title: Corneal arcus: some morphology and applied pathophysiology.
abstract: The frequency and density of corneal arcus in 101 patients (101 eyes), 54 males and 47 females, were greatest in the 12 o'clock sector of the peripheral cornea. Sectors below 12, nasally and temporally, were approximately symmetrically affected. Both properties decreased progressively and significantly at the 11 and 1 o'clock sectors, then 10/2, then 9/3; 8/4 and 7/5 differed insignificantly from each other but were significantly less affected than 9/3, and more affected than 6 o'clock. Breadth and density were significantly positively correlated. The greater vascularity and higher temperature at the upper limbus might explain this pattern. The morphology of arcus is concluded to indicate the site of a peripheral corneal filter which prevents ingress of large light-scattering particles with the centripetal flow of tissue fluid. Filtration of immune complexes at the same site may initiate tissue destruction, hence some peripheral corneal ulcerations.
authors.affiliation: Department of Surgery (RIE), University of Edinburgh, Scotland.
authors.forename: C I
authors.initials: CI
authors.lastname: Phillips
authors.forename: S
authors.initials: S
authors.lastname: Tsukahara
authors.forename: S M
authors.initials: SM
authors.lastname: Gore
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001112:Arcus Senilis / Q000473:pathology* / Q000503:physiopathology; D003315:Cornea / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged