title: Correlation between corneal and ambient temperature with particular focus on polar conditions.
abstract: OBJECTIVE
  To examine the relationship between human corneal and environmental temperature.
  
  
  METHODS
  An infrared camera was used to measure the corneal surface temperature in a group of healthy volunteers as well as in an experimental setting with donor corneas and an artificial anterior chamber, employing circulating saline at +37°C. Liquid nitrogen was used to obtain a very low temperature in the experimental setting. High ambient temperature measurements were performed in a sauna.
  
  
  RESULTS
  In healthy volunteers, the cornea required at least 20-30 min to adapt to change in ambient temperature. The relationship between corneal and external temperature was relatively linear. At the two extremes, +83°C and -40°C, the corneal temperature was +42°C and +25.1°C, respectively. In the experimental setting, corneal temperature was +24.3°C at air temperature -40°C.
  
  
  CONCLUSIONS
  A rather stable aqueous humour temperature of +37°C and high thermal conductivity of the corneal tissue prevent corneal frostbite even at extremely low ambient temperatures.
authors.affiliation: University of Oslo, Oslo, Norway.|Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.
authors.forename: Jon Klokk
authors.initials: JK
authors.lastname: Slettedal
authors.affiliation: University of Oslo, Oslo, Norway.
authors.forename: Amund
authors.initials: A
authors.lastname: Ringvold
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D001831:Body Temperature / Q000502:physiology*; D003081:Cold Climate; D003080:Cold Temperature; D003315:Cornea / Q000502:physiology*; D004777:Environment; D005260:Female; D064368:Healthy Volunteers; D006358:Hot Temperature; D006801:Humans; D007259:Infrared Rays; D008297:Male; D008875:Middle Aged; D009924:Organ Culture Techniques; D009926:Organ Preservation; D010781:Photography / Q000295:instrumentation; D013814:Thermal Conductivity; D013817:Thermography / Q000295:instrumentation
keywords: cornea; infrared camera; temperature; thermal conductivity