“As a pharmacist, the first thing you need to consider when a patient presents with obvious dry eye syndrome is whether it is being caused by medication that they may be taking”
Treatment While there is no ‘cure’ for dry eye problems, the symptoms can generally be easily controlled. The treatment depends very much on whether symptoms are caused by decreased production of tears, tears that evaporate too quickly or by an underlying condition.
as a pharmacist, the first thing you need to consider when a patient presents with obvious dry eye syndrome is whether it is being caused by medication that they may be taking. If that is the case, then they should be referred back to their gp. Similarly, if you suspect that the condition is being caused by an underlying condition, then the patient should be referred to their gp, as they can then refer the patient to an appropriate specialist.
For those patients, who appear to be simply suffering from dry eye syndrome, then the condition can usually be treated with over-the- counter (OTC) lubricant eye treatments, which are available in drop, gel and ointment form.
These lubricants are often called artificial tears because they replace the missing water in the tear film. However, they don't contain the antibodies, vitamins and nutrients found in normal tears that are essential for eye health.
Artificial tear drops These are synthetic, water-based solutions that are used to lubricate the eye and ‘thicken’ the tears. The drops are usually formulated as solutions or suspension and vary in viscosity. These drops can contain preservatives, which are designed to prevent harmful bacteria growing inside the medicine bottle. These preservatives, if used in large quantities, or over a prolonged period of time, may damage the delicate cells on the surface of the eye, or may cause inflammation.
even if not used over a prolonged period of time, some patients will develop a sensitivity to the preservatives and this can lead to
redness, burning or itching. In these cases, it’s advisable to recommend that the patient uses preservative-free eye drops.
Recent research has found that hyaluronic acid and tamarind seed polysaccharide (TSp) can be very effective in the treatment of dry eyes. Hyaluronic acid is a naturally occurring polymer, which has the capacity to bind up to 3000 times its own weight in water. as such, it can help to reduce evaporation and, consequently, fluid loss from the eyes.
TSp is another muco-adhesive polymer, which is naturally occurring in the body. It produces a visco-elastic solution, which is similar to mucins: important proteins on the surface of the eye.
The combination of the two ingredients means that they mimic the behaviour of natural tears, which obviously reduces the symptoms of dry eye.
Other treatments include:
'Oily' tear eye drops These are drops which replenish the oily part of the tear film and reduce evaporation from the surface of the eye. These preparations are also OTC and include synthetic guar gums and liposomal sprays, which are sprayed on to the edges of the eyelids when the eyes are closed.
Oily tear drops are particularly useful for patients with blepharitis or dry eye syndrome, which is caused by tears evaporating too quickly.
Eye ointments/emollients These products contain lubricating ingredients, which are similar to petroleum jelly. The main advantage that they have over water-based solutions is that they tend to remain in the eye longer. They tend to be used overnight because they can cause blurred vision. patients, who wear contact lenses, can’t use the ointments while they are wearing their lenses.
Medical treatment for dry eyes If a patient does not respond positively to an OTC product, then they should be directed to the gp, particularly if it is an ongoing issue.
The gp may prescribe medication or, in severe cases, refer the patient on to an ophthalmologist, who has recourse to various other dry treatment options, such as punctal plugs, which are inserted into the tear ducts to keep the tears from draining out of the eye.
Home remedies for dry eyes patients can also be advised to try treatments at home for their dry eyes.
These include: • a warm compress where a clean facecloth soaked in warm water is applied to the eyes and gently pressed into the eyelids a few times a day.
• Cleansing eyelids: Inflammation of the eyelids can be reduced by using warm water and a mild soap or baby shampoo. The product should be massaged into the base of the eyelashes.
• using a humidifier: Dry indoor air can exacerbate dry eye syndrome, so it’s vitally important to add moisture to the air. a humidifier can stop the eyes from drying out.
patients should also be advised to make lifestyle changes, such as drinking plenty of water, restricting computer use and wearing wraparound sunglasses.
New hope for treatment of severe dry eye disease
participants in a phase I/II clinical trial of a new enzyme-based treatment for severe dry eye disease experienced reduced signs of disease and discomfort, according to a paper in Translational vision Science and Technology.
The trial compared eye drops containing a biosynthetic form of an enzyme called DNase with eye drops without the enzyme. DNase breaks up nucleic acid-based material on the surface of the eye.
In dry eye disease, production of tears is dysregulated, and the cornea, the transparent outer layer of the eye, becomes inflamed. In severe dry eye disease, which often accompanies diseases such as Sjogren’s syndrome and ocular graft- versus-host disease, the inflammation in the corneal tissue can become extreme enough to cause disabling eye pain and sensitivity to light.
In previous research, Dr Sandeep Jain and his colleagues at the university of Illinois at Chicago had discovered that strands of DNa form webs on the surface of eyes affected by severe dry eye disease. This material causes an inflammatory response that further irritates the eye.
‘In dry eye disease, several things happen,’ Jain explained. ‘There is an increase in the number of white blood cells called neutrophils that gather on the surface of the eye. Neutrophils release DNa which forms webs on the cornea called neutrophil extracellular traps, which cause inflammation of the ocular surface and attract additional neutrophils in a vicious cycle.’
Normally, enzymes present in tears chop up and clear DNa and other debris on the cornea, but in patients with dry eye disease, there is not enough DNase to clear the material.
The 47 participants in the clinical trial were given eye drops containing either DNase or a placebo formulation and instructed to administer one drop of the solution to each eye four times per day for eight weeks. The researchers found that participants in the DNase group had a statistically significant and clinically meaningful reduction in corneal damage at eight weeks compared with the placebo group.
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