“Dry eye” is one of the most common reasons for chronic eye discomfort and blurred or variable vision. There are two main types of dry eye: Aqueous Deficient and Evaporative.

Aqueous Deficient dry eye

This type of dry eye is associated with increasing age and other systemic diseases such as Sjogrens Disease (rheumatoid arthritis), SLE, hormonal abnormalities and auto-immune disease.

Aqueous deficient dry eye means that the eye itself does not produce enough tears to keep the surface of the eye wet and comfortable. This leads to symptoms of dryness, scratchiness and blurred vision. There is no cure for aqueous deficient dry eye, but it can be treated with non-preserved lubricating eye drops and punctual plugs. Punctual plugs are small silicone or collagen inserts that are placed into the tear ducts that take the tears away from the surface of the eye into the nasal passages. There is one duct on the lower lid and one on the upper lid. If lubricants are not sufficient to control dry eye symptoms, then a trial of dissolvable punctual plugs is used to determine if permanent plugs are suitable. The dissolvable plugs last for six weeks, and if symptoms of dryness, grittiness and blurred vision are reduced, then permanent plugs can be inserted in either the lower lid or both upper and lower lids.

Evaporative dry eye

This is the most common form of dry eye and is reported to affect up to 40% of the population. In this case, the eye produces the correct quantity of tears, but the quality of the tears is poor, and they evaporate off the eye at too rapid a rate. This leads to the same type of symptoms seen with AD dry eye: discomfort, especially when working with computers and in air conditioning, grittiness and blurred and variable vision.

The causes can vary from simple allergic conjunctivitis to chronic eyelid disease. There are three layers to the normal human tear film: The Mucus layer that attaches the tear film to the eye, the “salt water” or aqueous layer, and the Lipid or “oil” layer on the front of the tear film that prevents evaporation. In evaporative dry eye it is a disruption of either the mucus or lipid layer or both that causes the problem.

Mucus layer problems occur as a result of chronic allergies or other conditions of the conjunctiva. This can be treated with antihistamine and mast cell stabilizing eye drops as well as lubricants. More significant ocular surface disease problems will involve more complex treatments.

diagram showing demodex living in the eyelash folical and exiting at night

Demodex living in the eyelash folical and exiting at night

active Blepharitis

Active Blepharitis

The most common form of evaporative dry eye is caused by disease of the eyelids, mainly Meibomian Gland Disease or MGD.

The treatments available for MGD in order of severity are:

  1. Lid hygiene.
  2. Warm compresses.
  3. Omega 3 supplements.
  4. Blephasteam Goggles.
  5. Manuka honey eye drops.
  6. Antibiotic eye ointments.
  7. Blephex Lid treatment.
  8. Intense Pulsed Light therapy. (E-Eye)
  9. Maskin Probing.

All of the above treatments are available at the practice except Maskin probing.

Lid hygiene primarily involves cleaning of the eyelids to remove crustiness, dried skin cells and bacteria. There are special cleaning products available for this, including Lid Care and Steri-Lid. Warm compresses are used to heat the meibomian glands in the eyelid to promote the output of meibum (the oily layer of the tear film), and can be performed with a medi-heat pack or Blephasteam goggles. The goggles pre-heat a wet paper film saturated in saline and are worn for 10 minutes.

MGD and dry eye can also be treated therapeutically with Manuka honey drops (Opti-Mel), and antibiotic ointments. Omega-3 supplements also help to normalise the meibum.

Blephex Treatment.

This is a new instrument that is used to manually remove the crustiness caused by a build-up of dry and dead skin cells on the lids that are caused as a result of MGD. In a lot of cases, this is presumed to be caused by the mite Demodex, which normally lives on the skin, but eventually over-populates on the lid margins, in particular the eyelashes. The mite burrows down in the lash follicle and releases waste material and toxins onto the lid surface. This creates the chronic inflammation and infection seen in lid disease. The lashes become “cuffed” and coated with a thick crusty coating that has to be debrided.

Image below : Cleaning the eyelid margin with Blephex Instrument

cleaning the eyelid margins with Blephex

The Blephex instrument, combined with a solution of Tee Tree oil (which kills the mite) is an ideal way of removing the debris. It is painless, with the main sensation being a “tickling” whilst the probe cleans the lid. Follow-up care requires the use of  Blephadex lid cleanser every second day until resolution.

Image below : Before & After Blephex Treatment

image showing eye lid before and after treatment with Blephex

TEAR LAB.

This is the only available instrument that can measure the Osmolarity of the tears. This is highly associated with dry eye. A highly sensitive (and expensive) probe is placed at the outer edge of the lids and collects a small sample of tears. The computer then determines the tear osmolarity, which then helps with decision as to which tear supplements may have a more beneficial effect.

E-EYE Intense Pulsed Light Therapy.

IPL has been used in the beauty industry for many years to treat various skin conditions. It has also been proven to help in the treatment of chronic blepharitis and evaporative dry eye, although the exact underlying cause of the effect is not fully understood at this stage.

A thick layer of gel is applied to the lower lid, and special stainless steel goggles placed over the eyes. The instrument then releases an intense bright red light flash through the lids, with 4 separate flashes along the lower lid being the standard treatment. This is then repeated at 1 week, 2 weeks and 1 month, or 4 separate visits. More may be required. This procedure has a high patient satisfaction rate.