Blink-related microtrauma: when the ocular surface harms itself.

Superior limbic keratoconjunctivitis results mechanically from blinking under prolonged unphysiological conditions. The pathogenic process is known as blink-related microtrauma. This review aimed to explore the validity of a general theory that besides superior limbic keratoconjunctivitis, there may be other diseases of the ocular surface arising from mechanical microtrauma. A review of relevant clinical and microscopic lesions in a range of ocular surface disorders with possible mechanical aetiology was conducted. New terms were selected to facilitate understanding of such new aetiology. Besides superior limbic keratoconjunctivitis, other ocular surface disorders regarded as primarily derived from blink microtrauma are: other filamentary keratitides; blepharospasm and severe ptosis; canthal/palpebral froth; affections from disordered eyelid lining; and contact lens related damage. A group of secondarily microtraumatic disorders was identified, including the example of microtrauma impacting upon interpalpebral bulbar prominences. Superior limbic keratoconjunctivitis is the archetype of diseases affecting a unique combination; namely, the ocular surface conjoined with its lacrimal fluid. It is only one among many diseases actively generated within the confines of 'a self-harming surface'.