Dear Dr. K.; My ophthalmologist recently diagnosed me with dry eye syndrome. Is that being caused by my allergy?
The answer is no, yes, or maybe so. I’m not trying to be obtuse, but the answer is different for different people.
Let’s start with the dry eye syndrome. It is very common and affects millions of Americans. Also, it can vary in severity from a mild nuisance to a vision altering severe condition. The common denominator for all people with dry eye syndrome, is compromised ocular lubrication. But, the condition has many causes which can overlap and interact.
Our tears are made by two different tear glands: the lacrimal glands which make the salt water component and the meibomian glands which make the oil component. Dry eye syndrome can be due to inadequate oil production. This imbalance can actually be worsened when the lacrimal glands over-produce the salt water which ends up diluting the oil further. And paradoxically someone with dry eyes might be “tearful”.
Dry eye syndrome can also be due to inadequate lacrimal output. The most common cause for this is certain rheumatologic syndromes especially Sjogren’s Syndrome. But lacrimal deficiency can also occur due to aging, contact lenses, and the drying effect of certain medications such as antihistamines.
Allergic individuals may not have ocular allergy until they develop dry eye syndrome, which leads to a paucity of tears and therefore impedes the natural removal process of allergens from the eye. Then if they take antihistamines to help their allergies they can worsen the drying of the eyes. Other medicines that can contribute to dry eyes include: diuretics, beta – blockers, some antidepressants, birth control pills and some herbal supplements, especially echinacea.
Finally, people who have a reduced blink rate (most commonly seen in Parkinson’s disease) don’t renew the protective tear film on the eyes and experience dry eye issues.