DRY EYE



Dry eye is a multifactorial disease causing eye discomfort, visual disturbance and ocular surface damage. These are all very good reasons to proactively treat dry eye. 

Dry eye can be treated carefully considering patient history, general health, medications, chronic or acute symptoms and signs, lifestyle modifications and environmental risk factors. 

Patients with particular medical histories or systemic conditions, on certain medications, of older age groups, with history of eye injury or surgeries may all have increased risk for dry eyes. 

Work or other living environments with intense heat, dust, wind, air conditioning, sun can contribute to dry eye disease.  

Dry Eye Symptoms

  • Dryness
  • Burning / Stinging
  • Scratchy / Gritty feeling
  • Fatigue / Tiredness
  • Irritation / Itching
  • Foreign body sensation
  • Excess tearing
  • Blurred vision
  • Photophobia
  • Red Eyes  
  • Puffy Eyes

Many causes of dry eyes

Heavy reading and screen time
Inadequate breaks
Poor blinking

Environment
Air conditioning / central heating
Windy conditions / fans
Dry climates / low humidity
Dust / smoke
Air pollution
CPAP machines

Health conditions
Diabetes
Autoimmune conditions
Rheumatoid arthritis
Systemic lupus erythematosus
Sjögren’s syndrome
Atopic disease
Thyroid disease

Medications
Antihistamines and decongestants
Anti-hypertensives such as diuretics and beta-blockers
Contraceptive pills
Hormone replacement therapy
Gastrointestinal medications such as proton pump inhibitors
Analgesics such as Ibuprofen, especially in high doses
Antidepressants and anti-anxiety medications
Antipsychotics
Skin medications for acne and psoriasis containing isotretinoin, such as Roaccutane
Chemotherapy
 
Poor diet
Excess pro-inflammatory foods
Inadequate intake of essential fatty acids and anti-inflammatory foods

Dehydration
Inadequate water intake
Excess alcohol or caffeine consumption

Dysfunction of tear glands
Meibomian gland dysfunction
Blepharitis
Lacrimal gland disease
Conjunctivitis 

Contact lens wear
Prolonged wearing schedule
Poor contact lens material and fitting
Reactions to contact lens solutions

Eye surgery
Laser vision correction
Many types of eye and lid surgery; cataract surgery and glaucoma surgery

Eyelid malposition
Droopy lower lids
Incomplete eyelid closure
Floppy eyelid syndrome
Blepharitis
Nocturnal lagophthalmos 

Neuro-pathology
Nerve damage to the ocular surface, lacrimal glands, eyelids

Hormonal
Insulin levels
Menopause
Hormone replacement therapy
Androgen deficiency
Thyroid eye disease
Stress

Poor Sleep
Sleep deprivation causes puffy eyes and dark circles underneath the eyes from fluid and blood retention around the eyes
Poor tear secretion and tear film stability
Increased anxiety and depression leading to higher sensitivity to dry eye symptoms

Age
Dry eye is more common with older age. 
Reduced tear secretion and tear film stability

Ocular Surface Disease Index (OSDI) by Allergan Inc

A widely used survey for assessing dry eye symptoms and how they affect visual function, providing a grading score of severity of dry eye disease.

> Survey is available with open access

OSDI score between 0 to 100
0 to 12 = normal function
13 to 22 = mild dry eye
23 to 32 = moderate dry eye
> 33 = severe dry eye

TEAR FILM

Our normal tear film consists primarily of three layers. When we investigate dry eye, we want to determine if there is a primary deficiency in one or more of these layers.

LIPID LAYER

Lipid is produced from the meibomian glands in the eyelids and released with every blink. This protective outer oil layer promotes tear film stability and prevents the tears from evaporating too quickly. 

AQUEOUS LAYER

Aqueous is produced by the lacrimal glands located behind the outer aspect of our upper eyelids. This central fluid layer keeps the eyes adequately moistened. It is also composed of electrolytes, enzymes, antibodies, antimicrobial proteins, soluble mucin and other compounds. 

MUCOUS LAYER

Mucin, gelatinous glycoprotein, is mainly produced by goblet cells located in the conjunctiva. These mucins form the glycocalyx that protects the eye surface. A smooth slimy surface that allows the tears to distribute evenly over the eye and the eyes to blink comfortably. 

Fortunately, there are many dry eye treatments

Lubricant Eye Drops, Gels and Ointments. 

Eye lubricants help to supplement and mimic the natural tear film. Lubricants may help patch dry areas, moisturise the eye surface reducing friction and providing a protective layer to prevent tear film evaporation.  

Warm compresses

Heat and gentle massage helps to unclog meibomian (oil) glands of the eyelids. A clean facecloth or larger towel can be soaked with hot-warm water from a bowl or the tap (about 40-48°C), wring and place warm cloth over the closed eyelids for 3-5 minutes once or twice daily. Babies and children should use less heat, no more than 37°C for babies and 40°C for children.

Remember for good hygiene use a clean cloth each time. Put these cloths in the wash and line dry in sunlight. Perhaps a pile of small towels near the bathroom vanity will remind one to do hot compresses daily.

Makeup cotton round wipes can be used once and disposed. These small cotton wipes will cool down quickly, simply re-soak and repeat compress. Do not keep them for reuse. 

Blepharitis

The build up of matter along the eyelids and lashes can harbour bacteria and other organisms causing blepharitis, that is, inflammation of the eyelids. Inflammation and oil gland dysfunction contributes to dry eye syndrome. Flaky skin and debris on eyelids can fall into the tear film and cause scratchy irritation. Frequent eye rubbing can worsen the eye surface and skin conditions. Treating eyelid conditions are important.   

Eyelid Cleansers

Sterilid (by Theratears) and Blephadex (by RySurg) foaming eyelid cleansers can help remove accumulated debris and excessive oils from eyelashes and eyelid margins.
These solutions are particularly useful for those with bacteria or dermodex mites involving anterior blepharitis. Used like a shampoo for the eyelashes and lids, the solution needs to be rinsed off completely. Sterilid has a strong menthol-like sensation while Blephadex feels slightly gentler. 

BlephEx 


The BlephEx device uses a disposable rotating microsponge to remove scurf and debris from eyelids. The gentle cleansing procedure takes about 10-20 minutes. This in-office procedure may need to be regularly repeated for some patients. At home treatments should also continue to ensure maximum treatment results. 

Which dry eye drops? How Often?

There are many different dry eye products on the market these days. Patients should be diligent in following the treatment plan prescribed by an eye care professional. Some dry eyes will need frequent lubrication (three to four times a day or more and sometimes even hourly) to maintain ocular surface integrity.

Imagine your dry chapped lips or dry cracked skin, it may feel a bit better after some moisturiser is applied, but sometimes the moisturiser needs to be reapplied throughout the day for your dry skin to heal. We are not skin specialists, but would you only treat your skin when it is cracking, bleeding and hurting?

How often would you need to instill your eye drops for your dry eye surface to heal and maintain good lubrication? Follow your eye care doctor's advice. Non-compliance with dry eye treatment makes it difficult to assess the effectiveness of a treatment plan. Follow instructions, and if unsure, then ask your eye care doctor to clarify. 

For how long should I use these drops?

Ocular lubricants may be prescribed for use "as required" or frequent use for a "treatment period" of 1-2 weeks or more, to allow for surface healing, restoration of healthy ocular surfaces and tear film stability.

Allow some time for your treatment to work as instructed by your eye care professional. If symptoms are not improving as expected, then seek review, because there are many possible reasons for one dry eye product to work for one patient and not for another. Sometimes combination dry eye treatments are needed for moderate to severe dry eye. 

CHECK THE DATE

Label the bottle with an opening date " OPEN on (date) " or expiry date "EXPIRES on (date)".  

Make sure your eye drops are not out of date. Remember that once opened, bottled drops will generally need to be discarded after 4 weeks. Some bottled drops can be used for up to 45 days, 3 months or even 6 months. Check the labels and mark the bottle with "date of opening" or "expiry date".

Always read the labels and be sure you have the correct eye drops before instilling them in your eyes. 

Clinical Articles
> Dry Eye Management: Targeting the Ocular Surface Microenvironment