What are dry eye syndrome symptoms and signs?
A person with dry eye syndrome may experience dry, gritty/scratchy, or filmy feeling, burning or itching, redness of the eyes (conjunctivitis), blurred vision, foreign body sensation, and light sensitivity.
Symptoms seem to worsen in dry or windy climates and with higher temperatures and lower humidity. Symptoms may also be worse with prolonged use of the eyes (e.g., while reading and watching TV) and toward the end of the day.
Sometimes a symptom of dry eye syndrome may actually be intermittent excessive tearing. With dry eye, when the eyes becomes slightly dry and irritated, it may initiate reflex tearing with the production of a large amount of tears all at once to try to get moist and comfortable again. Unfortunately, the eyes can only handle so many tears at any one time; the rest pour over the eyelids and down the cheeks. Those tears that pour down the cheeks do not help the eyes and are wasted. A short time later, the eyes will become slightly dry and irritated again and the whole process may repeat itself.
During an eye examination, the ophthalmologist will most likely be able to diagnose dry eye syndrome just by hearing the patient's complaints about his or her eyes. Confirmation of the diagnosis can be made by seeing signs of dry eyes. As part of the eye examination, the following tests may be performed:
- The front of the eyes is examined using a special microscope, called a slit lamp.
- The amount and thickness of the tear film are inspected.
- The stability of the tear film is assessed by checking the tear breakup time.
- The conjunctiva is examined to determine if it is too dry.
- The cornea is checked to see if it has dried out or become damaged.
Different dyes may be used during your eye examination. These are placed into the tears in the form of a drop. Fluorescein is a yellow dye that stains the cornea where epithelial (surface) cells have been worn away because of the lack of an adequate protective tear film. Rose Bengal is a red dye that stains the cornea and the conjunctiva where the cells are dead or dying as well as where healthy cells are inadequately protected by the tear film. Lissamine Green is a green dye which can help differentiate between normal and abnormal surface cells of the cornea and conjunctiva.
Schirmer tests measure the amount of tears produced by the eyes. The ophthalmologist places the end of a thin strip of filter paper just inside the lower eyelid. After a minute, the filter paper is removed and the amount of wetting is measured. Less wetting of the filter paper is more indicative of dry eye syndrome.
The osmolarity (salt content) of the tears may be measured. This is a new test which has been developed to aid in the diagnosis of dry eye syndrome, in which tear osmolarity is increased over normal levels.
If autoimmune diseases or Sjögren's syndrome are suspected as a cause of dry eye syndrome, blood tests may be performed. These blood tests check for the presence of different autoantibodies that may be associated with dry eye syndrome.
Rarely a biopsy of the salivary glands may be performed. Certain disease processes, such as Sjögren's syndrome, affect both the salivary glands, which produce saliva in your mouth, and the lacrimal glands, which produce tears.