Cone Optical Density and Bleaching

We have developed new psychophysical approaches to measuring the regeneration kinetics of the human eye and done basic research into factors affecting these measurements.  In addition we have used this technique to show that photopigment kinetics are altered in a number of retinal diseases, but only slightly in normal aging.

  1. Burns S A and Elsner AE, "Color matching at high illuminances: the color-match- area effect and photopigment bleaching". J. Opt. Soc. Amer. A 2, 698-704, 1985. (full text)
  2. Burns SA, Elsner AE, Lobes LA Jr., and Doft BH "A Psychophysical technique for measuring cone photopigment bleaching". Invest. Ophthalmol. and Vis. Sci. 28,711-717, 1987.
  3. Elsner AE, Burns SA, Lobes LA Jr., and Doft BH "Photopigment bleaching abnormalities in diabetes". Invest. Ophthalmol. and Vis. Sci. 28, 718-723, 1987.
  4. Elsner AE, Burns SA, and Lobes LA Jr. "Foveal Cone Pigment Optical Density in Retinitis Pigmentosa". Appl. Optics. 26,1378-1384, 1987. (full text)
  5. Burns SA, Elsner AE, and Lobes LA "Photopigment Bleaching in Central Serous Retinopathy". Applied Optics. 27, 1045-1049, 1988. (full text)
  6. Elsner AE, Berk L, Burns SA, and Rosenberg PR. "Aging and human cone photopigments", J. Opt. Soc. Amer. A. 5, 2106-2112, 1988.  (full text)
  7. Elsner, AE, and Burns, SA and Webb RH "Mapping Cone Pigment Optical Density in Humans" J. Opt. Soc. Amer. 10, 52-58, 1993. (full text)
  8. Burns SA, and Elsner AE, " Color-matching at high illuminances: photopigment optical density and pupil entry" J. Opt. Soc. Amer. 10, 221-230, 1993.

  9. Elsner, AE, Burns, SA, Beausencourt, E, and Weiter, JJ, "Foveal cone photopigment distribution: small alterations associated with macular pigment distributions", Invest. Ophthalmol. Vis. Sci. 39,2394-2404, 1998

  10. Elsner, AE, Burns, SA, and Weiter JJ, "Cone Photopigment in Older Subjects: Decreased Optical Density in Early Age-Related Macular Degeneration". J. Opt. Soc. Amer A 19: 215-222, 2002-(full text)

  11. Prieto, P, McLellan, J.S., and Burns, S.A. Investigating The Light Absorption In A Single Pass Through The Photoreceptor Layer By Means Of The Lipofuscin Fluorescence. Vision Research 45 (15): 1957-1965, 2005(full text)

Bleaching of the Cone Photopigments Does not Follow First Order Kinetics

BLEACH.GIF (6462 bytes)

This is a note to indicate that while first order kinetics are convenient to use when modeling the photopigments they have been shown to deviate from the data obtained from both psychophysical and densitometric measurements. Burns and Elsner (1989) compare results using retinal densitometry to result obtained psychophysically to show that both techniques demonstrate the same departures from first order kinetics. The graph below shows measurements obtained using a color matching technique. Data obtained using an ascending series of retinal illuminances (allowing full adaptation between settings) are considerable steeper than the first order predictions (curve labeled ascending). We then examined data for a descending series of retinal illuminances (which is in some ways similar to the densitometry where measurements are often made after an initial "clearing" bleach). Here the data are shallower, but still steeper than the first order predictions.