Dry Eye after Laser Vision Correction
Why Does it Happen? How is it Treated?

When patients are assessed after LASIK or PRK procedures we find that overwhelmingly the most common complaint we will hear about is dry eye. Patients will describe a gritty foreign body sensation that comes and goes and is much like the sensation that they had encountered prior to surgery while wearing contact lenses. Such symptoms are normal and in fact expected and anticipated with all patients. These symptoms typical come and go over several months and then resolve.

Laser vision correction procedures all share one thing in common; the application of Excimer laser energy to reshape the cornea and allow it to focus more efficiently. Inevitably some sensory nerves that live in the cornea are affected by the applied laser treatment. These nerve fibers are responsible (among other things) for sending information to the central nervous system about the state of hydration on the ocular surface. When the laser alters these fibers, a temporary interruption of the feedback mechanism between the ocular surface and the brain is created. As a result the message to the brain to create additional tear film when the eye becomes dry is faulty and the familiar family of symptoms symptoms result.

These nerve fibers regenerate over several months resulting in a resolution of this neurological issue. In the interim patients are supported with topical lubricants and a medication called Restasis (cyclosporine). This drug helps in increasing tear volume as the eye heals.

Essential in the process that we use to screen patients is an evaluation of the tear film. We inspect the tear film to assure stability and also measure tear osmolarity by way of a technology called Tear Lab. Patients who test higher in osmolarity are likely to have a tendency to dry eye. Candidates interested in Laser Vision correction who present with findings compatible with dry eye are treated to improve the clinical situation. Once improvement is document patients may be cleared for surgery.

In uneventful Laser Vision Correction the incidence of prolonged complaints relating to ocular dryness is less than 1% of patients. In general these tend to be individuals with a history of ocular inflammation stemming either from allergic or contact lens wear issues.

Article by
New York Ophthalmologist