Conjunctivitis is a very common inflammation of the tissue (conjunctiva) that lines the eyelids and the white part of the eye. When this inflammation is due to an allergy to substances like tree/flower pollen or dander, it is classified as allergic conjunctivitis.
Why does this happen? Just like elsewhere in the body, when your eyes are exposed to things you are allergic to, a substance called histamine is released. Histamine causes blood vessels to dilate (get bigger or appear more prominent) and creates an excess of fluid in the area. This is what creates the common signs and symptoms of allergic conjunctivitis: redness and itching of the eyes, excessive tearing, and puffy eyelids.
Contact lens wear presents additional challenges to allergy sufferers as a contact lens can bind proteins and allergens that the eye reacts to. During a bout of allergic conjunctivitis, contact lens wear is often avoided because:
- Excess tearing and eyelid inflammation makes the contact lens move more on the eye leading to discomfort and unstable vision
- Contact lenses have a tendency to prolong allergic conjunctivitis by increasing exposure to allergens and physically irritating the inflamed areas of the eyelids.
So what is an eye allergy sufferer to do? Some people with very specific allergies might be capable of avoiding the trigger. For example, we’ve had patients who only get allergic reactions when they used a certain brand of makeup. Eliminate the makeup and the allergic response of the eye disappeared.
However, most people will have more widespread environmental allergies and, for them, avoiding the triggers is impractical. For these people, topical medications (ie. eye drops) can eliminate the itching and redness that makes their eyes so uncomfortable during allergy season. Contact lens wearers may also benefit greatly from topical medications, but a more thorough evaluation of their history (ie. contact lens material, replacement schedule, disinfecting solution) often yields possible alternate treatment plans.
One more thought: Many allergy sufferers take a systemic allergy medication such as Allegra or Claritin and assume that this will take care of the eyes, but then struggle with allergic conjunctivitis. While systemic allergy medications will sometimes take care of the eye symptoms, they also have a tendency to dry the eye out. This results in it being easier for allergens to bind to the eye and create an allergic reaction. That’s why often the most effective way to treat eye allergies is by treating the eye directly with drops.
What’s the mechanism here? Does the allergic reaction come from pollen getting in the eye or is it symptomatic of general allergic reaction?
I’ve nearly eliminated respiratory and sinus issues with regular Neti-pot use (sinus rinsing), especially after bike-rides. But I still get the conjunctivitis. Allergy meds are not a good solution for me, can’t handle side-effects.
Great question.
The allergic mechanism/cascade is the same in the eye as it is elsewhere in the body. But eye symptoms usually indicate some localized response to an allergen. Of course it’s possible that the eye response is secondary to a main reaction elsewhere, but itchy, watery eyes generally indicate direct eye exposure to the allergen.
Have you discussed topical treatment of your eye symptoms w/ your eye doctor? Eye drops often offer the advantage of quick relief (or even prevention) of symptoms without the side effects of systemic allergy meds. Could be as simple as putting a drop in before you head out on the bike.
Thanks for the question, Doug. Let me know if that raised more questions than it answered
Thanks for the answer Doc. I’m going to try some allergy-relief drops before riding and see what happens.
I’ll keep you posted.
Just to clarify as it might have been ambiguous above:
My discussion of eye drops was referring to a class of drops called combination anti-histamine/mast cell stabilizers. Previously available by Rx only, one of these drugs (ketotifen fumarate) came off patent protection in the past year or so and can be found on the shelves under the name Alaway. Its recommended use is one drop, two times per day. Your eye doctor, of course, has access to similar and stronger medications should that not be satisfactory.
I just got back from riding, one drop each eye before, and same after. Today is prime-time for allergy, so if I were to have any problems, now would be it.
So far, so good. Thanks a bunch Doc!!
Great to hear!