Dry Eye Syndrome

A healthy tear film is an important factor in the maintenance of healthy eyes. If a problem with the quality or quantity of the tears develops, then dry eye syndrome may result.

 

The tear film has three layers: a superficial oily layer that prevents evaporation of tears, a middle watery layer that keeps the eye moist and transports nutrients to the cornea and conjunctiva, and a basal mucous layer that helps the tear film adhere to the surface of the eye. If any of these layers is abnormal or deficient then symptoms of dry eye syndrome may occur.

Dry Eye Syndrome

Lacrimal (tear production) gland and the layers of the tear film

 

The most common symptoms of dry eyes are: grittiness, irritation, burning, redness, intermittently blurred vision, sensitivity to light, or just feeling that the eyes are dry.

 

Causes of Dry Eye Syndrome

Dry eye syndrome is common and affects at least 1 in 10 people during their lifetime. The incidence increases with age. It is common to develop some symptoms of dry eyes by 40 years of age. Women are more likely to be affected than men.

 

Some factors that may contribute to the development of dry eye syndrome include:

 

  • Hormonal – more common in women after menopause.
  • Atmospheric – more common in dry, dusty and windy climates.
  • Air conditioning – tear film evaporation increases in air conditioning.
  • Medication – some tablets such as antihistamines and beta-blockers reduce tear production.
  • Computers –use of computers is associated with reduced blink rate and increased tear evaporation.
  • Autoimmune diseases – Sjogren’s syndrome, rheumatoid arthritis and lupus are strongly associated with dry eye syndrome.
  • Neurological disease – Bell’s palsy, a stroke and Parkinson’s disease can result in reduced blink rate and blink effectivity.
  • Contact lens wear – long-term contact lens wear can lead to dry eyes.
  • Smoking – smoking can be harmful to the ocular surface and contribute to dry eye syndrome.
  • Laser Vision Correction – this may precipitate or exacerbate dry eye symptoms.
  • Vitamin A deficiency – more common in developing countries.

 

Illustrations shown are provided courtesy of the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) and Mi-Tec Publishing. The complete RANZCO patient education pamphlet is available from your ophthalmologist