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

Case study

Charlotte Carter, a 31-year-old woman, asks to speak to the pharmacist.

“Sorry to bother you, but I wondered if you could take a look at my eyes,” she says. “They’ve been sore and watery for a few days now. I thought it was the start of my annual bout of hay fever but my nose hasn’t started streaming in its usual delightful manner so I guess it can’t be. What do you reckon, is it an infection?”

You note that both of Charlotte’s eyes are redder and more watery than usual, and ask about levels of discomfort and any discharge she has noticed. She says her eyes are itchy rather than gritty and she hasn’t found them to be sticky at all, not even in the morning. You ask if she has tried anything yet.

“No, I haven’t, other than leaving my contact lenses out and wearing my glasses instead,” replies Charlotte. “I was going to take my usual antihistamine tablets but then I wasn’t sure if it was hay fever or if I could take them at all as I have just found out that I am pregnant.”

What advice do you provide?

Charlotte’s symptoms are indicative of seasonal allergic conjunctivitis rather than another eye condition. She may be surprised by the absence of nasal symptoms, but this doesn’t mean that hay fever isn’t at play.

Treatment requires careful consideration because of Charlotte’s pregnancy. Oral antihistamines are not generally recommended, particularly during the first trimester and given that she is only experiencing ocular symptoms, antihistamine eye drops are a better way to go as this route of administration minimises the exposure of the foetus to the drug. Mast cell inhibitor products can be used, but with caution and only if there is a clear need, guidance that also applies to topical antihistamines.

Should her eyes recover sufficiently that she is able to wear her contact lenses again, Charlotte needs to make sure she uses preservative-free eye drops as the benzalkonium chloride present in most products can contaminate the lenses. Alternatively, she can instill drops without her contact lenses in, and then insert them after 15-20 minutes, by which time the preservative will have dispersed enough for it not to affect the lenses.

If Charlotte continues to experience symptoms despite using a topical antihistamine, she may need to take an oral agent as well. Chlorphenamine is considered the safest during pregnancy – the safety of the rest of the drug class is not well established in either tests or reports – but the treatment requires a prescription and the doctor should only write it if s/he considers there to be a clear therapeutic need.

It goes without saying that Charlotte should be provided with information on simple non-pharmacological measures she can take that may ease her symptoms, from minimising exposure to pollen by keeping windows closed when driving and showering and changing clothes when getting home, to trying to not rub her eyes too much.

[box type="shadow" ]Tips for using eye drops and ointments

The best way to use eye drops and ointments is to gently pull down the lower eyelid, instil one drop or a thin ribbon of ointment, then keep the eye closed for a couple of minutes. No more than one drop at a time should be instilled – not, as is popularly thought because the second will wash out the first, though dilution and overflow may occur, but because of the increased chance of systemic side effects – and at least five minutes should be left between application of different eye drop preparations, longer if a product with a prolonged contact time, such as a gel or suspension, is being administered.

Eye ointment should always be applied after drops. The likelihood of and extent to which systemic effects occur as a result of ocular drug administration is both unpredictable and highly variable, though eye drops are far more likely to drain via the tear ducts into the nasal cavity where they can be absorbed from the nasal mucosa than ointments.

Applying pressure for a minute or so to the lacrimal punctum near the nose after administering eye drops reduces drainage and therefore absorption.[/box]