title: Dielectric properties of ocular tissues in the supercooled and frozen states.
abstract: Values of the relative permittivity and conductivity of the rabbit retina and lens have been measured between 10 MHz and 10 GHz over the temperature range 20 to -20 degrees C. As the temperature was lowered from 20 degrees C the dielectric parameters changed smoothly until -9 degrees C where freezing occurred. At this temperature a sharp transition was observed in both conductivity and relative permittivity, the latter falling to a value of below 10 over most of the frequency range. Analysis shows that this is due to the unfreezable water, from which a value of lens hydration is calculated. This value agrees with that obtained previously at 37 degrees C using conventional dielectric mixture theory, but the associated margin of error is much smaller.
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004553:Electric Conductivity; D005615:Freezing; D007908:Lens, Crystalline / Q000502:physiology*; D009928:Organ Specificity; D011817:Rabbits; D012160:Retina / Q000502:physiology*; D013696:Temperature