Dry eye can be broadly classified into two types which have different causes. The two types are:
Aqueous deficiency dry eye
Aqueous deficiency dry eye refers to insufficient production of tears. It can be caused by autoimmune diseases such as systemic lupus erythematosus (SLE) and Sjögren’s syndrome. Certain drugs such as antidepressants, antihistamines, antihypertensives and glaucoma eyedrops can decrease tear production as well. Hormonal changes in menopasual women, hormone replacement therapy and eye surgeries such as LASIK and cataract surgery are also known causes of this form of dry eye.
Evaporative dry eye
Evaporative dry eye refers to excessive evaporation of the tear film. It can be caused by intrinsic factors such as blepharitis and reduced blinking rate, or extrinsic factors such as contact lens wear, vitamin A deficiency and environmental factors. These include air-conditioned, dusty, windy and low humidity environments.
- Excessive tearing
- Increased blinking
More severe cases can cause:
- Transient blurring of vision
- Burning sensation
Dry eye can be diagnosed during a slit-lamp examination by an eyecare professional. In addition, a number of tests such as Slit Lamp Examination, Tear Break Up Time, Schirmer’s Test, Ocular Surface Disease Index (OSDI) to assess the quantity and quality of tears can help to determine the severity of the condition.
The management of dry eye is aimed at relieving the dry eye symptoms and increasing tear production. In most cases, dry eye is a chronic condition and is likely to recur when treatment is stopped. Simple measures such as wearing protective spectacles (eg, Cocoons or Jonathan Paul fitovers) and avoiding dry, windy or dusty environments may be helpful.
Eye lubricants, also called artificial tears, can help to keep your eyes moist. The lubricants may be in the form of lubricating eyedrops (generally for day time use) or gel (often used at bedtime).
Artificial tears are available with and without preservatives. The preservatives in preserved eyedrops may cause allergic reactions or worsen the dry eye condition in some patients, especially if used frequently. Preservative-free artificial tears, on the other hand, are gentler on the eye and are better tolerated by the eye.
Restasis is a prescription eyedrop that can increase your eyes’ natural ability to produce tears. When beginning Restasis therapy, you should continue to use your eye lubricants as it may take a while (usually 1 month) before you begin to experience the results of increased tear production. The first sign many patients may notice is that they are using their usual eye lubricants less frequently.
Punctal plugs are tiny stoppers smaller than a grain of rice that are inserted into the puncta to block the drainage of tears. They reduce tear drainage and retain moisture in the eye, thus alleviating dry eye symptoms. There are generally two types of punctal plugs:
These plugs, made from short-lasting materials such as collagen, usually last from a few days to as long as several months. They do not need to be removed as they dissolve on the own and are absorbed by the body. They may be used to determine if the treatment works for your dry eye condition.
These plugs, made of longer lasting materials such as silicone, allow the puncta to be occluded for a longer period of time than temporary plugs.
Dry eye is a chronic condition that tends to persist for many months to years and it can be difficult to achieve permanent relief of the symptoms. Compliance to treatment is the key to achieving symptomatic relief from the conditions.
One approach is to treat this condition aggressively in the initial stages so that you can experience improvement in your symptoms. Early success encourages compliance to treatment. Once complete relief is achieved, you can then slowly experiment to reduce the amount or frequency of your medications. The aim is to use the minimum medications to achieve the desired relief. Although it may not be possible to eradicate the conditions in every patient, most patients can get significant relief from their symptoms and improve their quality of life.