Exams and Tests

During your eye examination, your ophthalmologist will most likely be able to diagnose DES just from hearing your complaints regarding your eyes. As part of your eye examination, the following tests may also be performed.

• The front of your eyes are 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 break-up 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.
  
  
  • Fluorescein is a yellow dye that stains the cornea where the 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.
    
    
  • Lissamon Green is a green dye which likewise can help differentiate between normal and abnormal surface cells of the cornea and conjunctiva.
    
    
• Schirmer tests measure the amount of tears produced by your eyes. Your 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 DES.
  
  
• The osmolarity (salt content) of the tears may be measured. This is a newer test which has been developed to aid in the diagnosis of DES.
  
  
• If autoimmune diseases are suspected as a cause of DES, blood tests may be performed. These blood tests check for the presence of different autoantibodies that may be associated with DES.
  
  
• Rarely a biopsy of the salivary glands may be performed. Certain disease processes affect both the salivary glands, which produce saliva in your mouth, and the lacrimal glands, which produce tears.