Dry eye syndrome occurs either due to insufficient production of tears or excessive evaporation of existing tears.
Insufficient Tear Production Insufficient tear production can result from a condition called Sjogren’s syndrome, which is a rheumatic disease. In addition to causing dry eyes, Sjogren’s syndrome also leads to dry mouth. In this condition, the tear glands are damaged due to an inflammatory reaction of unknown cause. Sjogren’s syndrome may coexist with other rheumatic diseases.
When reduced tear secretion is not due to Sjogren’s syndrome, it may occur due to the following conditions:
Aging
Diseases that damage the tear glands (e.g., the type of thyroid disease that affects the eyes)
Blockage of the tear ducts (e.g., eye diseases like trachoma)
Certain neurological diseases (e.g., Riley-Day syndrome)
Excessive Evaporation of Existing Tears Excessive evaporation can result from factors such as contact lens wear and computer use. Problems with the secretion of oil from the glands at the base of the eyelashes can also lead to insufficient oil in the tear film, resulting in excessive evaporation.
Symptoms of Dry Eye Syndrome
Itching
Sensation of foreign body in the eye
Burning sensation
Sticky discharge
Blurred vision
Redness
Light sensitivity
Feeling of fatigue
Diagnosis
Tear Break-Up Time: Normally, tears should remain on the surface of the eye for at least 10 seconds after each blink. The formation of dry areas on the surface before 10 seconds (i.e., tear break-up) is abnormal and indicates insufficient tear production.
Schirmer Test: After numbing the eyes with eye drops, strips of paper marked in millimeters are placed under the lower eyelids. After five minutes, there should be at least 10 mm of wetness on the paper strip. Wetness of less than 5 mm on the paper indicates dry eye syndrome.
Evaluation of the eye surface with various dyes: Fluorescein or rose bengal dyes are applied to the eye surface. These dyes stain dry areas on the surface and shed cells due to dryness. The presence and amount of staining indicate the presence and severity of dry eye.
Treatment
General measures: Humidifying indoor environments, placing water-filled containers on radiators, using cold vapor machines, etc.
Artificial tear drops: These drops moisturize the eyes. Those that do not contain preservatives have no toxic effects.
Tear-enhancing drops: These drops stimulate increased tear production.
Punctal plugs: Tears flow from the eyes toward the nose through small openings called puncta located on the inner sides of the upper and lower eyelids. In individuals with dry eyes, plugs can be inserted into the puncta to prevent the existing tears from draining into the nose. This helps the tears remain on the eye surface.
