Dry eye

The continuous production and drainage of tears is important to the eye's health. Tears keep the eye moist, help wounds heal and protect against infection. The tear film smoothes the surface of the cornea giving it a polished appearance and helping visual clarity.

Dry eye is very common, especially in women after the menopause.

Tears are made mostly by the lacrimal gland (in the upper outer part of the eye socket). Tears leave the eye either by evaporation or drainage. The tear drainage system runs from the inner corner of both eyelids and drains into the nose. Most commonly, dry eyes occur with increasing age due reduced production by the lacrimal gland. It can also occur due to eyelid problems such as blepharitis when the tear quality is poor. Dry eyes can occur in climates with dry air, as well as with the use of some drugs, including antihistamines, nasal decongestants, tranquillisers and anti-depressant drugs. People with connective tissue diseases such as rheumatoid arthritis; can also develop dry eye. Dry eye is sometimes a symptom of Sjögren's syndrome, a disease that attacks the body's lubricating glands, causing dry eyes and dry mouth.

Patients with dry eye complain of chronic discomfort, usually described as a burning, gritty sensation. Some describe a scratchy or sandy feeling as if something is in the eye. Other symptoms include stinging, stringy discharge, heaviness, blurred vision or even watering (if the quality of the tears is poor). The eyes can become red and loose its shiny appearance. You might also see stringy mucus strands and filaments. The tear film on the lower eyelid maybe reduced. The tear break up time may be rapid.

Adding a dye to the eye: fluorescein (orange) or rose bengal (red) may identify dry/damaged areas on the cornea. A Schirmer's test (the amount of moistening of a strip of blotting paper placed in contact with the inside of the lower eyelid) can measure the amount of tear production.

The best treatment is frequent lubricating drops or artificial tears. They are generally available over the counter as drops. Sterile ointments are sometimes used at night, but they can make the vision misty first thing in the morning. Examples of artificial tears are: Hypromellose®, Liquifilm®, Tears Naturale®, Viscotears®, Hypotears® , Gel Tears® and ointments: Lacrilube®, Simple Eye Ointment® Each patient will prefer different drops, and will need them at different frequencies - from once daily right up to every 15 minutes. The drops are cheaper to buy than a prescription charge - but are available on prescription if necessary. Using humidifiers, wearing wrap around glasses when outside and avoiding outside windy and dry conditions may aid relief. For people with severe cases of dry eye, temporary or permanent closure of the tear drains may be helpful. Some people even use swimming goggle type of protection to reduce evaporation.