title: Fate of water in the soft contact lens immediately after lens placement onto the cornea.
abstract: Soft contact lenses presoaked in D2O or H2(17)O were used to examine the movement of water immediately after their placement onto the eye. Two experiments were conducted: (1) the rate of D2O loss from these soft lenses was determined by assaying residual D2O with nuclear magnetic resonance spectroscopy; and (2) the movement of water into/inside the eye was followed by tracking the path of H2(17)O using magnetic resonance imaging. D2O dissipation occurred in two phases: an initial rapid washout (1.25 ml/h) followed by a slower phase (0.13 ml/h). The latter was eliminated by previous contact lens wear. The H2(17)O study showed that once water entered the anterior chamber, it rapidly exchanged with water in the ocular (predominantly iris) circulation (flow rate constant = 0.1/min). It appears that exogenous water, in this case water from the soft lens, ultimately interacts with the ocular circulation. This is one aspect of cornea-soft lens interaction previously unreported.
authors.affiliation: Howe Laboratory of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: H M
authors.initials: HM
authors.lastname: Cheng
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism; D001834:Body Water / Q000378:metabolism; D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000378:metabolism*; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D011817:Rabbits; D014867:Water / Q000378:metabolism*; D014882:Water-Electrolyte Balance
chemical_list: D014867:Water