precorneal

precorneal

anterior to or outside the cornea.

precorneal tear film
the thin layer of secretions from the conjunctival goblet cells and lacrimal, tarsal and nictitans glands that covers the outer surface of the cornea and conjunctiva.
References in periodicals archive ?
10) In all avian species, the necessity of blinking is diminished because of the ability of the third eyelid to spread the precorneal tear film adequately across the cornea.
The ocular surface is normally protected from microbial invasion through an intricate biochemical and anatomic relationship between the cornea, conjunctiva, lacrimal secretory apparatus and precorneal tear film, and the eye lids.
Precorneal tear film stability was assessed by measuring the tear film break-up time by scanning the precorneal tear film with a biomicroscope (Topcon SL1E; Topcon, Tokyo, Japan).
Poor bioavailability of drugs from ocular dosage forms is mainly due to the precorneal loss factors which include tear dynamics, non-productive absorption, transient residence time in the cul-de-sac, and the relative impermeability of the corneal epithelial membrane.
Examination OS revealed normal upper, lower, and third eyelids; marked conjunctival and episcleral hyperemia; adequate precorneal tear film; and a clear cornea.