December 2002
Volume 43, Issue 13
ARVO Annual Meeting Abstract  |   December 2002
S-Cone ERG in Cocaine-Dependent Humans and Controls
Author Affiliations & Notes
  • JM Harrison
    Dept of Ophth
    Univ of Texas Hlth Sci Ctr San Antonio TX
  • HA Reitsamer
    Dept of Physiology Univ of Vienna Medical School Vienna Austria
  • MM Alvarado-Garcia
    Dept of Ophth
    Univ of Texas Hlth Sci Ctr San Antonio TX
  • JD Roache
    Dept of Psychiatry
    Univ of Texas Hlth Sci Ctr San Antonio TX
  • A Elkashef
    Div of Treat Res and Development NIH/NIDA Bethesda MD
  • J Mojsiak
    Div of Treat Res and Development NIH/NIDA Bethesda MD
  • Footnotes
    Commercial Relationships   J.M. Harrison, None; H.A. Reitsamer, None; M.M. Alvarado-Garcia, None; J.D. Roache, None; A. Elkashef, None; J. Mojsiak, None. Grant Identification: Support: N01 DA-9-8101, FWF1866-MED
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 1193. doi:
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      JM Harrison, HA Reitsamer, MM Alvarado-Garcia, JD Roache, A Elkashef, J Mojsiak; S-Cone ERG in Cocaine-Dependent Humans and Controls . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1193.

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

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Abstract: : Purpose: To determine whether the short wavelength sensitive cone (S-cone) ERG of cocaine-dependent humans is different from that of controls. A previous study showed that S-cone b-wave amplitudes were reduced in cocaine-dependent humans,1 but this finding has not been independently replicated. Method: As part of a larger therapeutic study, we recorded ganzfeld S-cone ERGs from 14 cocaine-dependent subjects (DSM-IV criteria) using cocaine (urinalysis) and 10 age-matched controls. The S-cone ERG isolation by adaptation to a bright yellow ganzfeld is similar to a previously described method.2 The ERGs were produced by 5 flashes/s superimposed on a 6449 td background produced by 15 diffused yellow LEDs (595 nm, 5077 td) and 12 green LEDs (535 nm, 1372 td) presented in a custom ganzfeld (0.2 m diameter). ERGs were produced by "blue", "green", and "red" flashes (Wratten 98, 61, and 29 filters, respectively). Dilated pupil diameter was 8 mm. ERGs were recorded by Burian-Allen-Lawwill electrodes. Results: The S-cone ERG configuration produced by the "blue" flash consisted of a small a-wave (1.3 µV 13 ms), an early b-wave (2 µV, 23 ms), a negative trough (1 µV, 31 ms) a later S-cone b-wave (4 µV, 44 ms), and a large, late negative wave (7 µV, 83 ms) . The ERG produced by the "green" and "red" flashes, whose brightnesses were adjusted to produce approximately the same early b-wave amplitude, lacked the later b-wave and negative wave. No ERG component amplitudes differed significantly in the cocaine-dependent subjects compared to those of controls. Only the peak time of the negative trough (peak time 31 ms) produced by the "red" flash differed significantly (p=0.001) in the two groups. Conclusion: The mean S-cone b-wave amplitude of 20 cocaine-dependent subjects in the earlier study was 48% less than that of 20 controls.1 Our data do not indicate a large mean difference in S-cone b-wave amplitude in the two groups. The power was 0.8 to detect a 40% difference with p<0.05. Two cocaine-dependent subjects, however, lacked the late S-cone b-wave. In the cocaine-dependent population, there may be a subgroup with small or absent S-cone ERGs. The numbers of this subgroup may not be proportionately represented in our sample. 1) M. Roy, et al. Arch Gen Psychiatry 54:153-156, 1997. 2) S.E. Simonsen and T. Rosenberg Doc Ophthalmol 91:323-332, 1996.

Keywords: 390 drug toxicity/drug effects • 395 electroretinography: clinical • 514 pharmacology 

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