• dry feeling
• grittiness
• itching
• burning
• stinging
• redness
• worse reading, PC screen etc

• dull corneal reflex
• fluoroscein punctate stain on cornea & conjunctiva (shines green in blue light)
• blepharitis often associated – red lid margins, crusting of lashes
• mucus in tear film

• Common causes

• Idiopathic/age related
• Blepharitis - causes unstable tear film, premature evaporation of tears
• Prolonged visual attentive tasks e.g. PC screen, reading.

• Less common

• Autoimmune disease
• Rheumatoid Arthritis
• Sjogrens syndrome
• Systemic Lupus Erythematosis
• Wegener’s Granulomatosis
• Primary Biliary Cirrhosis

• Corneal exposure
• Thyroid eye disease
• Facial palsy

• Corneal neuropathy
• Viral keratitis (HSV, VZV)
• Post laser refractive surgery (LASIK)

• Iatrogenic
• Systemic drugs e.g. beta-blockers, tricyclic antidepressants, anti-psychotics, antihistamine

• Rare

• Conjunctival scarring diseases
• Ocular cicatricial pemphigoid
• Stevens Johnson Syndrome
• Chemical or thermal burn

• Vitamin A deficiency
• Malabsorption states
• Intake deficiency more common in developing world

Where possible, modify or treat causes (outlined above).

In most cases, topical lubricants are the mainstay of treatment for dry eye. Treatment is likely to be required long term. Start with liquid drops, which interfere least with vision; if symptoms are not controlled, progress through more viscous gels which have a greater duration of action; ointments last longer and blur vision more but may be useful particularly overnight. Frequency of drops / gel should be guided by symptoms, generally a minimum of three times daily, up to hourly in severe cases. See Topical Lubricants box below.

Remember Blepharitis and treat if present.

Consider preservative free (PF) agents if known preservative intolerance or frequent application is necessary (> 6 doses in 24hrs). Frequent use of preserved agents is likely to cause topical intolerance (redness, stinging, corneal epithelial breakdown due to the surfactant properties of preservatives) hence there is an increasing role for use of PF agents in more severe dry eye. Concurrent use of topical treatment for other conditions e.g. glaucoma will increase the risk of intolerance of additional preserved drops. Contact lens wearers should also be given PF lubricants.

A limited number of lubricants contain ‘vanishing preservatives’, which rapidly break down after instillation; these are suitable for use in contact lens wearers and may be tolerated by patients with intolerance of standard preservatives such as benzalkonium chloride. Preservatives contained in individual products are listed in the BNF and there is a useful guide in MIMS online.

Many eye drops contain excipients other than preservatives e.g. pH buffer systems, so it is possible for intolerance to develop even in preservative free preparations. Genuine hypersensitivity to the lubricating agent itself is highly unlikely.

At each treatment level, individual response / patient preference plays a major role in selecting the agent of choice. Bottle / dispenser design may influence choice – some may be difficult for elderly fingers. Single use vials may be fiddly, but softer to squeeze than a 10ml bottle or pump action dispenser (e.g. Hylo range).

Costs can be significant with frequent use / PF agents. There is no evidence for greater efficacy of one concentration of Sodium Hyaluronate over another, hence the advice is initially to prescribe in a cost advantageous manner (refer to Scottish Drug Tariff) and refine choice depending on symptom response / patient preference. Current recommended agents on formulary, based on cost and efficacy, are shown below (see Topical Lubricants box).

If symptoms persist despite frequent topical treatment e.g. 2-hourly lubricants plus ointment at night, consider referral to an Ophthalmologist. Severe dry eye, with features such as photophobia, reduced vision, mucus filaments or corneal epithelial erosion should be treated and referred at the outset. Suspected systemic autoimmune disease, associated with dry eye, should be referred to a Physician / Rheumatologist.

 REFER TO GENERAL GUIDANCE

• 1^st line

• g. hypromellose 0.5% (Isopto Plain) or 1.0% (Isopto Alkaline)
• g. Polyvinyl alcohol 1.4% (Sno tears, Liquifilm)

• 2^nd line

• g.Carbomer gel 0.2%
• Consider ointment at night e.g. Vita Pos , Xailin

• 3^rd line

• Rapid break down preserved agents
• May be suitable in preservative intolerance
• Suitable for contact lens wearer
• g. Blink Intensive Tears (Sodium Hyaluronate 0.2%) (£2.97/10ml)
• g. Oxyal (Sodium Hyaluronate 0.15%)(£4.15/10ml)
• g. Systane (Hydroxypropyl guar) (£4.66/10ml)

• 4^th line / Preservative Free

• Sodium Hyaluronate (PF) 0.1- 0.2% (choose as per drug tariff – current advice below)
• g. Vismed Multi 0.18% (10ml/£6.81 – shelf life 1 month after opening)
• g. Hylo Tears 0.1% (10ml/£8.50 – shelf life 3 months after opening)
• g. Hylo Forte 0.2% (10ml/ £9.50 – shelf life 3 months after opening)

NB. with frequent use many patients will require > 10ml per month

• Sodium Hyaluronate (PF) 0.4%
• g. Clinitas 0.4% (30 single use units/£5.70)

• g. Carmellose 0.5% (Celluvisc 0.5% single use 30 units £5.75)
• g. Carmellose 1.0% (Celluvisc 1% single use 30 units/£3.00)
• g. Polyvinyl alcohol (PF) 0.4% (Liquifilm PF single use 30 units/£5.35)