surface disease and advise you on treatment options.
Treatments for ocular surface disease aim to restore or maintain the normal amount of tears in the eye to minimize dryness and related discomfort and to maintain eye health. Ocular surface disease can be a chronic condition, but a doctor of optometry can prescribe treatment to keep your eyes healthy and comfortable and to prevent your vision from being affected. The primary approaches used to manage and treat ocular surface disease include adding tears using over-the-counter artificial tear solutions, conserving tears, increasing tear production, and treating the inflammation of the eyelids or eye surface that contributes to the ocular surface disease.
- Adding tears. Mild cases of ocular surface disease can sometimes be managed using over-the-counter artificial tear solutions. These can be used as often as needed to supplement natural tear production. Preservative-free artificial tear solutions are recommended because they contain fewer additives, which can further irritate the eyes. Generally artificial tears are not a recommended solution for ocular surface disease as it doesn't fix the problem but rather masks it and it is strongly advised to treat the underlying issue rather than mask it. Nonetheless artificial tears is an effective way to give some temporary pain relief.
- Conserving tears. Keeping natural tears in the eyes longer can reduce the symptoms of ocular surface disease. This can be done by blocking the tear ducts through which the tears normally drain. The tear ducts can be blocked with tiny silicone or gel-like plugs that can be removed if needed. Or a surgical procedure can permanently close the tear ducts. In either case, the goal is to keep the available tears in the eye longer to reduce problems related to ocular surface disease.
- Increasing tear production. A doctor of optometry can prescribe eye drops that increase tear production. Taking an omega-3 fatty acid nutritional supplement may also help.
- Treating the contributing eyelid or ocular surface inflammation. A doctor of optometry might recommend prescription eye drops or ointments, warm compresses and lid massage, or eyelid cleaners to help decrease inflammation around the surface of the eyes. There are additional specialized treatments that use light and heat to decrease the effects of ocular surface disease as well. Consult with your eye doctor about these treatment options so see which of these are best for you.
You can take the following steps to reduce symptoms of ocular surface disease:
- Remember to blink regularly when reading or staring at a computer screen for long periods of time.
- Increase the humidity in the air at work and at home.
- Wear sunglasses outdoors, particularly those with wraparound frames, to reduce exposure to drying winds and the sun.
- Nutritional supplements containing essential fatty acids may help decrease ocular surface disease symptoms in some people. Ask your doctor if taking dietary supplements could help your ocular surface disease problems.
- Avoiding becoming dehydrated by drinking plenty of water (8 to 10 glasses) each day.
- Avoid air getting blown in your eyes by directing car heaters away from your face.
- Avoid environments that are drier than normal, such as deserts, airplanes, and places at high altitudes.