Dry eye, blepharitis and chronic eye irritation: divide and conquer.

Dry eye and posterior blepharitis are the two most common causes for chronic eye irritation. Dry eye is caused by loss of water from the tear film resulting from either decreased tear production or increased tear film evaporation. The resultant increase in tear film osmolarity causes the changes on the eye surface responsible for the symptoms of dry eye. Posterior blepharitis causes eye irritation from inflammation, and leads to the development of meibomian gland dysfunction. The patient history is a powerful tool in narrowing the differential diagnosis of chronic eye irritation or even establishing the diagnosis. The exam adds power to the history, and sorts out the mechanisms causing dry eye symptoms. The primary goal of dry eye treatment is to lower elevated tear film osmolarity. This can be achieved with TheraTears treatment, either with or without punctal plugs. The primary goal of meibomitis treatment is to reduce inflammation. This can be achieved by hot compresses and lid massage and, when necessary, systemic treatment with low dose doxycycline. By determining the cause or causes of chronic eye irritation, effective treatments can be employed.