title: Ring corneal clouding in keratoconus.
abstract: Rings of corneal edema were noted in one eye of each of three keratoconic patients, all wearing McGuire design rigid contact lenses of limited oxygen transmissibility (Dk/La). This finding appears to be analogous to the previously reported "central circular clouding" (CCC) with this specific appearance associated with the particulars of the keratoconic cornea-contact lens relation. Estimation of local oxygen transmissibilities suggests that a Dk/L < 3 x 10(-9) may produce this gross clinical sign underneath the lens midperiphery, whereas central Dk/L > or = 6 x 10(-9) may be sufficient to prevent its appearance.
authors.affiliation: Jules Stein Eye Institute, Department of Ophthalmology, UCLA School of Medicine.
authors.forename: B A
authors.initials: BA
authors.lastname: Weissman
mesh_terms: D000328:Adult; D003261:Contact Lenses / Q000009:adverse effects*; D015715:Corneal Edema / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000150:complications* / Q000628:therapy; D008875:Middle Aged; D010100:Oxygen
chemical_list: D010100:Oxygen