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Dry Eye

Tears are essential in protecting the front surface of the eye from the environment and to maintain a smooth ocular surface. Combined, these ensure that the quality of vision is optimised.

Dry Eye occurs when the tear film is disrupted. Patients with dry eye experience redness of the eyes, tearing, stinging, burning, gritty sensations, light sensitivity, contact lens discomfort, eyelids that stick together on waking and fluctuating vision performance.

Common medications linked to ocular dryness include antihistamines, oral contraceptives, anti-psychotics, anti-depressants and beta-blockers.

There are two types of Dry Eye; Evaporative Dry Eye and Secretive Dry Eye.

Evaporative Dry Eye

The meibomian glands

The meibomian glands

Oil secreting structures, known as meibomian Gbands, are found behind the lash line. There are about 30-40 glands on the upper lid margin and 20-25 glands on the lower lid margin. These glands secrete oils that form the outermost layer of the tear film to reduce tear evaporation. Evapourative dry eye develops when meibomian glands become blocked and secretions remain stagnant in the glands. This creates a site for bacterial growth. Consequently, the quality of oily layer of the tears is reduced and tears evaporate rapidly. Extended computer use, smart phone use, near work, air conditioned spaces, low humidity, windy, smoky, polluted environments are aggravating factors.

Inflamed eyelids, also known as blepharitis, may lead to dry eye. Inflammation of the lid margin may occur due to bacterial colonization such as Staphylococcus aureus or can coexist with skin conditions such as acne rosacea, psoriasis and scalp dandruff. The inflammation adversely affect meibomian glands resulting in meibomian gland dysfunction and evaporative dry eye.

Secretive Dry Eye 

Lacrimal glands produce the aqueous component of tears. This layer comprises water, electrolytes and proteins. It is responsible for tear spreading. Secretive Dry Eye manifests when the aqueous layer is deficient. Associated systemic conditions include Sjogren syndrome, rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis or lymphoma. This type of dry eye is less common than the former.

Treatment

Omega-3 fatty acids are anti-inflammatory supplements. Increasing omega 3 fatty acid intake have shown to improve tear film stability and provide symptomatic relief. Greater the omega 3 to omega 6 ratio results in less inflammation. Research has demonstrated that omega 3 supplementation enhances the health-associated quality of life of patients with meibomian gland dysfunction.

Meibomian gland expression is an in-office form of treatment conducted by our optometrists. It involves the use of a specialised expressor paddle to decongest blocked glands.

Lid hygiene is improved with lid scrubs (i.e Sterilid or Avenova). These preparations are an antibacterial agent which clears oil, debris and bacteria that accumulate in the lids and lashes.

The warm Bruder Eye Hydrating Mask, available from Eyes on Ardmore

The warm Bruder Eye Hydrating Mask, available from Eyes on Ardmore

Warm compresses with heated wheat bags liquefies the stagnant lipids in meibomian glands to aid it’s outflow. The Bruder MediBeads Eye Mask is preferred over heated towels or wheat bags as they produce a moist heat and retain heat longer. 

Eye lid massage can be done with a cotton bud or with fingers. Cleanse the lids with a warm wet flannel and massage upper lid from the top of the eye lid down towards the lash line. With respect to the lower lid, starting at the bottom of the lid, massage up, towards the lash line.

Artificial tears (i.e. Systane Hydration or Balance) can temporarily alleviate symptoms. These are lubricating eye drops appropriate for use during waking or sleeping hours. Lubricating night-time ointments are more viscous than eye drops. These are suited for use while sleeping (i.e. PolyGel). It’s best to avoid preservatives when choosing eye drops and ointments, as preservatives can further disrupt the tears. 

Lifestyle modifications entail taking frequent breaks during extended periods of near work, ensure complete blinks, increase surrounding humidity with humidifiers, avoiding the use of air conditioners and the use of eye masks for those with incomplete lid closure during sleep (nocturnal lagophthalmos).

References

  1. Foulks G, Lemp M, Jester J, Sutphin J, Murube J, Novack G. report of the international dry eye workshop (DEWS). Ocul Surf. 2007;5(2).
  2. Nichols K. Blepharitis and dry eye: a common, yet complicated combination: the diseases often co-present, which may confound treatment priorities. Review of Optometry. 2010 Aug 15;147(8):39-45.
  3. Thode AR, Latkany RA. Current and emerging therapeutic strategies for the treatment of meibomian gland dysfunction (MGD). Drugs. 2015 Jul 1;75(11):1177-85.
  4. Hatley J. Essential procedures at the slit lamp: how to impress (and express) your patients. Review of Optometry. 2015 May 15;152(5):67-75.
  5. Yao W, Davidson RS, Durairaj VD, Gelston CD. Dry eye syndrome: an update in office management. The American journal of medicine. 2011 Nov 30;124(11):1016-8.