Up to 90% of patients with allergic rhinitis (hay fever) also report having itchy, red, watery eyes (allergic conjunctivitis). Some of the medications used to treat allergic rhinitis can reduce symptoms and signs of allergic conjunctivitis. However, when additional relief is needed, patients may use an eye drop containing an antihistamine. They can be quite effective. So the next question is which eye drop should you use? Here's my approach.
1. First, always use lots of sterile saline drops to physically wash allergens off of the conjunctiva. Think of it as a shower or a car wash.
2. Irritated conjunctiva are very sensitive to movement even from blinking, so a lubricant like a small amount of petroleum jelly may be helpful. This is sold over-the-counter as petroleum jelly, generic eye ointment, or Stye ointment.
3. Eye drops of antihistamines help. Over-the-counter may be tried first, such as Visine-AC or Zaditor or Opcon-A. They used to be prescription items. If these are not effective, then come prescription eye drops. There are several available. Most patients these days will find themselves steered to either Pataday or Optivar for the simple reason that their manufacturers are actively marketing them to the public and to physicians. We are less likely to recommend other eye drops in part because there are no samples for us to offer to patients to try before they buy 1-month supply bottles. Which is the best? It's hard to say. There are only a few comparison trials, which to my knowledge showed equal efficacy and roughly equal adverse effects. My nurse and I did an unblinded trial in my office, where we put 1 drop of either Pataday or Optivar in our eyes. The Pataday did not burn, whereas the Optivar burned a 6 of 10 for about 1 minute and then went away. We did not notice any difference between our eyes. Patanol is the 0.1% strength eyedrop, given 2x/day. Patanase is the 0.2% eyedrop, given 1x/day. Optivar is given 2x/day. One bit of feedback some patients using Patanse is that they think the Patanase does not last the entire day, and so they end up using an additional drop in the evening. It think this is safe to do, but logistically, this uses up the reportedly small bottles more quickly, and so in the end winds up costing more to patients. To see photos of all eyedrops, go here.
4. Eye drops of corticosteroids are very effective, but the choice of absolute last resort, in my opinion, because the risk for elevated eye pressures (known as glaucoma) and over time the risk for clouding of the cornea (cataract of the lens). Both are not good.
In summary, if your eyes bother you, you can do something about it. Check your insurance booklet, or better yet bring it with you to every physician visit, so your physician can check which of these eye drops is preferred on the formulary. When 1 fails to give relief, then try the other.