Neurological
Incomplete lid closure
Many normal patient have incomplete blinks between complete closures. However when the percent of incomplete closures becomes more prevalent the eye gets SPK. The most common entities are Parkinson’s, stroke, and Bell’s Palsy’s. The video is revealing of blink disorders. (Many Bely’s Palsy’s patients have surprisingly little SPK!)
Probable reduced corneal neurons after lasik
A small group of patients get dry eye after lasik. It is well known that there is decreased sensation that returns with nerve ending growth. Confocal microscopy shows this and also around surgical incisions which might be the cause of dry eye sensations after surgery.
The cornea sends afferent impulses to the brain and then efferent impulses to the lacrimal glands and also the blink. We have been successful in some neurotrophic disorders of directly stimulating the glands with secretagogues as dilute Pilocarpine. Other medicines are in development.
