In order to understand the causes of dry eyes, it is important to understand what makes up the tears in our eyes. Tears are generally made up of 3 different layers: Mucin layer at the bottom to help the tears attach to the eyes, the aqueous layer in the middle which form the bulk of the tears itself and a lipid layer over the top that protects the tears from evaporating.
Disruption in any of these layers will lead to dry eyes, and this can be due to microbiological infection, inflammation, inadequate nutrition or can also be the side effects of some ocular surgeries.
However, generally dry eyes can be considered to fall in one of two types or a combination. The first type that is most common is called the evaporative dry eye. This is usually because the Meibomian glands that produce the oil layer is not working effectively and thus the tears evaporate too quickly. The second less common type is aqueous dry eye where there is unsufficient production of tears, which is usually associated with a disorder called sjorgen syndrome.
Treatment for dry eyes would depend mostly on which is the greatest contributing factor. In the case of evaporative dry eyes, in the initial stages would be conservative treatment via home based warm compresses, omega 3 supplements, and lipid based ocular lubricants. In more advanced stages, we may perform in office moist heat treatment coupled with gland expression to stimulate the glands.
Aqueous deficient dry eyes on the other hand would be more difficult to treat, and it would mostly involve frequent use of hypotonic ocular lubricants and potentially would also involve use of punctal plugs (plugs on your tear ducts) to help preserve the tears that you have.
We would also ensure that any inflammatory factors that may contribute to your dry eyes such as anterior blepharitis are tackled.