7.17 Wink, wink

("The Wink" - Seinfeld: Season 7, Episode 114, 12 Oct 1995)

The fans of the 1990s "a [TV] show about nothing" known as "Seinfeld" will readily recall "the Wink" episode. In which, a bit of grapefruit juice was accidentally squirted into George Costanza's left eye causing George to wink at inopportune moments.

First, a little info on first-aid: Any time when acid or alkali is splashed onto the eye, the most important first action is to rinse the open eye with copious amount of normal saline, or tap water if saline solution is not available. A few liter or more is generally needed. Then seek immediate medical attention so that the anterior structure of the eye can be preserved. Acid and alkali burns are different. Acid causes protein denaturation on contact. The denatured protein sometimes can form a barrier to prevent further acid erosion. On the other hand, alkali can penetrate deep into ocular tissues. Alkali burn is long-lasting and far more difficult to manage. In either case, saline/water rinsing is the crucial first step.

Back to "Seinfeld". The pH of grapefruit juice is around 3, mild in comparison to, e.g., HCl; although it does cause some discomfort for the eye. Tear fluid in the eye is poorly buffered yet its pH usually stays at a comfortable 7.4, until disturbed. George's winking or twitching, known as myokymia, is from acidic irritation to the nerve endings of the orbicularis oculi muscle in the lower eyelid (occasionally, the upper eyelid can be affected). Myokymia usually resolves itself. In very annoying cases, anti-histamine eyedrops can be used to slow down the muscle contraction. The best one Livostin unfortunately is no longer in production, probably lost out to Botox injection?

There is another uncontrollable winking, know as the Marcus-Gunn jaw-winking syndrome, in which the patient's eye (or eyes) twitches when chewing or suckling. In this case, there is a wiring problem: the eyelid levator muscle, instead of being innervated by a branch of Cranial Nerve III, is now by the motor branch of Cranial Nerve V. It can be regarded as a birth defect; although nothing untoward is involved.

More persistent and chronic twitching of the eyelids of both eyes is known as blepharospasm. It has been noted for years that blepharospasm seems to predate the onset of Parkinson's disease. Recent findings suggest that indeed if there is a lesion in substantia nigra, then Parkinson's eventually does develop. Others report that L-DOPA used to treat Parkinson's can cause blepharospasm. Sort of a lose-lose situation. Other possibilities include the usual suspects: fatigue, dry eye, stress, too much caffeine, etc.

Truly debilitating eye twitching involves half the face, i.e., hemifacial spasm or Meige's Syndrome, that can severely curtail both speech and eating. It is usually a result of inflammation of the facial nerve (Cranial Nerve VII), a sequela of Bell's palsy, or from a tumor or blood vessel pressing on the facial nerve. This can be treated with muscle relaxants, Botox injection, or neurosurgical repair.

Indeed, a wink is not quite just twitching of the eyelid.