The move from winter to spring is widely celebrated: few can help but have their spirits lifted by the sight of trees coming into leaf and flowers starting to bloom.
But the advent of warmer weather also brings with it a rise in pollen levels, which can trigger hay fever in those predisposed to the condition.
This week Asha Fowells runs through some of the more common ocular symptoms of this disorder: seasonal allergic conjunctivitis and dry eye syndrome.
Missed yesterday’s episode? Click here
Dry eye syndrome is a condition without a cure, and those who suffer one episode tend to be more prone in the future.
The main self-help measure is to assess what may be aggravating the problem – for example, wearing contact lenses, smoking, using a computer for long periods, or taking medication that can exacerbate dry eyes such as vasoconstrictor eye drops, hormone replacement therapy, diuretics, antihistamines, tricyclic antidepressants and selective serotonin reuptake inhibitors – and then try and mitigate that factor.
Correcting any environmental issues can also be helpful, for example, reducing central heating temperature or using a humidifier to slow down evaporation of tears, ensuring fluid intake is ample to aid hydration, and avoiding eye make up, which may block the tear ducts and cause irritation of the skin around the eyes.
Assuming any other underlying causes have been addressed, mild cases may respond sufficiently to such measures so as to avoid any other treatment.
Omega-3 fatty acids, which are found in oily fish, are sometimes heralded as a solution, but there is mixed evidence as to whether they reduce tear evaporation and inflammation.
For many dry eye syndrome sufferers, ocular lubricants are necessary.
If symptoms are mild to moderate, an artificial tear product is often sufficient.
These include hypromellose, which is cheap and widely available, but requires frequent dosing (every 30 minutes when first starting treatment is not uncommon), and carbomer or polyvinyl alcohol products, which do not need instilling into the eyes as often but may not be as well tolerated.
Sodium hyaluronate is another option, and is popular for its water-retaining properties and low resistance to blinking.
Liposomal – sometimes known as ‘oily’ – eye sprays are available over-the-counter that replenish the lipid component of the tear film, meaning evaporation from the eye is reduced.
These should be sprayed onto closed eyes, never open.
Contact lens wearers can use a sodium chloride (saline) drop, which are short acting and therefore usually regarded as ‘comfort drops’, or a preservative-free product.
These are also considered more suitable for those requiring ongoing application of more than six times a day, as the more frequently a preservative-containing product is used, the more likely it is to cause irritation and/or damage to the cornea.
Patients experiencing more severe symptoms may need to add an ocular lubricant ointment to their treatment.
Paraffin products are cheap and effective, but can blur vision and are not suitable for use with contact lenses, so should only be used at night.
Acetylcysteine drops may be helpful for individuals who have visible mucus strands on their eye(s) because of the drug’s mucolytic properties, but these are likely to sting upon application.
If inflammation is thought to be a component of a patient’s dry eye syndrome, an anti-inflammatory agent may be prescribed, such as a topical corticosteroid, oral tetracycline or topical ciclosporin.
These should only be initiated by an ophthalmologist and require close monitoring.
Very occasionally, autologous serum eye drops – made using components of the patient’s own blood – may be used.
Surgery is reserved for those with severe symptoms that do not respond to other treatments.
The most common procedure is punctal occlusion, which involves sealing the tear ducts so tears do not drain from the eyes and therefore they remain moist.
Very rarely, salivary glands may be removed from the lower lip and placed under the skin around the eyes to act as a tear replacement.
[box type="info" align="alignleft" ]Red flag symptoms
Certain eye symptoms can be a sign that something more serious is going on, and patients should be referred if they complain about:
• pain, rather than discomfort
• disturbed vision
• marked redness affecting one or both eyes
• fixed and dilated pupil(s)
• headache and vomiting
• any sign of ulceration of the surface of the eye [/box]