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Br J Ophthalmol. 1996 Dec; 80(12): 1068–1072.
PMCID: PMC505705

Diurnal variations in human corneal thickness.


AIM: To elucidate the diurnal variation in human corneal thickness over a 48 hour period. METHOD: Changes in central corneal thickness were monitored in eight healthy subjects (four male, four female) aged between 10 and 63 years using an ultrasonic pachymeter. Measurements were made over a 48 hour period-immediately before sleep, immediately upon waking and at 15, 30, 45 minutes, 1, 1.5, 2, 2.5, 3 hours, and at 2 hour intervals thereafter throughout the remainder of each day. RESULTS: The mean corneal thickness for the group (SD) was 546 (14) microns, with a mean overnight increase of 5.5% (2.9%) (range 1.9-12.6%) and a maximum diurnal increase of 7.2% (2.8%) (range 2.1-14.3%). Individual differences in the extent of diurnal and overnight variation occurred within the group. For three subjects, the first reading taken on waking was not the highest and corneal thickness continued to increase. CONCLUSION: These data confirm an increase of corneal thickness during sleep, but also reveal considerable variation during waking hours. Thus, the overnight changes in corneal thickness are not truly representative of diurnal variations in human corneal thickness and, in fact, much greater diurnal variation occurs than the 3.0-4.4% previously reported.

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Selected References

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  • Hedbys BO, Mishima S. The thickness-hydration relationship of the cornea. Exp Eye Res. 1966 Jul;5(3):221–228. [PubMed]
  • Mandell RB, Polse KA, Brand RJ, Vastine D, Demartini D, Flom R. Corneal hydration control in Fuchs' dystrophy. Invest Ophthalmol Vis Sci. 1989 May;30(5):845–852. [PubMed]
  • Insler MS, Baumann JD. Corneal thinning syndromes. Ann Ophthalmol. 1986 Feb;18(2):74–75. [PubMed]
  • Weston BC, Bourne WM, Polse KA, Hodge DO. Corneal hydration control in diabetes mellitus. Invest Ophthalmol Vis Sci. 1995 Mar;36(3):586–595. [PubMed]
  • Huff JW. Contact lens-induced edema in vitro. Pharmacology and metabolic considerations. Invest Ophthalmol Vis Sci. 1991 Feb;32(2):346–353. [PubMed]
  • Cheng H, Bates AK, Wood L, McPherson K. Positive correlation of corneal thickness and endothelial cell loss. Serial measurements after cataract surgery. Arch Ophthalmol. 1988 Jul;106(7):920–922. [PubMed]
  • Klyce SD. Stromal lactate accumulation can account for corneal oedema osmotically following epithelial hypoxia in the rabbit. J Physiol. 1981 Dec;321:49–64. [PMC free article] [PubMed]
  • Johnson MH, Boltz RL, Godio LB. Deswelling of the cornea after hypoxia. Am J Optom Physiol Opt. 1985 Nov;62(11):768–773. [PubMed]
  • Efron N, Carney LG. Oxygen levels beneath the closed eyelid. Invest Ophthalmol Vis Sci. 1979 Jan;18(1):93–95. [PubMed]
  • Holden BA, Mertz GW, McNally JJ. Corneal swelling response to contact lenses worn under extended wear conditions. Invest Ophthalmol Vis Sci. 1983 Feb;24(2):218–226. [PubMed]
  • Frampton P, Da Rin D, Brown B. Diurnal variation of intraocular pressure and the overriding effects of sleep. Am J Optom Physiol Opt. 1987 Jan;64(1):54–61. [PubMed]
  • Chan-Ling T, Efron N, Holden BA. Diurnal variation of corneal thickness in the cat. Invest Ophthalmol Vis Sci. 1985 Jan;26(1):102–105. [PubMed]
  • Madigan MC, Gillard-Crewther S, Kiely PM, Crewther DP, Brennan NA, Efron N, Holden BA. Corneal thickness changes following sleep and overnight contact lens wear in the primate (Macaca fascicularis). Curr Eye Res. 1987 Jun;6(6):809–815. [PubMed]
  • Mandell RB, Fatt I. Thinning of the human cornea on awakening. Nature. 1965 Oct 16;208(5007):292–293. [PubMed]
  • Gerstman DR. The biomicroscope and Vickers image splitting eyepiece applied to the diurnal variation in human central corneal thickness. J Microsc. 1972 Dec;96(3):385–388. [PubMed]
  • Kiely PM, Carney LG, Smith G. Diurnal variations of corneal topography and thickness. Am J Optom Physiol Opt. 1982 Dec;59(12):976–982. [PubMed]
  • Mertz GW. Overnight swelling of the living human cornea. J Am Optom Assoc. 1980 Mar;51(3):211–214. [PubMed]
  • Shiono T, Asano Y, Hashimoto T, Mizuno K. Temporary corneal oedema after acute intake of alcohol. Br J Ophthalmol. 1987 Jun;71(6):462–465. [PMC free article] [PubMed]
  • Kiely PM, Carney LG, Smith G. Menstrual cycle variations of corneal topography and thickness. Am J Optom Physiol Opt. 1983 Oct;60(10):822–829. [PubMed]
  • Bourassa S, Benjamin WJ, Boltz RL. Effect of humidity on the deswelling function of the human cornea. Curr Eye Res. 1991 Jun;10(6):493–500. [PubMed]
  • Mishima S, Hedbys BO. The permeability of the corneal epithelium and endothelium to water. Exp Eye Res. 1967 Jan;6(1):10–32. [PubMed]
  • Klyce SD, Crosson CE. Transport processes across the rabbit corneal epithelium: a review. Curr Eye Res. 1985 Apr;4(4):323–331. [PubMed]

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