Dry eye

• What are the causes of dry eye

A dry eye can result from things like a dry or windy environment; hormonal changes associated with pregnancy, breast feeding or menopause; or inflammation of the eyelid edges (blepharitis).

Probably the most common cause of a dry eye are aging changes. This is set off by malfunctioning glands in the eyelids (the Meibomian glands), which normally secrete an oily material that forms part of our tears.

This secretion helps retard the evaporation of tears between blinks. When the glands are not functioning properly, the tears evaporate quickly and leave the sensitive cornea exposed. The tear glands then produce an excessive volume of tears as a reflex. In these situations, there are so many tears made that they overflow the normal drainage pathway to the nose and instead spill onto the cheeks.

• What is the treatment of dry eye

Treatment for overflow tearing is directed at the underlying cause and commonly includes supplemental tear drops (yes, a watery eye is often treated, paradoxically, with tear drops), lid scrubs and warm compresses for blepharitis.

There are a variety of artificial tear preparations available. Some patients prefer one over another for their own reasons, so it is a good idea to try different preparations.

If the tears need to be used more frequently than four times a day it is better to choose a preparation that is free of preservatives.

If artificial tears do not adequately relieve the discomfort of dry eyes, closing the openings of the tear drainage system can help to keep more moisture on the eye, making it feel less sore and gritty.

The closure can be performed temporarily, with the insertion of silicone plugs, or more permanently, with surgery. In either case, the procedure is carried out under local anesthetic. In either case, the procedure is carried out under local anesthetic.