Abstract

We describe noninvasive techniques to optimize reflectometry measurements, particularly retinal densitometry, which measures the photopigment density difference. With these techniques unwanted scattered light is greatly reduced, and the retina is visualized during measurements. Thus results may be compared for each retinal location, and visible artifacts are minimized. The density difference measurements of the cone photopigment depend on the optical configuration of the apparatus. The cone photopigment density difference is greatest near the fovea and for most observers decreases rapidly with eccentricity. A research version for reflectometry and psychophysics of the scanning laser ophthalmoscope is described.

© 1992 Optical Society of America

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  1. A. E. Elsner, A. H. Jalkh, J. J. Weiter, “New devices for retinal imaging and function evaluation,” in Practical Atlas of Retinal Disease and Therapy, W. Freeman, ed. (Raven, New York, to be published).
  2. J. E. Nasemann, R. O. W. Burk, eds., Laser Scanning Ophthalmoscopy and Tomography (Quintesenz-Verlag, Berlin, 1990).
  3. J. E. E. Keunan, “Densitometry in diseases and senescence of the human retina,” dissertation (State University of Utrecht, Utrecht, 1988) is an anthology of published articles and work in progress at the time. It is available from the author.
  4. A. E. Elsner, ed., Laser Sanning Ophthalmoscopy, Tomography, and Microscopy (Plenum, New York, to be published).
  5. A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.
  6. A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment densitometry with a scanning laser ophthalmoscope,” in 1988 Annual Meeting, Vol. II of 1988 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1988), paper WY3. These first results (also Ref. 5) were for rod and cone photopigments and different instrumentation and technique.
  7. D. van Norren, “Towards improved instrumentation for retinal densitometry,” in Research in Retinitis Pigmentosa, E. Zrenner, H. Krastel, H.-H. Boebel, eds. (Pergamon, Oxford, 1987), Vol. 62, pp. 177–178; D. van Norren, J. van de Kraats, “Imaging retinal densitometry with a confocal scanning laser ophthalmoscope,” Vision Res. 29, 1825–1830 (1989).
    [CrossRef] [PubMed]
  8. A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).
  9. A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.
  10. A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).
  11. A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.
  12. A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.
  13. W. A. H. Rushton, “Kinetics of cone pigments measured objectively on the living human fovea,” Ann. N.Y. Acad. Sci. 74, 291–304 (1958).
    [CrossRef]
  14. H. Ripps, R. A. Weale, “Cone pigments in the normal human fovea,” Vision Res. 3, 531–543 (1963); “Photo-labile changes and the directional sensitivity of the human fovea,” J. Physiol. 173, 57–64 (1964); “Analysis of foveal densitometry,” Nature (London) 205, 52–56 (1965).
    [CrossRef] [PubMed]
  15. W. A. H. Rushton, G. H. Henry, “Bleaching and regeneration of cone pigments in man,” Vision Res. 8, 617–631 (1968).
    [CrossRef] [PubMed]
  16. M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
    [CrossRef] [PubMed]
  17. I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.
  18. D. van Norren, J. van der Kraats, “A continuously recording retinal densitometer,” Vision Res. 21, 897–905 (1981).
    [CrossRef] [PubMed]
  19. M. Alpern, D. H. Krantz, “Visual pigment kinetics in abnormalities of the uvea–retinal epithelium interface in man,” Invest. Ophthalmol. Vis. Sci. 20, 183–203 (1981).
    [PubMed]
  20. P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
    [CrossRef] [PubMed]
  21. V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
    [CrossRef] [PubMed]
  22. G. J. van Meel, D. van Norren, “Foveal densitometry in retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 24, 1123–1130 (1983).
    [PubMed]
  23. C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).
  24. G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
    [PubMed]
  25. D. J. Faulkner, C. M. Kemp, “Human rhodopsin measurement using a T.V.-based imaging fundus reflectometer,” Vision Res. 24, 221–231 (1984).
    [CrossRef] [PubMed]
  26. P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
    [CrossRef] [PubMed]
  27. A. B. Fulton, R. M. Hansen, “The relationship of retinal sensitivity and rhodopsin in human infants,” Vision Res. 27, 697–704 (1987).
    [CrossRef] [PubMed]
  28. A. B. Fulton, R. M. Hansen, “Foveal cone pigments and sensitivity in young patients with Usher’s syndrome,” Am. J. Ophthalmol. 103, 150–160 (1987).
    [PubMed]
  29. L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).
  30. D. van Norren, J. van de Kraats, “Retinal densitometer with the size of a fundus camera,” Vision Res. 29, 369–374 (1989).
    [CrossRef] [PubMed]
  31. H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
    [CrossRef]
  32. P. E. Kilbride, K. M. Keehan, “Visual pigments in the human macula assessed by imaging fundus reflectometry,” Appl. Opt. 29, 1427–1435 (1990).
    [CrossRef] [PubMed]
  33. D. van Norren, L. F. Tiemeijer, “Spectral reflectance of the human eye,” Vision Res. 26, 313–320 (1986).
    [CrossRef] [PubMed]
  34. G. J. van Blokland, “Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo,” Vision Res. 26, 495–500 (1986).
    [CrossRef] [PubMed]
  35. F. C. Delori, K. P. Pflibsen, “Spectral reflectance of the human ocular fundus,” Appl. Opt. 28, 1061–1077 (1989).
    [CrossRef] [PubMed]
  36. R. W. Knighton, S. G. Jacobson, M. I. Roman, “Specular reflection from the surface of the retina,” in Laser Surgery: Advanced Characterization, Theraputics, and Systems, K. Atsumi, N. R. Goldblatt, S. N. Joffe, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1066, 10–17 (1989).
  37. R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).
  38. J.-M. Gorrand, “Reflection characteristics of the human fovea assessed by reflecto-modulometry,” Ophthal. Physiol. Opt. 9, 53–60 (1989).
    [CrossRef]
  39. J.-M. Gorrand, F. Bacin, “Use of reflecto-modulometry to study the optical quality of the inner retina,” Ophthal. Physiol. Opt. 9, 198–204 (1989).
    [CrossRef]
  40. P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).
  41. J.-M. Gorrand, F. C. Delori, “A method for assessing the photoreceptor directionality,” Invest. Ophthalmol. Vis. Sci. 31/4, 425 (1990); S. A. Burns, A. E. Elsner, J. M. Gorrand, M. R. Kreitz, “Variability in color matching, photoreceptor alignment, and the Stiles–Crawford II effect,” in 1991 Annual Meeting, Vol. 17 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), p. 24.
  42. R. W. Webb, G. W. Hughes, F. C. Delori, “Confocal scanning laser ophthalmoscope,” Appl. Opt. 26, 1492–1499 (1987).
    [CrossRef] [PubMed]
  43. A. Plesch, U. Klingbeil, “Optical characteristics of a scanning laser ophthalmoscope,” in New Methods in Microscopy and Low Light Imaging, J. E. Wampler, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1161, 390–398 (1989).
  44. A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.
  45. A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.
  46. F. J. van de Velde, A. E. Jalkh, A. E. Elsner, “Microperimetry with the scanning laser ophthalmoscope,” in Perimetry Update, 1990/1991, R. P. Mills, A. Heijl, eds. (Kugler, Amsterdam, 1991), pp. 93–101; J.-F. Chen, P. L. Lou, A. E. Elsner, R. M. Hansen, H.-M. Cheng, A. B. Fulton, “The effect of refractive error on retinal responses,” Invest. Ophthalmol. Vis. Sci. 32, 929 (1991).
  47. AEM-40 modulators with modified E40ER drivers, IntraAction Corporation, Bellwood, Ill. The AOM must be oriented horizontally, since the Fourier transform of the modulation pulse contains frequencies other than the carrier frequency and thus deflects the beam a little. The horizontal orientation assures that the deflection is equal in the scan direction.
  48. EG&G, RCA C30950E, Spec. 710 (Vaudreuil, Quebec, Canada).
  49. Scanned laser rasters do not have apparent speckle. S. A. Burns, M. R. Kreitz, A. E. Elsner, “Apparatus note: a computer controlled, two color, laser-based optical stimulator for vision research,” Appl. Opt. 30, 2063–2065 (1991).
    [CrossRef] [PubMed]
  50. W. B. Cowan, M. L. Rowell, “Phosphor constancy in color video monitors,” Color Res. Appl. 11, 34–38 (1986).
  51. G. Wyszecki, W. S. Stiles, Color Science (Wiley, New York, 1982).
  52. S. A. Burns, A. E. Elsner, “Color matching at high illuminances: the color match area effect and photopigment bleaching,” J. Opt. Soc. Am. A 2, 916–920 (1985).
    [CrossRef]
  53. G. A. Osterberg, “Topography of the layer of rods and cones in the human retina,” Acta Ophthalmol. 13Suppl. 6, 1 (1935); C. A. Curcio, K. R. Sloan, O. Packer, A. E. Hendrickson, R. E. Kalina, “Distribution of cones in human and monkey retina: individual variability and radial asymmetry,” Science 236, 579–582 (1987); C. A. Curcio, K. R. Sloan, R. E. Kalina, A. E. Hendrickson, “Human photoreceptor topography,” J. Comput. Neurol. 292, 497–523 (1990).
    [CrossRef] [PubMed]

1991 (1)

1990 (3)

P. E. Kilbride, K. M. Keehan, “Visual pigments in the human macula assessed by imaging fundus reflectometry,” Appl. Opt. 29, 1427–1435 (1990).
[CrossRef] [PubMed]

J.-M. Gorrand, F. C. Delori, “A method for assessing the photoreceptor directionality,” Invest. Ophthalmol. Vis. Sci. 31/4, 425 (1990); S. A. Burns, A. E. Elsner, J. M. Gorrand, M. R. Kreitz, “Variability in color matching, photoreceptor alignment, and the Stiles–Crawford II effect,” in 1991 Annual Meeting, Vol. 17 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), p. 24.

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

1989 (8)

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).

D. van Norren, J. van de Kraats, “Retinal densitometer with the size of a fundus camera,” Vision Res. 29, 369–374 (1989).
[CrossRef] [PubMed]

H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
[CrossRef]

F. C. Delori, K. P. Pflibsen, “Spectral reflectance of the human ocular fundus,” Appl. Opt. 28, 1061–1077 (1989).
[CrossRef] [PubMed]

R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).

J.-M. Gorrand, “Reflection characteristics of the human fovea assessed by reflecto-modulometry,” Ophthal. Physiol. Opt. 9, 53–60 (1989).
[CrossRef]

J.-M. Gorrand, F. Bacin, “Use of reflecto-modulometry to study the optical quality of the inner retina,” Ophthal. Physiol. Opt. 9, 198–204 (1989).
[CrossRef]

P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).

1988 (1)

L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).

1987 (3)

R. W. Webb, G. W. Hughes, F. C. Delori, “Confocal scanning laser ophthalmoscope,” Appl. Opt. 26, 1492–1499 (1987).
[CrossRef] [PubMed]

A. B. Fulton, R. M. Hansen, “The relationship of retinal sensitivity and rhodopsin in human infants,” Vision Res. 27, 697–704 (1987).
[CrossRef] [PubMed]

A. B. Fulton, R. M. Hansen, “Foveal cone pigments and sensitivity in young patients with Usher’s syndrome,” Am. J. Ophthalmol. 103, 150–160 (1987).
[PubMed]

1986 (4)

D. van Norren, L. F. Tiemeijer, “Spectral reflectance of the human eye,” Vision Res. 26, 313–320 (1986).
[CrossRef] [PubMed]

G. J. van Blokland, “Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo,” Vision Res. 26, 495–500 (1986).
[CrossRef] [PubMed]

W. B. Cowan, M. L. Rowell, “Phosphor constancy in color video monitors,” Color Res. Appl. 11, 34–38 (1986).

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

1985 (1)

S. A. Burns, A. E. Elsner, “Color matching at high illuminances: the color match area effect and photopigment bleaching,” J. Opt. Soc. Am. A 2, 916–920 (1985).
[CrossRef]

1984 (2)

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

D. J. Faulkner, C. M. Kemp, “Human rhodopsin measurement using a T.V.-based imaging fundus reflectometer,” Vision Res. 24, 221–231 (1984).
[CrossRef] [PubMed]

1983 (4)

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
[CrossRef] [PubMed]

G. J. van Meel, D. van Norren, “Foveal densitometry in retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 24, 1123–1130 (1983).
[PubMed]

C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).

1981 (2)

D. van Norren, J. van der Kraats, “A continuously recording retinal densitometer,” Vision Res. 21, 897–905 (1981).
[CrossRef] [PubMed]

M. Alpern, D. H. Krantz, “Visual pigment kinetics in abnormalities of the uvea–retinal epithelium interface in man,” Invest. Ophthalmol. Vis. Sci. 20, 183–203 (1981).
[PubMed]

1971 (1)

M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
[CrossRef] [PubMed]

1968 (1)

W. A. H. Rushton, G. H. Henry, “Bleaching and regeneration of cone pigments in man,” Vision Res. 8, 617–631 (1968).
[CrossRef] [PubMed]

1963 (1)

H. Ripps, R. A. Weale, “Cone pigments in the normal human fovea,” Vision Res. 3, 531–543 (1963); “Photo-labile changes and the directional sensitivity of the human fovea,” J. Physiol. 173, 57–64 (1964); “Analysis of foveal densitometry,” Nature (London) 205, 52–56 (1965).
[CrossRef] [PubMed]

1958 (1)

W. A. H. Rushton, “Kinetics of cone pigments measured objectively on the living human fovea,” Ann. N.Y. Acad. Sci. 74, 291–304 (1958).
[CrossRef]

1935 (1)

G. A. Osterberg, “Topography of the layer of rods and cones in the human retina,” Acta Ophthalmol. 13Suppl. 6, 1 (1935); C. A. Curcio, K. R. Sloan, O. Packer, A. E. Hendrickson, R. E. Kalina, “Distribution of cones in human and monkey retina: individual variability and radial asymmetry,” Science 236, 579–582 (1987); C. A. Curcio, K. R. Sloan, R. E. Kalina, A. E. Hendrickson, “Human photoreceptor topography,” J. Comput. Neurol. 292, 497–523 (1990).
[CrossRef] [PubMed]

Alpern, M.

M. Alpern, D. H. Krantz, “Visual pigment kinetics in abnormalities of the uvea–retinal epithelium interface in man,” Invest. Ophthalmol. Vis. Sci. 20, 183–203 (1981).
[PubMed]

M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
[CrossRef] [PubMed]

Artal, P.

P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).

Bacin, F.

J.-M. Gorrand, F. Bacin, “Use of reflecto-modulometry to study the optical quality of the inner retina,” Ophthal. Physiol. Opt. 9, 198–204 (1989).
[CrossRef]

Baker, H. D.

H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
[CrossRef]

Bescos, J.

P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).

Burns, S. A.

Scanned laser rasters do not have apparent speckle. S. A. Burns, M. R. Kreitz, A. E. Elsner, “Apparatus note: a computer controlled, two color, laser-based optical stimulator for vision research,” Appl. Opt. 30, 2063–2065 (1991).
[CrossRef] [PubMed]

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).

S. A. Burns, A. E. Elsner, “Color matching at high illuminances: the color match area effect and photopigment bleaching,” J. Opt. Soc. Am. A 2, 916–920 (1985).
[CrossRef]

A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.

A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.

A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment densitometry with a scanning laser ophthalmoscope,” in 1988 Annual Meeting, Vol. II of 1988 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1988), paper WY3. These first results (also Ref. 5) were for rod and cone photopigments and different instrumentation and technique.

A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.

A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.

Cowan, W. B.

W. B. Cowan, M. L. Rowell, “Phosphor constancy in color video monitors,” Color Res. Appl. 11, 34–38 (1986).

Delori, F. C.

J.-M. Gorrand, F. C. Delori, “A method for assessing the photoreceptor directionality,” Invest. Ophthalmol. Vis. Sci. 31/4, 425 (1990); S. A. Burns, A. E. Elsner, J. M. Gorrand, M. R. Kreitz, “Variability in color matching, photoreceptor alignment, and the Stiles–Crawford II effect,” in 1991 Annual Meeting, Vol. 17 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), p. 24.

F. C. Delori, K. P. Pflibsen, “Spectral reflectance of the human ocular fundus,” Appl. Opt. 28, 1061–1077 (1989).
[CrossRef] [PubMed]

R. W. Webb, G. W. Hughes, F. C. Delori, “Confocal scanning laser ophthalmoscope,” Appl. Opt. 26, 1492–1499 (1987).
[CrossRef] [PubMed]

A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.

Elsner, A. E.

Scanned laser rasters do not have apparent speckle. S. A. Burns, M. R. Kreitz, A. E. Elsner, “Apparatus note: a computer controlled, two color, laser-based optical stimulator for vision research,” Appl. Opt. 30, 2063–2065 (1991).
[CrossRef] [PubMed]

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).

S. A. Burns, A. E. Elsner, “Color matching at high illuminances: the color match area effect and photopigment bleaching,” J. Opt. Soc. Am. A 2, 916–920 (1985).
[CrossRef]

F. J. van de Velde, A. E. Jalkh, A. E. Elsner, “Microperimetry with the scanning laser ophthalmoscope,” in Perimetry Update, 1990/1991, R. P. Mills, A. Heijl, eds. (Kugler, Amsterdam, 1991), pp. 93–101; J.-F. Chen, P. L. Lou, A. E. Elsner, R. M. Hansen, H.-M. Cheng, A. B. Fulton, “The effect of refractive error on retinal responses,” Invest. Ophthalmol. Vis. Sci. 32, 929 (1991).

A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.

A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment densitometry with a scanning laser ophthalmoscope,” in 1988 Annual Meeting, Vol. II of 1988 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1988), paper WY3. These first results (also Ref. 5) were for rod and cone photopigments and different instrumentation and technique.

A. E. Elsner, A. H. Jalkh, J. J. Weiter, “New devices for retinal imaging and function evaluation,” in Practical Atlas of Retinal Disease and Therapy, W. Freeman, ed. (Raven, New York, to be published).

A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.

A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.

A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.

Faulkner, D. J.

D. J. Faulkner, C. M. Kemp, “Human rhodopsin measurement using a T.V.-based imaging fundus reflectometer,” Vision Res. 24, 221–231 (1984).
[CrossRef] [PubMed]

C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).

Fishman, G. A.

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.

Fishman, M.

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

Fram, I.

I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.

Fulton, A. B.

A. B. Fulton, R. M. Hansen, “Foveal cone pigments and sensitivity in young patients with Usher’s syndrome,” Am. J. Ophthalmol. 103, 150–160 (1987).
[PubMed]

A. B. Fulton, R. M. Hansen, “The relationship of retinal sensitivity and rhodopsin in human infants,” Vision Res. 27, 697–704 (1987).
[CrossRef] [PubMed]

Gorrand, J.-M.

J.-M. Gorrand, F. C. Delori, “A method for assessing the photoreceptor directionality,” Invest. Ophthalmol. Vis. Sci. 31/4, 425 (1990); S. A. Burns, A. E. Elsner, J. M. Gorrand, M. R. Kreitz, “Variability in color matching, photoreceptor alignment, and the Stiles–Crawford II effect,” in 1991 Annual Meeting, Vol. 17 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), p. 24.

J.-M. Gorrand, “Reflection characteristics of the human fovea assessed by reflecto-modulometry,” Ophthal. Physiol. Opt. 9, 53–60 (1989).
[CrossRef]

J.-M. Gorrand, F. Bacin, “Use of reflecto-modulometry to study the optical quality of the inner retina,” Ophthal. Physiol. Opt. 9, 198–204 (1989).
[CrossRef]

Hansen, R. M.

A. B. Fulton, R. M. Hansen, “The relationship of retinal sensitivity and rhodopsin in human infants,” Vision Res. 27, 697–704 (1987).
[CrossRef] [PubMed]

A. B. Fulton, R. M. Hansen, “Foveal cone pigments and sensitivity in young patients with Usher’s syndrome,” Am. J. Ophthalmol. 103, 150–160 (1987).
[PubMed]

Henderson, R.

H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
[CrossRef]

Henry, G. H.

W. A. H. Rushton, G. H. Henry, “Bleaching and regeneration of cone pigments in man,” Vision Res. 8, 617–631 (1968).
[CrossRef] [PubMed]

Hughes, G. W.

R. W. Webb, G. W. Hughes, F. C. Delori, “Confocal scanning laser ophthalmoscope,” Appl. Opt. 26, 1492–1499 (1987).
[CrossRef] [PubMed]

A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.

Hutman, L. P.

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

Jacobson, S. G.

R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).

C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).

R. W. Knighton, S. G. Jacobson, M. I. Roman, “Specular reflection from the surface of the retina,” in Laser Surgery: Advanced Characterization, Theraputics, and Systems, K. Atsumi, N. R. Goldblatt, S. N. Joffe, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1066, 10–17 (1989).

Jalkh, A. E.

F. J. van de Velde, A. E. Jalkh, A. E. Elsner, “Microperimetry with the scanning laser ophthalmoscope,” in Perimetry Update, 1990/1991, R. P. Mills, A. Heijl, eds. (Kugler, Amsterdam, 1991), pp. 93–101; J.-F. Chen, P. L. Lou, A. E. Elsner, R. M. Hansen, H.-M. Cheng, A. B. Fulton, “The effect of refractive error on retinal responses,” Invest. Ophthalmol. Vis. Sci. 32, 929 (1991).

Jalkh, A. H.

A. E. Elsner, A. H. Jalkh, J. J. Weiter, “New devices for retinal imaging and function evaluation,” in Practical Atlas of Retinal Disease and Therapy, W. Freeman, ed. (Raven, New York, to be published).

Keehan, K. M.

Kemp, C. M.

R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).

D. J. Faulkner, C. M. Kemp, “Human rhodopsin measurement using a T.V.-based imaging fundus reflectometer,” Vision Res. 24, 221–231 (1984).
[CrossRef] [PubMed]

C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).

Keunan, J. E. E.

J. E. E. Keunan, “Densitometry in diseases and senescence of the human retina,” dissertation (State University of Utrecht, Utrecht, 1988) is an anthology of published articles and work in progress at the time. It is available from the author.

Kilbride, P. E.

P. E. Kilbride, K. M. Keehan, “Visual pigments in the human macula assessed by imaging fundus reflectometry,” Appl. Opt. 29, 1427–1435 (1990).
[CrossRef] [PubMed]

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

Klingbeil, U.

A. Plesch, U. Klingbeil, “Optical characteristics of a scanning laser ophthalmoscope,” in New Methods in Microscopy and Low Light Imaging, J. E. Wampler, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1161, 390–398 (1989).

A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.

Knighton, R. W.

R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).

R. W. Knighton, S. G. Jacobson, M. I. Roman, “Specular reflection from the surface of the retina,” in Laser Surgery: Advanced Characterization, Theraputics, and Systems, K. Atsumi, N. R. Goldblatt, S. N. Joffe, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1066, 10–17 (1989).

Krantz, D. H.

M. Alpern, D. H. Krantz, “Visual pigment kinetics in abnormalities of the uvea–retinal epithelium interface in man,” Invest. Ophthalmol. Vis. Sci. 20, 183–203 (1981).
[PubMed]

Kreitz, M. R.

Scanned laser rasters do not have apparent speckle. S. A. Burns, M. R. Kreitz, A. E. Elsner, “Apparatus note: a computer controlled, two color, laser-based optical stimulator for vision research,” Appl. Opt. 30, 2063–2065 (1991).
[CrossRef] [PubMed]

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.

A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.

A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.

Maaseidvaag, F.

M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
[CrossRef] [PubMed]

McCormick, B. H.

I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.

Nordby, K.

L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).

O’Keefe, L. P.

H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
[CrossRef]

Ohba, N.

M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
[CrossRef] [PubMed]

Osterberg, G. A.

G. A. Osterberg, “Topography of the layer of rods and cones in the human retina,” Acta Ophthalmol. 13Suppl. 6, 1 (1935); C. A. Curcio, K. R. Sloan, O. Packer, A. E. Hendrickson, R. E. Kalina, “Distribution of cones in human and monkey retina: individual variability and radial asymmetry,” Science 236, 579–582 (1987); C. A. Curcio, K. R. Sloan, R. E. Kalina, A. E. Hendrickson, “Human photoreceptor topography,” J. Comput. Neurol. 292, 497–523 (1990).
[CrossRef] [PubMed]

Pflibsen, K. P.

Plesch, A.

A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.

A. Plesch, U. Klingbeil, “Optical characteristics of a scanning laser ophthalmoscope,” in New Methods in Microscopy and Low Light Imaging, J. E. Wampler, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1161, 390–398 (1989).

Pokorny, J.

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
[CrossRef] [PubMed]

Rappl, W.

A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.

Read, J. S.

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.

Ripps, H.

H. Ripps, R. A. Weale, “Cone pigments in the normal human fovea,” Vision Res. 3, 531–543 (1963); “Photo-labile changes and the directional sensitivity of the human fovea,” J. Physiol. 173, 57–64 (1964); “Analysis of foveal densitometry,” Nature (London) 205, 52–56 (1965).
[CrossRef] [PubMed]

Roman, M. I.

R. W. Knighton, S. G. Jacobson, M. I. Roman, “Specular reflection from the surface of the retina,” in Laser Surgery: Advanced Characterization, Theraputics, and Systems, K. Atsumi, N. R. Goldblatt, S. N. Joffe, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1066, 10–17 (1989).

Rowell, M. L.

W. B. Cowan, M. L. Rowell, “Phosphor constancy in color video monitors,” Color Res. Appl. 11, 34–38 (1986).

Rushton, W. A. H.

W. A. H. Rushton, G. H. Henry, “Bleaching and regeneration of cone pigments in man,” Vision Res. 8, 617–631 (1968).
[CrossRef] [PubMed]

W. A. H. Rushton, “Kinetics of cone pigments measured objectively on the living human fovea,” Ann. N.Y. Acad. Sci. 74, 291–304 (1958).
[CrossRef]

Santamaria, J.

P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).

Schroedel, C.

A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.

Schwarz, R.

A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.

Sharpe, L. T.

L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).

Smith, V. C.

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
[CrossRef] [PubMed]

Stiles, W. S.

G. Wyszecki, W. S. Stiles, Color Science (Wiley, New York, 1982).

Tiemeijer, L. F.

D. van Norren, L. F. Tiemeijer, “Spectral reflectance of the human eye,” Vision Res. 26, 313–320 (1986).
[CrossRef] [PubMed]

Timberlake, G. T.

A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.

van Blokland, G. J.

G. J. van Blokland, “Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo,” Vision Res. 26, 495–500 (1986).
[CrossRef] [PubMed]

van de Kraats, J.

D. van Norren, J. van de Kraats, “Retinal densitometer with the size of a fundus camera,” Vision Res. 29, 369–374 (1989).
[CrossRef] [PubMed]

van de Velde, F. J.

F. J. van de Velde, A. E. Jalkh, A. E. Elsner, “Microperimetry with the scanning laser ophthalmoscope,” in Perimetry Update, 1990/1991, R. P. Mills, A. Heijl, eds. (Kugler, Amsterdam, 1991), pp. 93–101; J.-F. Chen, P. L. Lou, A. E. Elsner, R. M. Hansen, H.-M. Cheng, A. B. Fulton, “The effect of refractive error on retinal responses,” Invest. Ophthalmol. Vis. Sci. 32, 929 (1991).

van der Kraats, J.

D. van Norren, J. van der Kraats, “A continuously recording retinal densitometer,” Vision Res. 21, 897–905 (1981).
[CrossRef] [PubMed]

van Meel, G. J.

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

G. J. van Meel, D. van Norren, “Foveal densitometry in retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 24, 1123–1130 (1983).
[PubMed]

van Norren, D.

D. van Norren, J. van de Kraats, “Retinal densitometer with the size of a fundus camera,” Vision Res. 29, 369–374 (1989).
[CrossRef] [PubMed]

L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).

D. van Norren, L. F. Tiemeijer, “Spectral reflectance of the human eye,” Vision Res. 26, 313–320 (1986).
[CrossRef] [PubMed]

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

G. J. van Meel, D. van Norren, “Foveal densitometry in retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 24, 1123–1130 (1983).
[PubMed]

V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
[CrossRef] [PubMed]

D. van Norren, J. van der Kraats, “A continuously recording retinal densitometer,” Vision Res. 21, 897–905 (1981).
[CrossRef] [PubMed]

D. van Norren, “Towards improved instrumentation for retinal densitometry,” in Research in Retinitis Pigmentosa, E. Zrenner, H. Krastel, H.-H. Boebel, eds. (Pergamon, Oxford, 1987), Vol. 62, pp. 177–178; D. van Norren, J. van de Kraats, “Imaging retinal densitometry with a confocal scanning laser ophthalmoscope,” Vision Res. 29, 1825–1830 (1989).
[CrossRef] [PubMed]

Weale, R. A.

H. Ripps, R. A. Weale, “Cone pigments in the normal human fovea,” Vision Res. 3, 531–543 (1963); “Photo-labile changes and the directional sensitivity of the human fovea,” J. Physiol. 173, 57–64 (1964); “Analysis of foveal densitometry,” Nature (London) 205, 52–56 (1965).
[CrossRef] [PubMed]

Webb, R. H.

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).

A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.

A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment densitometry with a scanning laser ophthalmoscope,” in 1988 Annual Meeting, Vol. II of 1988 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1988), paper WY3. These first results (also Ref. 5) were for rod and cone photopigments and different instrumentation and technique.

Webb, R. W.

Weiter, J. J.

A. E. Elsner, A. H. Jalkh, J. J. Weiter, “New devices for retinal imaging and function evaluation,” in Practical Atlas of Retinal Disease and Therapy, W. Freeman, ed. (Raven, New York, to be published).

A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.

Wyszecki, G.

G. Wyszecki, W. S. Stiles, Color Science (Wiley, New York, 1982).

Acta Ophthalmol. (1)

G. A. Osterberg, “Topography of the layer of rods and cones in the human retina,” Acta Ophthalmol. 13Suppl. 6, 1 (1935); C. A. Curcio, K. R. Sloan, O. Packer, A. E. Hendrickson, R. E. Kalina, “Distribution of cones in human and monkey retina: individual variability and radial asymmetry,” Science 236, 579–582 (1987); C. A. Curcio, K. R. Sloan, R. E. Kalina, A. E. Hendrickson, “Human photoreceptor topography,” J. Comput. Neurol. 292, 497–523 (1990).
[CrossRef] [PubMed]

Am. J. Ophthalmol. (2)

G. J. van Meel, V. C. Smith, J. Pokorny, D. van Norren, “Foveal densitometry in central serous choroidopathy,” Am. J. Ophthalmol. 98, 359–368 (1984).
[PubMed]

A. B. Fulton, R. M. Hansen, “Foveal cone pigments and sensitivity in young patients with Usher’s syndrome,” Am. J. Ophthalmol. 103, 150–160 (1987).
[PubMed]

Ann. N.Y. Acad. Sci. (1)

W. A. H. Rushton, “Kinetics of cone pigments measured objectively on the living human fovea,” Ann. N.Y. Acad. Sci. 74, 291–304 (1958).
[CrossRef]

Appl. Opt. (4)

Arch. Ophthalmol. (1)

P. E. Kilbride, M. Fishman, G. A. Fishman, L. P. Hutman, “Foveal cone pigment density difference and reflectance in retinitis pigmentosa,” Arch. Ophthalmol. 104, 220–224 (1986).
[CrossRef] [PubMed]

Clin. Vision Sci. (1)

L. T. Sharpe, D. van Norren, K. Nordby, “Pigment regeneration, visual adaptation and spectral sensitivity in the achromat,” Clin. Vision Sci. 3, 9–17 (1988).

Color Res. Appl. (1)

W. B. Cowan, M. L. Rowell, “Phosphor constancy in color video monitors,” Color Res. Appl. 11, 34–38 (1986).

Invest. Ophthalmol. Vis. Sci. (5)

J.-M. Gorrand, F. C. Delori, “A method for assessing the photoreceptor directionality,” Invest. Ophthalmol. Vis. Sci. 31/4, 425 (1990); S. A. Burns, A. E. Elsner, J. M. Gorrand, M. R. Kreitz, “Variability in color matching, photoreceptor alignment, and the Stiles–Crawford II effect,” in 1991 Annual Meeting, Vol. 17 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), p. 24.

R. W. Knighton, S. G. Jacobson, C. M. Kemp, “The spectral reflectance of the nerve fiber layer of the macaque retina,” Invest. Ophthalmol. Vis. Sci. 30, 2393–2402 (1989).

M. Alpern, D. H. Krantz, “Visual pigment kinetics in abnormalities of the uvea–retinal epithelium interface in man,” Invest. Ophthalmol. Vis. Sci. 20, 183–203 (1981).
[PubMed]

G. J. van Meel, D. van Norren, “Foveal densitometry in retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 24, 1123–1130 (1983).
[PubMed]

A. E. Elsner, S. A. Burns, M. R. Kreitz, R. H. Webb, “Sensitivity maps vs. cone pigment density distribution,” Invest. Ophthalmol. Vis. Sci. 31/4, 108. (1990).

Invest. Ophthalmol. Vis. Sci. Suppl. (1)

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment concentration in normal and photocoagulated retina.” Invest. Ophthalmol. Vis. Sci. Suppl. 30, 370. (1989).

J. Opt. Soc. Am. A (1)

S. A. Burns, A. E. Elsner, “Color matching at high illuminances: the color match area effect and photopigment bleaching,” J. Opt. Soc. Am. A 2, 916–920 (1985).
[CrossRef]

Ophthal. Physiol. Opt. (2)

J.-M. Gorrand, “Reflection characteristics of the human fovea assessed by reflecto-modulometry,” Ophthal. Physiol. Opt. 9, 53–60 (1989).
[CrossRef]

J.-M. Gorrand, F. Bacin, “Use of reflecto-modulometry to study the optical quality of the inner retina,” Ophthal. Physiol. Opt. 9, 198–204 (1989).
[CrossRef]

Opt. Eng. (1)

P. Artal, J. Santamaria, J. Bescos, “Optical-digital procedure for the determination of white-light retinal images of a point test,” Opt. Eng. 28, 687–690 (1989).

Trans. Ophthalmol. Soc. UK (1)

C. M. Kemp, D. J. Faulkner, S. G. Jacobson, “Visual pigment levels in retinitis pigmentosa,” Trans. Ophthalmol. Soc. UK 103, 453–456 (1983).

Vision Res. (11)

P. E. Kilbride, J. S. Read, G. A. Fishman, M. Fishman, “Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea,” Vision Res. 23, 1341–1350 (1983).
[CrossRef] [PubMed]

V. C. Smith, J. Pokorny, D. van Norren, “Densitometric measurement of human cone photopigment kinetics,” Vision Res. 23, 517–524 (1983).
[CrossRef] [PubMed]

H. Ripps, R. A. Weale, “Cone pigments in the normal human fovea,” Vision Res. 3, 531–543 (1963); “Photo-labile changes and the directional sensitivity of the human fovea,” J. Physiol. 173, 57–64 (1964); “Analysis of foveal densitometry,” Nature (London) 205, 52–56 (1965).
[CrossRef] [PubMed]

W. A. H. Rushton, G. H. Henry, “Bleaching and regeneration of cone pigments in man,” Vision Res. 8, 617–631 (1968).
[CrossRef] [PubMed]

M. Alpern, F. Maaseidvaag, N. Ohba, “The kinetics of cone visual pigments in man,” Vision Res. 11, 539–549 (1971).
[CrossRef] [PubMed]

D. van Norren, L. F. Tiemeijer, “Spectral reflectance of the human eye,” Vision Res. 26, 313–320 (1986).
[CrossRef] [PubMed]

G. J. van Blokland, “Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo,” Vision Res. 26, 495–500 (1986).
[CrossRef] [PubMed]

D. van Norren, J. van de Kraats, “Retinal densitometer with the size of a fundus camera,” Vision Res. 29, 369–374 (1989).
[CrossRef] [PubMed]

A. B. Fulton, R. M. Hansen, “The relationship of retinal sensitivity and rhodopsin in human infants,” Vision Res. 27, 697–704 (1987).
[CrossRef] [PubMed]

D. J. Faulkner, C. M. Kemp, “Human rhodopsin measurement using a T.V.-based imaging fundus reflectometer,” Vision Res. 24, 221–231 (1984).
[CrossRef] [PubMed]

D. van Norren, J. van der Kraats, “A continuously recording retinal densitometer,” Vision Res. 21, 897–905 (1981).
[CrossRef] [PubMed]

Visual Neurosci. (1)

H. D. Baker, R. Henderson, L. P. O’Keefe, “An improved retinal densitometer: design concepts and experimental applications,” Visual Neurosci. 3, 71–80 (1989). Although this paper uses 590 nm, there is also an infrared reference standard.
[CrossRef]

Other (19)

R. W. Knighton, S. G. Jacobson, M. I. Roman, “Specular reflection from the surface of the retina,” in Laser Surgery: Advanced Characterization, Theraputics, and Systems, K. Atsumi, N. R. Goldblatt, S. N. Joffe, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1066, 10–17 (1989).

I. Fram, J. S. Read, B. H. McCormick, G. A. Fishman, “In vivo study of the photolabile visual pigment utilizing the television ophthalmoscope image processor,” in Computers in Ophthalmology, R. H. Greenfield, A. Colenbrander (Institute of Electrical and Electronics Engineers, New York, 1979), pp. 133–144.

A. E. Elsner, S. A. Burns, G. W. Hughes, R. H. Webb, “Evaluating the photoreceptor/RPE complex with and SLO,” in Noninvasive Assessment of the Visual System, Vol. 3 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), pp. 40–43.

A. E. Elsner, R. Schwarz, S. A. Burns, M. R. Kreitz, “Retinal light scattering,” in 1990 Annual Meeting; Vol. 15 of 1990 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1990), paper MD5.

A. E. Elsner, S. A. Burns, M. R. Kreitz, J. J. Weiter, “New views of the retina/RPE complex: quantifying sub-retinal pathology,” in Noninvasive Assessment of the Visual System Vol. 1 of 1991 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1991), pp. 150–153.

A. E. Elsner, A. H. Jalkh, J. J. Weiter, “New devices for retinal imaging and function evaluation,” in Practical Atlas of Retinal Disease and Therapy, W. Freeman, ed. (Raven, New York, to be published).

J. E. Nasemann, R. O. W. Burk, eds., Laser Scanning Ophthalmoscopy and Tomography (Quintesenz-Verlag, Berlin, 1990).

J. E. E. Keunan, “Densitometry in diseases and senescence of the human retina,” dissertation (State University of Utrecht, Utrecht, 1988) is an anthology of published articles and work in progress at the time. It is available from the author.

A. E. Elsner, ed., Laser Sanning Ophthalmoscopy, Tomography, and Microscopy (Plenum, New York, to be published).

A. E. Elsner, S. A. Burns, F. C. Delori, R. H. Webb, “Quantitative reflectometry with the SLO,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz-Verlag, Berlin, 1990), pp. 109–121.

A. E. Elsner, S. A. Burns, R. H. Webb, “Photopigment densitometry with a scanning laser ophthalmoscope,” in 1988 Annual Meeting, Vol. II of 1988 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1988), paper WY3. These first results (also Ref. 5) were for rod and cone photopigments and different instrumentation and technique.

D. van Norren, “Towards improved instrumentation for retinal densitometry,” in Research in Retinitis Pigmentosa, E. Zrenner, H. Krastel, H.-H. Boebel, eds. (Pergamon, Oxford, 1987), Vol. 62, pp. 177–178; D. van Norren, J. van de Kraats, “Imaging retinal densitometry with a confocal scanning laser ophthalmoscope,” Vision Res. 29, 1825–1830 (1989).
[CrossRef] [PubMed]

G. Wyszecki, W. S. Stiles, Color Science (Wiley, New York, 1982).

A. Plesch, U. Klingbeil, “Optical characteristics of a scanning laser ophthalmoscope,” in New Methods in Microscopy and Low Light Imaging, J. E. Wampler, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1161, 390–398 (1989).

A. Plesch, U. Klingbeil, W. Rappl, C. Schroedel, “Scanning ophthalmic imaging,” in Laser Scanning Ophthalmoscopy and Tomography, J. E. Nasemann, R. O. W. Burk, eds. (Quintessenz, Munich, Germany, 1990), pp. 109–121.

A. E. Elsner, G. T. Timberlake, S. A. Burns, M. R. Kreitz, “High illuminance perimetry: Photopigment Mechanisms,” in Noninvasive Assessment of the Visual System, Vol. 7 of 1989 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1989), pp. 15–18.

F. J. van de Velde, A. E. Jalkh, A. E. Elsner, “Microperimetry with the scanning laser ophthalmoscope,” in Perimetry Update, 1990/1991, R. P. Mills, A. Heijl, eds. (Kugler, Amsterdam, 1991), pp. 93–101; J.-F. Chen, P. L. Lou, A. E. Elsner, R. M. Hansen, H.-M. Cheng, A. B. Fulton, “The effect of refractive error on retinal responses,” Invest. Ophthalmol. Vis. Sci. 32, 929 (1991).

AEM-40 modulators with modified E40ER drivers, IntraAction Corporation, Bellwood, Ill. The AOM must be oriented horizontally, since the Fourier transform of the modulation pulse contains frequencies other than the carrier frequency and thus deflects the beam a little. The horizontal orientation assures that the deflection is equal in the scan direction.

EG&G, RCA C30950E, Spec. 710 (Vaudreuil, Quebec, Canada).

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Figures (11)

Fig. 1
Fig. 1

Schematic diagram of the SLO that is used in these experiments. Light from five lasers is combined by dichroic mirrors: a 633-nm He–Ne laser, a 830-nm diode laser, a 594-nm He–Ne laser, a 543-nm He–Ne laser, and a multiline (514, 488, … nm) Ar-ion laser. Neutral density wedges and filters control the irradiance. AOM’s provide graphics and blanking of the retrace lines independently for all four visible wavelength lasers. The combined light passes through the circular port of the beam separator of the Rodenstock optical head. The Eye Research Institute custom-built electronics include circuits for motor control of the Rodenstock scanning and focus compensation system, cooling of the avalanche photodiode detector (APD), and the generation of video synchronization. They also amplify and condition the video signal for data collection.

Fig. 2
Fig. 2

SLO video system. The APD output signal is placed on a pedestal (A) and combined with the composite synch (B) to produce a composite video (C). The maximum system gain at a 600-nm incident light wavelength is ~ 200 mV/nW at C. The gain is controlled over a useful range of 10:1 by varying the APD bias voltage. See Subsection II.A.2.a for a discussion of composite synch generation. To stabilize the gain of the APD, its case is held at 10°C (50°F) by a thermoelectric cooler.

Fig. 3
Fig. 3

Composite video output from the SLO during part of a horizontal scan line that is approximately in the middle of the raster. The target was made by putting a thin, vertical strip of white paper across a hole cut in matte gray paper (Ce oxide). The beam scan begins on gray (c), then encounters black (b) (the hole), white (a), and again black (b), and finishes on gray (c). The light level is adjusted so that there is saturation of the video signal at the white stripes. The detector bias voltage is set as in a retinal densitometry experiment. Data were collected with a logic analyzer (HP 1631D) using 50-ns samples. The signal is 0 V during the horizontal blanking interval B, except when it is interrupted by the negative horizontal synch pulse S. An adjustment raises the base line b to a pedestal level P of ~ 5% of the saturation.

Fig. 4
Fig. 4

Schematic diagram of the model eye. A sapphire lens (of 24.5-mm focal length) is centered in a 12-mm circular hole with an adjustable iris diaphragm. A selected retina is placed in a slide holder, which is adjustable in distance from the lens with a Vernier scale.

Fig. 5
Fig. 5

Schematic view of the apertures and imaging modes (see Ref. 5). The lateral spread of light scattered from the structures of the retina, choroid, and sclera is sampled differently by different apertures. The structures from the anterior segment and vitreous are not shown, but these layers above the retina would be blocked or passed by the selection of the aperture analogously to the retinal, choroidal, and scleral layers. (Top row) Imaging without an aperture. The light that is scattered from many layers of the ocular fundus may reach the detector. (Second row) Small confocal aperture. Only light from nearby structures and layers can pass through the aperture to reach the detector. (Third row) large confocal aperture. Light that is more widely scattered or from deeper layers may return to the detector. (Bottom row) indirect mode aperture with a circular stop blocking light from nearby structures and superficial layers of the retina. Only more widely scattered light or light from deeper layers can pass through the aperture.

Fig. 6
Fig. 6

Comparison of open confocal and indirect imaging in 594-nm light for a 26-yr-old male observer. (Top row) dark-adapted images; (center row) bleached images; (bottom row) distribution of cone photopigment density difference, which is obtained as a density difference from the dark-adapted and bleached images in the top and middle panels. Whiter indicates higher density difference; blacker indicates lower density difference. Left column, open confocal mode data; right column, indirect mode data. The photographic prints cannot reproduce the dynamic range and contrast in the images. The density difference in the lower left panel is shown in pseudo-color in Ref. 1.

Fig. 7
Fig. 7

Comparison of open confocal and indirect mode imaging in 594-nm light for a 55-yr-old male observer. The data are displayed as in Fig. 6. The large spot is the fovea; the smaller one is a floater, which moved during testing. The density difference in the lower left-hand panel is shown in pseudo-color in Ref. 1 along with the top and middle panels at the left.

Fig. 8
Fig. 8

Images that are used in obtaining a photopigment density difference. They are acquired at 594 nm for a 21-yr-old male observer. (a) comparison of dark-adapted images (left) that were acquired with 594-nm light at 5.2 log Td with indirect mode imaging. (b) a bleached fundus image that is acquired in the same way. (c) distribution of the photopigment density difference that is obtained as a density difference from the dark-adapted and bleached images in the top panels. Lighter indicates high density; black indicates a density of zero. (Bottom right) control calculation of the density difference between two light-adapted images. This image more adequately represents the lack of density difference at peripheral locations and also the low contrast at the fovea in bleached images.

Fig. 9
Fig. 9

Images that are used in obtaining the photopigment density difference for a 50-yr-old female observer. They are unusual in that the choroidal vessels are seen, yet a density difference is obtained. The data are displayed as in Fig. 8.

Fig. 10
Fig. 10

Cone photopigment density distribution in the central 15 deg for the seven male observers in order of increasing age in years: top row, left (21) and right (25); second row, left (26) and right (39), third row, left (40) and right (50); fourth row, left (55) and right the density scale. All data were collected in indirect mode with the large field size. Lighter indicates a higher density difference; darker indicates a lower density difference.

Fig. 11
Fig. 11

Contour plot of cone photopigment density distribution for subject 1 superimposed on a smooth gray scale image. Density increments are 0.05. The highest density difference enclosed within a contour is 0.25, although the peak density is higher within this region.

Tables (1)

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Table I Potential Problems with Reflectometry

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