HARTFORD — Punctate Keratitis is irritation of the cornea, the outer coating of the eye. Lots of things can cause it but some common causes is overuse of contact lenses, viruses, UV light, and irritation from smoke, chemicals, preservatives, or make-up.
Alrex is a steroid to reduce inflammation and Vigamox is an antibiotic. The Alrex is no more effective at reducing inflammation than generic prednisone drops that cost much less. Alrex does have advantages in people with glaucoma and is safer for long term use. Similarly, the Vigamox contains moxifloxacin and there are eye drops that use other antibiotics which are less expensive but some of them can cause eye irritation and there is some emerging resistance with some of them. Long story short, whenever you are being given a prescription you need to let your doctor know that cost is important to you and ask about the advantages over alternatives that are less expensive.
While there are many products on the shelf, there are only few active ingredients in artificial tears. The first is the thickener that keeps it on your eye. Methylcellulose, polyethylene glycol, polyvinyl alcohol, glycerin, and oil based products. If your doctor tells you that you had blepharitis or evaporative dry eye where you make enough tears but they evaporate away too quickly, than a product with castor or mineral oil is worthwhile. No one has clearly demonstrated differences between the other active ingredients in the products, they are just similar different means to an end. If the product has a higher concentration of the thickeners, is will last longer on the eye but can cause more blurred vision when you put it in and the blurred vision can last longer. For example, an ultra-thick formulation could cause blurred vision for 30 minutes which is inconvenient for many people where moderately thick products only cause blurred vision for 15 minutes.
The next thing is the preservatives in the product. You should avoid products with benzalkonium for long term use because it can irritate the eye and cause the same condition you are trying to treat. Gentle preservatives such as Purite, Polyquad or GenAqua are ok to use longer term. Preservative free products come in single use containers and are very expensive but some people need to use them because they are very sensitive to the preservatives.
Finally, some products contain “guar” which is supposed to stick more tightly to the inflamed and injured surface of the eye. This might be an advantage if other less expensive products are not helping. In most cases, the brand name products have a generic version next to them with the same ingredients but at a lower cost. Even with all these ingredients though, artificial tears will never be as good as regular tears which contain natural protein thickeners, cellular growth factors, antibacterial enzymes, and natural fats that coat, strengthen, and help heal the eye. So I think the viewer probably made a good choice with whatever artificial tears product she picked but these tips can help her select a product more targeted to her liking and her price point the next time.
– Dr. Michael White from the UConn School of Pharmacy
