Dry Eye Syndrome

The corneal nerves are transected creating a neurotrophic cornea,which can result in neurotrophic epitheliopathy This neurotrophic effect decrease the feedback loop to the lacrimal land and cause a secondary decrease in tear production and dry eye condition

The surface of the reshaped cornea may not hold the tear film as well as before, causing secondary wetting problem The microkeratome may damage the gobblet cells and microvilli, causing s corneal surface problemsAn abnormally low Schirmer�s test result, low tear break-up time (TBUT), and conjuctival and corneal staining with fluorescein, rose bengal or lissamine green are indicative of possible preoperative dry eye syndrome, which predisposes the patient to such problems postoperativelyLow ambient humidity such as occurs during winter months in northern climatesBlepharitis and meibomianitis may also predisposes to surface problems after LASIK surgeryPreventionTreat dry eye syndrome preoperatively with a combination of artificial tear supplements, topical cyclosporine(Restasis), and punctal plugsTreat blepharitis preoperativelyConsider performing a nasal hinge LASIK flapConsider a surface ablation procedureConsider avoiding keratorefractive surgery when the surface problems can�t be satisfactorily improved prior to surgery. Cause