Keratoconus, contact lenses, and seasonal allergies
OT presents a clinical scenario to three of its resident IP optometrists. This week: managing a contact lens and keratoconus patient who is also experiencing seasonal allergies
02 December 2022
- Kevin Wallace, AOP clinical adviser, IP-qualified since March 2012
- Farah Topia, AOP clinical adviser, IP-qualified since July 2016
- Ceri Smith-Jaynes, OT clinical multimedia editor, IP-qualified since November 2018
OT’s panel says...
Kevin Wallace: This patient's allergic conjunctivitis could make contact lens wear difficult, but clearly he needs to wear them. He could use either an eye drop or tablet to treat his symptoms. Sodium cromoglicate eye drops contain a preservative so if the lens has a soft component they would have to be removed a few times per day for instillation, which is not ideal, so an antihistamine tablet may be a better option.
The main problem with both of these is that they need to be taken prophylactically and take a number of days to take effect. In the future, this patient could start the treatment at the time of year when he usually has problems.
In the meantime, he could use a drop such as Olopatidine, which is an antihistamine and mast cell stabiliser. This will provide relief quite quickly and is only required twice a day, so suitable for use in a contact lens wearer. It should only be used for a few months to avoid a rebound effect, but in this case that should be sufficient.
Farah Topia (FT): Patients with seasonal allergies are likely to have other symptoms and to have experienced similar problems in the past. They may have already done some self-medicating. You should clarify what the patient is currently using and also what they might have used in the past and to what effect.
Kevin has covered the use of antihistamine and mast cell stabiliser eye drops, and how to work this around the contact lens use. You can also advise the patient on the use of refrigerator-cooled artificial tears: the cold sensation will help reduce the allergy symptoms, and the artificial tears will help to wash out the allergen. Make sure any artificial tears being used are preservative-free, to avoid any preservative build up on the contact lens and to prevent exacerbating the allergy response or causing any toxicity problems.
As an independent prescriber, I think you can tend to jump straight to the ‘IP options.’ Remember that there are also a number of non-medical things you can advise the patient on
I would have a look at the contact lenses the patient is on and consider whether there is a better option. Most keratoconus patients will be out of range for a daily disposable, but it is important to think about what else you might be able to address.
As an independent prescriber, I think you can tend to jump straight to the ‘IP options.’ Remember that there are also a number of non-medical things you can advise the patient on, such as limiting outdoor activity when pollen levels are high, avoiding drying clothes and bed linen outdoors, wearing wraparound sunglasses when outdoors, and avoiding touching the eyes after being outdoors.
Ceri Smith-Jaynes: I agree with this approach. As Kevin said, sodium cromoglicate isn’t great for contact lens wearers as it is dosed four times a day and it would be hassle removing the lenses if you need them to function. However, it can be bought without a prescription for up to 14 days’ usage. Olopatadine is dosed only twice a day, so can be managed nicely around contact lens wear. It can be used for up to four months, but they will need a prescription.
An alternative drop would be ketotifen. Again, this is dosed twice a day and prescription-only, but doesn’t have the four-month maximum restriction. Then, lots and lots of preservative-free lubricants between doses.
None of these drops need refrigeration but, as Farah said, the cooling effect of a cold drop can be helpful, as can a cool gel mask across the closed eyes. As I understand it, this will constrict the blood vessels, making them less likely to release histamine and making the eyes less red too. I always explain how eye rubbing releases more histamine, making the eyes itchier; it’s such a difficult thing to resist but it does only make things worse.
I’d also investigate the contact lenses and solutions. How are they cleaning the lenses, and can we improve on this? Peroxide or preservative free multipurpose solution (e.g. Regard) can be more suitable. Are they actually reacting to a build-up of surface deposits and do the lenses need replacing or an intensive cleaning with an enzymatic protein remover (e.g. Menicon Progent)? If they are filling the lenses with saline for insertion, is it preservative-free?
If all else fails, and the patient is having dreadful symptoms, then a short course of steroid drops, eg FML or loteprednol, may be helpful. This would be an off-licence use and IOP would need monitoring.
FT: It is important to advise the patient to come back if things don’t improve or if they notice any new symptoms. There is a risk of corneal involvement in patients with severe allergies and you should refer patients on if there is anything you don’t feel comfortable managing.
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