June 2015
Volume 56, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2015
Densitometry of Cone Photoreceptors in Human Eyes by Adaptive Optics Scanning Laser Ophthalmoscopy
Author Affiliations & Notes
  • Masakazu Hirota
    Applied Visual Science, Osaka University, Suita-shi, Japan
  • Suguru Miyagawa
    Applied Visual Science, Osaka University, Suita-shi, Japan
    Fundamental Technology Sec, R&D Department, Topcon, Itabashi, Japan
  • Hiroyuki Kanda
    Applied Visual Science, Osaka University, Suita-shi, Japan
  • Takao Endo
    Ophthalmology, Osaka University, Suita-shi, Japan
  • Tibor Karl Lohmann
    Applied Visual Science, Osaka University, Suita-shi, Japan
    Ophthalmology, RWTH Aachen University, Aachen, Germany
  • Takeshi Morimoto
    Applied Visual Science, Osaka University, Suita-shi, Japan
  • Takashi Fujikado
    Applied Visual Science, Osaka University, Suita-shi, Japan
  • Footnotes
    Commercial Relationships Masakazu Hirota, None; Suguru Miyagawa, Topcon (E); Hiroyuki Kanda, None; Takao Endo, None; Tibor Lohmann, None; Takeshi Morimoto, None; Takashi Fujikado, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2015, Vol.56, 4942. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Masakazu Hirota, Suguru Miyagawa, Hiroyuki Kanda, Takao Endo, Tibor Karl Lohmann, Takeshi Morimoto, Takashi Fujikado; Densitometry of Cone Photoreceptors in Human Eyes by Adaptive Optics Scanning Laser Ophthalmoscopy . Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):4942.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: To measure the changes in the reflectance of human cone photoreceptors in situ with an adaptive optics scanning laser ophthalmoscope (AO-SLO) before and after bleaching.

Methods: Eight eyes of 8 healthy young adult subjects (age: 21-33 years) were studied. The changes in the cone reflectance were measured with a custom-built AO-SLO (developed by Osaka University and Topcon) with a sampling rate of 5-Hz. The AO-SLO had a resolution of 512 × 512 pixels and had a 12-bit gray scale resolution. The field of view was set at 7×7 degrees with the center at 1 or 3 degrees temporal to the fovea. We calculated the cone density in this area. For bleaching, we used 630-nm red light emitting diodes (LEDs, brightness of 3600 cd/m2). Twenty-one red LEDs were set in a circular pattern and placed 7 cm in front of the cornea of the right eye. After mydriasis and 10 min of dark-adaptation, images of the cone mosaics were recorded continuously for 300 seconds without light stimulation, then after bleaching by the LEDs for 300 seconds, and then for 300 seconds after the cessation of light stimulation. The measurements were made in a dark room of 0.01 lx. The average cone reflectance was computed by the ImageJ software (Rasband W, NIH, USA), and the average cone reflectance before light stimulation was set as the baseline. The reflectance at the baseline was compared to that during and after light stimulation at 1 and 3 degrees.

Results: The average cone density was significantly higher at 51283.87±2736.97 cells/mm2 at 1 degree than the 30388.38±2176.05 cells/mm2 at 3 degrees (P<0.001 Wilcoxon). After light-adaptation, the reflectance increased relative to that at the baseline by 134.3±13.8% at 1 degree and by 126.0±10.2% at 3 degrees (P<0.001, Wilcoxon). The increase in the cone reflectance after bleaching at 1 degree was significantly greater than that at 3 degrees (P<0.05, Wilcoxon).

Conclusions: The significantly greater reflectance change where the cone density was higher (1 degree) indicates that the amount of reflectance change is related to the cone density.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×