PubMed · 5972889
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P K Leppmann, B A Wieland. 1966. Visual distortion with two-colored spectacles.. https://doi.org/10.2466/pms.1966.23.3f.1043
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Light-adapted and dark-adapted electroretinograms were obtained in 27 premature infants who were screened for retinopathy of prematurity shortly after birth. Thirteen showed no retinopathy and 13 had mild to moderate retinopathy, which ranged from stage I, zone III (International Classification) to stage III, zone II. Measurements were made during the first 16 months of life. The configuration of the waveforms under both photopic and scotopic conditions changed during this period showing increased amplitudes of both the a- and the b-waves. A scotopic intensity series was performed and the b-wave amplitudes and implicit times were measured. The b-wave amplitude data were averaged for three adult control subjects, for infants without retinopathy of prematurity measured at 3-4 and at 6-7 months and for infants with retinopathy of prematurity measured at 3-4 and at 6-7 months. The Naka-Rushton function was fitted to the average data. The Rmax increased from 3 to 6 months and from 6 months to adulthood, and the Isat values decreased over this age range. The b-wave implicit times were within normal range in the 6-month data. There was no difference in Rmax or Isat for infants with and without ROP.
New possible causes and unexplored aspects of the electroretinogram were evaluated in a case of vitamin A deficiency secondary to surgical therapy for morbid obesity. The Naka-Rushton equation, applied to the scotopic b-wave, demonstrated the quantal catch reduction caused by the loss of rhodopsin in the outer segment of photoreceptors. Study of the Fourier analysis of the photopic 20-Hz response suggested a primary involvement of the external retinal layers, with an indirect alteration of the inner layer. The electroretinogram oscillatory potentials showed alterations explained by the involvement of their generators related to the primary photoreceptor lesion.
We recorded electroretinograms from anesthetized cynomolgus monkeys for 30 monochromatic (400-700 nm) full-field stimuli with five different stimulation levels presented without a background light. Waveforms were analyzed by means of principal component analysis to investigate the influence of stimulus intensity on long- and middle-wavelength cone interaction. With increasing levels of stimulus intensity, the middle-wavelength cone system showed a slight peak shift and a noticeable increase in response, while the long-wavelength cone system showed an obvious change in peak wavelength rather than response. In addition, spectral responses in the long-wavelength cone system increased over the red region, whereas they decreased over the yellow region. On the other hand, responses in the middle wavelength cone system increased over the yellow region much more than over the green region. These complicated changes are thought to indicate the induction of long- and middle-wavelength cone interaction by stimulus light.