Abstract
An understanding of the physical basis of corneal transparency has been a subject of interest amongst physicists, basic scientists and ophthalmologists. Impairment of corneal clarity is a significant cause of visual morbidity worldwide. Several highly mathematical treatises have been presented in support of different theories of corneal transparency in the normal cornea relating structure to function, particularly in the years since the advent of the electron microscope, which has brought about a much greater understanding of corneal ultrastructure. This review presents the concepts that underpin the theories of corneal transparency.
Similar content being viewed by others
Article PDF
References
Candia OA . Fluid and electrolyte transport in corneal transparency. Mt Sinai J Med 1980; 47: 74–9.
Duane TD . The steady state of corneal hydration. Am J Ophthalmol 1942; 32: 203–7.
Craig AS, Robertson JG, Parry DAD . Preservation of corneal collagen structure using low-temperature procedures for electron microscopy. J Ultrastruct Mol Struct Res 1987; 96: 172–5.
Sayers Z, Koch MHJ, Whitburn SB, Meek KM, Elliott GF, Harmsen A . Synchrotron X-ray diffraction study of the corneal stroma. J Mol Biol 1982; 160: 593–607.
Gray's anatomy. 37th ed. London: Churchill Livingstone, 1989: 1181–5.
Klyce SD, Beuerman RW . Structure and function of the cornea. In: Kaufman HE, Barron BA, McDonald MB, Waltman SR, editors. The cornea. 1987: 1–47.
Jakus MA . The fine structure of the human cornea. In: Smelser GK, editor. VII International Congress of Anatomists. New York: Academic Press, 1961: 343–66.
Harris JE . Factors influencing corneal hydration. Invest Ophthalmol Vis Sci 1962; 1: 151–7.
Hart WM . Hydration and transparency of the cornea. Am J Ophthalmol 1947; 30: 1022–4.
Borcherding MS, Blacik LJ, Sittig RA, Bizzell JW, Breen M, Weinstein HG . Proteoglycans and collagen fibre organisation in human corneoscleral tissue. Exp Eye Res 1975; 21: 57–70.
Davson H . The cornea. In: Physiology of the eye. 5th ed. London: Macmillan Press, 1990: 105–38.
Davson H . The hydration of the cornea. Biochem J 1955; 59: 24–8.
Potts AM, Friedman BC . Studies on corneal transparency. Am J Ophthalmol 1959; 48: 480–7.
Boettner EA, Wolter JR . Transmission of the ocular media. Invest Ophthalmol Vis Sci 1962; 1: 776–83.
Duke-Elder S . Textbook of ophthalmology, vol 1. Biological optics; the absorption of radiant energy by the ocular tissues. London: Kimpton:1932: 809–18.
Fuchs's textbook of ophthalmology. 8th ed. USA: Duane Lippincott, 1919: 72–3.
Leber T . The circulation and nutritional relations to the eye. In: Graefe-Saemisch Handbuch der Gesampten Augenheilkunde. Vol. 2. Leipzig: Engelmann, 1903: 101–491.
Bowman W . In: Lectures on the parts concerned in the operations on the eye and on the structure of the retina. London: Longman, Brown, Green and Longman's, 1849: 1–143.
Kinsey VE, Cogan DG . The cornea: physiological aspects. Arch Ophthalmol 1942; 28: 661–9.
Aurell G, Holmgren H . On the metachromatic staining of corneal tissue and some observations on its transparency. Acta Ophthalmol (Copenh) 1953; 31: 1–27.
Smith JW . The transparency of the corneal stroma. Vision Res 1969; 9: 393–6.
Bettelheim FA, Kumbar M . An interpretation of small angle light scattering patterns of human cornea. Invest Ophthalmol Vis Sci 1977; 16: 233–6.
Bettelheim FA, Magrill R . Small angle light scattering patterns of corneas of different species. Invest Ophthalmol Vis Sci 1977; 16: 236–40.
Kikkawa Y . Diffraction spectra produced by rabbit cornea. Jpn J Physiol 1958; 8: 138–47.
Kikkawa Y . Light scattering studies of the rabbit cornea. Jpn J Physiol 1960; 10: 292–302.
Maurice DM . The structure and transparency of the cornea. J Physiol (Lond) 1957; 136: 263–86.
McCally RL, Farrell AR . Structural implications of small angle light scattering from cornea. Exp Eye Res 1982; 34: 99–113.
Stanworth A, Naylor EJ . Polarised light studies of the cornea. I. The isolated cornea. J Exp Biol 1953; 30: 160–3.
Caspersson T, Engström A . The transparency of corneal tissue. Nord Med 1946; 30: 1279–82.
Schwarz W . Electronenmikroskopische Untersuchun-gen iiber den Aufbau der Sklera und der Cornea des Menschen. Z Zellforsch 1953; 38: 26–49.
Davson H . Anatomy and physiology of the cornea. In: Rycroft BW, editor. Corneal grafts. London: Butter-worth, 1955: 31–5.
Cox JL, Farrell RA, Hart RW, Langham ME . The transparency of the mammalian cornea. J Physiol (Lond) 1970; 210: 601–16.
Schwarz W, Graf Keyserling K . Über die Feinstruktur der menschlichen Cornea, mit besonderer Berücksich-tigung des Problems der Transparenz. Z Zellforsch 1966; 73: 540–8.
Goldman JN, Benedek GB . The relationship between morphology and transparency in the non-swelling corneal stroma of the shark. Invest Ophthalmol Vis Sci 1967; 6: 574–600.
Hart RW, Farrell RA . Light scattering in the cornea. J Opt Soc Am 1969; 59: 766–76.
Potts AM . Some aspects of the interrelation between corneal hydration and transparency. Invest Ophthalmol Vis Sci 1962; 1: 163–9.
Aurell G, Holmgren H . Metachromasia of the cornea, with special reference to the question of transparency. Nord Med 1946; 30: 1277–9.
Goldman JN, Benedek GB, Dohlman CH, Kravitt B . Structural alterations affecting transparency in swollen human corneas. Invest Ophthalmol Vis Sci 1968; 7: 501–19.
Benedek GB . Theory of transparency of the eye. Appl Opt 1971; 10: 459–73.
Champney DC . Fourier transforms and their physical applications. London: Academic Press, 1973.
Feuk T . On the transparency of the stroma in the mammalian cornea. IEEE Trans Biomed Eng 1970; 17: 186–90.
Farrell RA, McCally RL, Tatham PE . Wavelength dependencies of light scattering in normal and cold swollen rabbit corneas and their structural implications. J Physiol (Lond) 1973; 233: 589–612.
Naylor EJ . Polarised light studies of corneal structure. Br J Ophthalmol 1953; 37: 77–84.
Gallagher B, Maurice D . Striations of light scattering in the corneal stroma. J Ultrastruct Mol Struct Res 1977; 61: 100–14.
McCally RL, Farrell AR . The depth dependence of light scattering from the normal rabbit cornea. Exp Eye Res 1976; 23: 69–81.
Meek KM, Blamires T, Elliott GF, Gyi TJ, Nave C . The organisation of collagen fibrils in the human corneal stroma: a synchroton X-ray diffraction study. Current Eye Res 1987; 6: 841–6.
Komai Y, Ushiki T . The three dimensional organisation of collagen fibrils in the human cornea and sclera. Invest Ophthalmol Vis Sci 1991; 32: 2244–58.
Vaezy S, Clark JI . A quantitative analysis of transparency in the human sclera and cornea using Fourier methods. J Microsc 1990; 163: 85–94.
Beems EM, van Best JA . Light transmission of the cornea in whole human eyes. Exp Eye Res 1990; 50: 393–5.
van Best JA, Bollemeijer JG, Sterk CC . Corneal transmission in whole human eyes. Exp Eye Res 1988; 46: 765–8.
Lerman S . Radiant energy and the eye. New York: Macmillan, 1980: 43–59.
Lerman S . Biophysical aspects of corneal and lenticular transparency. Curr Eye Res 1984; 3: 3–14.
Lindström JI, Feuk T, Tengroth B . The distribution of light scattered from the rabbit' s cornea. Acta Ophthalmol (Copenh) 1973; 51: 656–69.
Olsen T . Light scattering from the human cornea. Invest Ophthalmol Vis Sci 1982; 23: 81–6.
Smith GT, Brown NA, Shun-Shin A . Light scatter from the central human cornea. Eye 1990; 4: 584–8.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Freegard, T. The physical basis of transparency of the normal cornea. Eye 11, 465–471 (1997). https://doi.org/10.1038/eye.1997.127
Issue Date:
DOI: https://doi.org/10.1038/eye.1997.127
Keywords
This article is cited by
-
Corneal densitometry in bilateral keratoconus patients with unilateral corneal Vogt’s striae: a contralateral eye study
International Ophthalmology (2022)
-
Effect of Down syndrome and keratoconus on corneal density and volume: a triple comparative study
Scientific Reports (2020)
-
The healing effect of the collagen-glycosaminoglycan copolymer on corneal thinning
BMC Ophthalmology (2018)
-
Two-year topographic and densitometric outcomes of accelerated (45 mW/cm2) transepithelial corneal cross-linking for keratoconus: a case-control study
BMC Ophthalmology (2018)
-
A viscoelastic anisotropic hyperelastic constitutive model of the human cornea
Biomechanics and Modeling in Mechanobiology (2018)