Skip to main content
Journal of Refractive Surgery, 2010;26(10):786–795
Published Online:https://doi.org/10.3928/1081597X-20100921-04Cited by:19

Abstract

Purpose:

The outcome of ultrashort pulse laser surgery of the cornea is strongly influenced by the light scattering properties of the tissue, for which little data are available. The purpose of the present study is to provide quantitative values for light scattering and its relation to the degree of edema.

Methods:

An experimental optical measuring setup based on confocal geometry was used to measure the unscattered and scattered fractions of light transmitted by eye bank corneas presenting various degrees of edema. From these measurements, the effective light penetration depth in the cornea was calculated as a function of wavelength.

Results:

Corneal transparency depends on the pathological state of the cornea and on wavelength. It may be predicted as a function of corneal thickness, ie, the degree of edema. In healthy and edematous cornea, the percentage of scattered light decreases with increasing wavelength. The total penetration depths at the wavelengths of ∼1050 nm (which is used in typical clinical systems) and 1650 nm (which is recommended for future devices) are comparable; however, the former is limited by scattering, which degrades the laser beam quality, whereas the latter is only limited by optical absorption, which may be compensated for.

Conclusions:

The use of longer wavelengths should help improve the surgical outcome in ultrashort pulse laser surgery of the cornea when working on pathological tissue. A wavelength of approximately 1650 nm appears to be a good compromise, as it allows for reduced light scattering while keeping optical absorption reasonably low.

  • 1.Soong HK, Katz DG, Farjo AA, Sugar A, Meyer RF. Central lamellar keratoplasty for optical indications. Cornea. 1999; 18(3):249–256.10.1097/00003226-199905000-00001

    > Crossref MedlineGoogle Scholar
  • 2.Stern D, Schoenlein RW, Puliafito CA, Dobi ET, Birngruber R, Fujimoto JG. Corneal ablation by nanosecond, picosecond, and femtosecond lasers at 532 and 625 nm. Arch Ophthalmol. 1989; 107(4):587–592.

    > Crossref MedlineGoogle Scholar
  • 3.Roach WP, Rogers ME, Rockwell BA, Boppart SA, Stein CD, Bramlette CM. Ultrashort laser pulse effects in ocular and related media. Aviat Space Environ Med. 1994; 65(5 Suppl):100–107.

    > MedlineGoogle Scholar
  • 4.Juhasz T, Kastis GA, Suarez C, Bor Z, Bron WE. Time-resolved observations of shock waves and cavitation bubbles generated by femtosecond laser pulses in corneal tissue and water. Lasers Surg Med. 1996; 19(1):23–31.10.1002/(SICI)1096-9101(1996)19:1<23::AID-LSM4>3.0.CO;2-S

    > Crossref MedlineGoogle Scholar
  • 5.Sacks ZS, Kurtz RM, Juhasz T, Mourau GA. High precision subsurface photodisruption in human sclera. J Biomed Opt. 2002; 7(3):442–450.10.1117/1.1482381

    > Crossref MedlineGoogle Scholar
  • 6.Sacks ZS, Kurtz RM, Juhasz T, Spooner G, Mouroua GA. Sub-surface photodisruption in human sclera: wavelength dependence. Ophthalmic Surg Lasers Imaging. 2003; 34(2):104–113.

    > LinkGoogle Scholar
  • 7.Soong HK, Malta JB. Femtosecond lasers in ophthalmology. Am J Ophthalmol. 2009; 147(2):189–197.10.1016/j.ajo.2008.08.026

    > Crossref MedlineGoogle Scholar
  • 8.Plamann K, Aptel F, Arnold CL, Courjaud A, Crotti C, Deloison F, Druon F, Georges P, Hanna M, Legeais JM, Morin F, Mottay É, Nuzzo V, Peyrot DA, Savoldelli M. Ultrashort pulse laser surgery of the cornea and the sclera. Journal of Optics. 2010; 12(8). doi:10.1088/2040-8978/12/8/084002.10.1088/2040-8978/12/8/084002

    > CrossrefGoogle Scholar
  • 9.Nuzzo V, Plamann K, Savoldelli M, Merano M, Donate D, Albert O, Gardeazábal Rodríguez PF, Mourou G, Legeais JM. In situ monitoring of second-harmonic generation in human corneas to compensate for femtosecond laser pulse attenuation in keratoplasty. J Biomed Opt. 2007; 12(6):064032.10.1117/1.2811951

    > Crossref MedlineGoogle Scholar
  • 10.Maurice DM. The structure and transparency of the cornea. J Physiol. 1957; 136(2):263–286.

    > Crossref MedlineGoogle Scholar
  • 11.Hart RW, Farrell RA. Light scattering in the cornea. J Opt Soc Am. 1969; 59(6):766–774.10.1364/JOSA.59.000766

    > Crossref MedlineGoogle Scholar
  • 12.Maurice DM. The transparency of the corneal stroma. Vision Res. 1970; 10(1):107–108.10.1016/0042-6989(70)90068-4

    > Crossref MedlineGoogle Scholar
  • 13.Feuk T. On the transparency of the stroma in the mammalian cornea. IEEE Trans Biomed Eng. 1970; 17(3):186–190.10.1109/TBME.1970.4502732

    > Crossref MedlineGoogle Scholar
  • 14.Feuk T. The wavelength dependence of scattered light intensity in rabbit corneas. IEEE Trans Biomed Eng. 1971; 18(2):92–96.10.1109/TBME.1971.4502808

    > Crossref MedlineGoogle Scholar
  • 15.Farrell RA, McCally RL, Tatham PE. Wave-length dependencies of light scattering in normal and cold swollen rabbit corneas and their structural implications. J Physiol. 1973; 233(3):589–612.

    > Crossref MedlineGoogle Scholar
  • 16.Farrell RA, McCally RL. On corneal transparency and its loss with swelling. J Opt Soc Am. 1976; 66(4):342–345.10.1364/JOSA.66.000342

    > Crossref MedlineGoogle Scholar
  • 17.Hart RW, Farrell RA. On the theory of the spatial organization of macromolecules in connective tissue. Bull Math Biophys. 1969; 31(4):727–760.10.1007/BF02477784

    > Crossref MedlineGoogle Scholar
  • 18.Hart RW, Farrell R. Structural theory of the swelling pressure of corneal stroma in saline. Bull Math Biophys. 1971; 33(2):165–186.10.1007/BF02579470

    > Crossref MedlineGoogle Scholar
  • 19.Benedek G. Theory of transparency of the eye. Appl Opt. 1971; 10(3):459–473.10.1364/AO.10.000459

    > Crossref MedlineGoogle Scholar
  • 20.Cox JL, Farrell RA, Hart RW, Langham ME. The transparency of the mammalian cornea. J Physiol. 1970; 210(3):601–616.

    > Crossref MedlineGoogle Scholar
  • 21.Farrell RA, McCally RL. In: , Albert DM, Jakobiec FA, Azar DT, Gragoudas ES, eds. Principles and Practice of Ophthalmology. 2nd ed. Philadelphia, PA: WB Saunders; 2000.

    > Google Scholar
  • 22.Smith TB. Modeling corneal transparency. American Journal of Physics. 2007; 75(7):588–596.10.1119/1.2730840

    > CrossrefGoogle Scholar
  • 23.van de Hulst HC. Light Scattering by Small Particles. New York, NY: New Dover Publications Inc; 1984.

    > Google Scholar
  • 24.Kokhanovsky AA. Light Scattering Media Optics. 3rd ed. Berlin, German: Springer; 2004.

    > Google Scholar
  • 25.Bohren CF, Huffman DR. Absorption and Scattering of Light by Small Particles. Berlin, Germany: Wiley VCH Verlag: 2004.

    > Google Scholar
  • 26.Jester JV, Petroll WM, Cavanagh HD. Corneal stromal wound healing in refractive surgery: the role of myofibroblasts. Prog Ret Eye Res. 1999; 18(3):311–356.10.1016/S1350-9462(98)00021-4

    > Crossref MedlineGoogle Scholar
  • 27.Boettner EA, Wolter JR. Transmission of the ocular media. Invest Ophthalmol Vis Sci. 1962; 1:776–783.

    > Google Scholar
  • 28.van den Berg TJ, Tan KE. Light transmittance of the human cornea from 320 to 700 nm for different ages. Vision Res. 1994; 34(11):1453–1456.10.1016/0042-6989(94)90146-5

    > Crossref MedlineGoogle Scholar
  • 29.Del Val JA, Barrero S, Yáez B, Merayo J, Aparicio JA, González VR, Pastor JC, Mar S. Experimental measurement of corneal haze after excimer laser keratectomy. Appl Opt. 2001; 40(10):1727–1734.10.1364/AO.40.001727

    > Crossref MedlineGoogle Scholar
  • 30.de Brouwere D, Ginis H, Kymionis G, Naoumidi I, Pallikaris I. Forward scattering properties of corneal haze. Optom Vis Sci. 2008; 85(9):843–848.10.1097/OPX.0b013e31818527b4

    > Crossref MedlineGoogle Scholar
  • 31.Møller-Pedersen T. Keratocyte reflectivity and corneal haze. Exp Eye Res. 2004; 78(3):553–560.10.1016/S0014-4835(03)00208-2

    > Crossref MedlineGoogle Scholar
  • 32.Niemz MH. Laser-Tissue Interactions: Fundamentals and Applications. 3rd ed. Berlin, Germany: Springer-Verlag; 2003.

    > Google Scholar
  • 33.Wolf AH, Welge-Lüssen UC, Priglinger S, Kook D, Grueterich M, Hartmann K, Kampik A, Neubauer AS. Optimizing the deswelling process of organ-cultured corneas. Cornea. 2009; 28(5):524–529.10.1097/ICO.0b013e3181901dde

    > Crossref MedlineGoogle Scholar
  • 34.Pels L. Organ culture: the method of choice for preservation of human donor corneas. Br J Ophthalmol. 1997; 81(7):523–525.10.1136/bjo.81.7.523

    > Crossref MedlineGoogle Scholar
  • 35.EEBA European Eye Bank Directory. 15th ed. Amsterdam, The Netherlands; 2007.

    > Google Scholar
  • 36.Pels E, Beele H, Claerhout I. Eye bank issues: II. Preservation techniques: warm versus cold storage. Int Ophthalmol. 2008; 28(3):155–163.10.1007/s10792-007-9086-1

    > Crossref MedlineGoogle Scholar
  • 37.Jeng BH. Preserving the cornea: corneal storage media. Curr Opin Ophthalmol. 2006; 17(4):332–337.10.1097/01.icu.0000233950.63853.88

    > Crossref MedlineGoogle Scholar
  • 38.Tuchin VV. Tissue Optics: Light Scattering Methods and Instruments for Medical Diagnostics. 2nd ed. Bellingham, WA: SPIE Press; 2007.

    > CrossrefGoogle Scholar
  • 39.Nuzzo V, Savoldelli M, Legeais J-M, Plamann K. Self-focusing and spherical aberrations in corneal tissue during photodisruption by femtosecond laser. J Biomed Opt. 2010; 15(3):038003.10.1117/1.3455507

    > Crossref MedlineGoogle Scholar
  • 40.Morin F, Druon F, Hanna M, Georges P. Microjoule femtosecond fiber laser at 1.6 microm for corneal surgery applications. Opt Lett. 2009; 34(13):1991–1993.10.1364/OL.34.001991

    > Crossref MedlineGoogle Scholar

We use cookies on this site to enhance your user experience. For a complete overview of all the cookies used, please see our privacy policy.

×