Ocular

Question 1

What is dry eye?

Answer 1

• Common chronic eye condition
• Types:
  
  1. Aqueous deficiency: Disorder in which the lacrimal glands fail to produce enough of the watery component of tears to maintain a healthy eye surface
  2. Evaporative dry eye: insufficient lipid layer coating to the tear film, due to reasons such as meibomian glands (located along the lid margins) that produce oils are damaged.
• Dry eye is a continuum between these two states, some treatments target aqueous deficiency while some targets the evaporative dry eye

Question 2

What are some non-modifiable risk factors for dry eye?

Answer 2

• Age
• Female
• Asian race
• Meibomian gland dysfunction
• Sjogren syndrome
• Menopause
• Acne
• Thyroid disease
• Connective tissue diseases

Question 3

What are some modifiable risk factors for dry eye?

Answer 3

• Computer use
• Androgen deficiency
• Postmenopausal oestrogen therapy/ HRT
• Environment: pollution, low humidity, sick building syndrome
• Medications: antihistamines, anxiolytics, antidepressants, isotretinoin
• Laser refractive surgery
• Omega 3 & omega 6 fatty acids deficiency
• Vitamin A deficiency
• Smoking
• Alcohol
• Botulinum toxin injection
• Hep C infection
• Radiation therapy

Question 4

What are symptoms of dry eyes?

Answer 4

Dry eye generally affects BOTH eyes:
- Irritation
- Grittiness
- Burning
- Soreness
- Watery eyes
- Visual disturbances generally affecting both eyes

Question 5

What are some factors for differential diagnosis to consider when patient complains of dry eye?

Answer 5

• Itch: suggests allergic disease
• Pain/ foreign body sensation: suggests another cause
• Quality of vision: visual quality is dependent on a smooth tear film over the ocular surface so variability in vision between blinks is indicative of dry eye
• Duration & severity: dry eye typically varies with environmental conditions, such as humidity and wind speed, it is a chronic condition and is unlikely to have a sudden onset
• Burning & dryness: common in dry eye
• Dry mouth & other mucosal tissues (e.g. swollen salivary glands for > 3 months): suggests Sjogren’s syndrome
• Stickiness, crusting, discharge of the eye: indicates infection, not dry eye
• Incident associated with the start of symptoms e.g. ocular surgery, starting contact lens wear, foreign body entering the eye or starting new medications: can be indicative of dry eye cause
• Systemic conditions (e.g. allergy & connective tissue disorders): may induce dry eye
• One or both eyes affected: dry eye generally affects both eyes, one painful or red eye suggests possibility that it is not dry eye. However, use of preservatives in eye drops can exacerbate dry eye. Patients using this type of eye drops unilaterally may show greater signs and symptoms in the treated eye

Question 6

What is the pharmacological management of dry eye?

Answer 6

Tear supplementation to relief symptoms
- Topical ocular lubricants: hypromellose, carbomer, polyvinyl alcohol, wool fats, hyaluronate

Question 7

What are the non-pharmacological management of dry eye?

Answer 7

• Use humidifiers
• Stop smoking
• Take regular breaks from computer to encourage blinking
• Avoid wearing contact lenses
• Increase dietary omega-3 fatty acid intake or oral supplementation e.g. salmon, chia seeds, walnuts, flax seeds, anchovies