Dry Eyes are one of the most common ocular surface problems seen by ophthalmologists today with over 4 million people in the UK estimated to suffer from this condition.
It occurs when an individual does not produce enough tears or the composition of the tears is abnormal and cannot adequately cover the surface of the eye. The tear film is an essential part for ensuring the overall health of the ocular surface. It cleanses, lubricates, and nourishes the surface of the eye as well as protecting it against infection. Both the quality and quantity of the tears must be maintained within certain levels to ensure a healthy and clear refractive surface essential for good vision.
There are many symptoms associated with dry eye, the most common being:
- Grittiness or Sandy Feeling in the eyes
- Burning or Stinging sensation
- Itching and Scratchiness
- Soreness or Painful
- Foreign body sensation
- A feeling of Dryness
- Sensitivity to light
There are many different causes of dry eye. Some of the most common causes are shown here.
- Adverse Environmental Conditions: Air conditioning, low humidity in aeroplanes, central heating, car heaters, windy weather and smoky environments can all cause tears to evaporate more quickly resulting in a feeling of irritated eyes.
- Contact Lenses, Watching TV and looking at a Computer Screen for long periods of time can all result in a decrease in your rate of blinking which adversely affects your tearfilm.
- Hormones: Many women find that they experience dry eye symptoms on reaching the menopause.
- Medications such as anti-depressants and anti-histamines
- Age: The incidence of dry eye increases with age due to the natural aging process.
- Blepharitis – Bacteria and inflammation of the lids can restrict the proper functioning of the meibomian glands that are involved in producing lipids essential for a healthy tear film.
- Sjögren’s Syndrome :This is an autoimmune disorder that affects the lacrimal gland that is responsible for normal tear production.
- Other causes of dry eye include chronic allergies and conditions such as rheumatoid arthritis and lupus.
The criterion for the accurate diagnosis of Dry Eye can be complicated and is often controversial amongst clinicians and researchers. This is because there is a wide variety of ocular surface assessments and clinical diagnostic tests currently available some of which do not always correlate with patient symptoms.
Some of the most common tests are:
- Dry Eye Questionnaire: this helps the ophthalmologist to assess patient symptoms and correlate them with signs of tear film disorders. Free online dry eye questionnaire to find out immediately if you may have dry eye.
- Physical Examination: The ophthalmologist will perform an assessment of the whole surface of the eye looking for signs of inflammation and meibomian gland disorders, which are often connected to tear film abnormalities.
- Phenol Red Thread Test: A small thread which changes colour from yellow to red when wet is placed into the lower conjunctival sac for 15 seconds to measure tear volume.
- Schirmer Test: this is a simple test to measure tear production and is performed by placing a filter paper strip over lower eyelid for 5 minutes. The amount of tears absorbed into the paper in this time indicates whether there are enough or too little tears being produced.
- Assessment of Tear Film Stability: Evaluation of the stability of the tear film is considered to be one of the most useful tools for the diagnosis of dry eye since an unstable and unrefreshed tear film is one of the most indicative signs of the presence of dry eye. The measurement of tear stability can be carried out by measuring the time in seconds between one complete blink and the first appearance of a discontinuity or dry spot in the fluorescein stained tear film. Many ophthalmologists consider the assessment of tear film stability by use of fluorescein to be the most important clinical diagnostic test available today.
- Impression cytology to look at goblet cell numbers in the conjunctiva: The ophthalmologist takes a small sample of cells from the surface of the eye using a small piece of specialised filter paper. These cells that are collected on the paper can stained so the number of goblet cells can be counted. People with only a small number or even none of these cells usually have Dry Eye.
Management of dry eye is usually a combination of treatments and lifestyle changes that are tailored to the needs of an individual patient. Professor Moore believes that there are two main goals when addressing the treatment of his dry eye patients. “My primary aim is to alleviate symptomatic discomfort and then secondary to prevent or reverse complications and further ocular surface damage that may cause a deterioration of their vision.”
- Artificial Tears: “While many find rapid relief using artificial tears, often this reprieve is short-lived with the patient having to use them up to eight to ten times per day,” explains Professor Moore. Indeed some artificial tears contain preservatives that may in fact exacerbate the problem and therefore it is often recommended that non-preservative tear supplements should be the first choice.
- Warm Compresses: Some patients’ symptoms can be alleviated by applying warm moist compresses to the skin of closed eyelids which allows easier release of lipids from the meibomian glands.
- Surgery: blocking of the tear duct with a permanent or semi-permanent plug (usually silicone, collagen or plastic) often helps those with severe dry eye by preventing the drainage of the tears.
- Eyelid Massage: Eyelid massage is key to managing dry eye problems. Eyepeace is a new, unique, CE marked medical device created by two leading consultant ophthalmologists, Professors Johnny Moore FRCOphth, PhD and Anant Sharma MA FRCOphth. The eyepeace is designed to combat the issues of Meibomian Gland Dysfunction (MGD), dry eye, blepharitis and chalazion. It is specially designed to be a non-invasive way to massage the meibomian glands in a vertical motion and resulting in the treatment and prevention of dry eye. Further information can be found via www.eyepeace.org.uk