Electroretinograms in Carriers of Blue Cone Monochromatism

doi:10.1016/0002-9394(86)90154-6

American Journal of Ophthalmology

Volume 102, Issue 2, August 1986, Pages 254-261

https://doi.org/10.1016/0002-9394(86)90154-6 Get rights and content

We recorded full-field electroretinograms from seven female obligate carriers of X-linked blue cone monochromatism and eight daughters of obligate carriers. We observed that all obligate carriers had one or more of the following abnormalities: delayed cone b-wave implicit times to 30-Hz white flicker, loss of the a₁ oscillation in responses to single flashes of white light under dark-adapted conditions, subnormal b-wave amplitudes to single flashes of white light under dark-adapted conditions, and subnormal cone responses to 30-Hz white flicker. All had normal rod responses to blue light. Three of eight daughters of obligate carriers had abnormal electroretinograms comparable to those recorded from obligate carriers. These obligate carriers have a partial but comparable deficiency of red and green cone function.

References (19)

H.R. Blackwell et al.
Visual function of “typical” and “atypical” congenital achromatopsia, abstract
Vision Res.
(1961)
G. Verriest
Les courbes spectrales photopiques d'efficacitélumineuse dans les déficiences congénitales de la vision des couleurs
Vision Res.
(1971)
E.L. Berson et al.
Color plates to help identify patients with blue cone monochromatism
Am. J. Ophthalmol.
(1983)
E.L. Berson et al.
Electroretinographic testing as an aid in detection of carriers of X-chromosome-linked retinitis pigmentosa
Am. J. Ophthalmol.
(1979)
H.R. Blackwell et al.
Blue mono-cone monochromacy. A new color vision defect
J. Opt. Soc. Am.
(1957)
H.R. Blackwell et al.
Blue mono-cone monochromacy. Comparison with rod monochromacy
J. Opt. Soc. Am.
(1959)
H.R. Blackwell et al.
Rod and cone receptor mechanisms in typical and atypical congenital achromatopsia
Vision Res.
(1965)
M. Alpern et al.
π₁ cone monochromatism
Arch. Ophthalmol.
(1965)
M. Alpern et al.
Color vision in blue cone monochromacy
J. Physiol.
(1971)

There are more references available in the full text version of this article.

Cited by (27)

Blue cone monochromacy and gene therapy
2023, Vision Research
Blue cone monochromacy (BCM) is a congenital vision disorder characterized by complete loss or severely reduced long- and middle-wavelength cone function, caused by mutations in the OPN1LW/OPN1MW gene cluster on the X-chromosome. BCM patients typically suffer from poor visual acuity, severely impaired color discrimination, myopia, and nystagmus. In this review, we cover the genetic causes of BCM, clinical features of BCM patients, genetic testing, and clinical outcome measurements for future BCM clinical trials. However, our emphasis is on detailing the animal models for BCM and gene therapy using adeno-associated vectors (AAV). We describe two mouse models resembling the two most common causes of BCM, current progress in proof-of-concept studies to treat BCM with deletion mutations, the challenges we face, and future directions.
Deletion of the X-linked opsin gene array locus control region (LCR) results in disruption of the cone mosaic
2010, Vision Research
Blue cone monochromacy (BCM) is an X-linked condition in which long- (L) and middle- (M) wavelength-sensitive cone function is absent. Due to the X-linked nature of the condition, female carriers are spared from a full manifestation of the associated defects but can show visual symptoms, including abnormal cone electroretinograms. Here we imaged the cone mosaic in four females carrying an L/M array with deletion of the locus control region, resulting in an absence of L/M opsin gene expression (effectively acting as a cone opsin knockout). On average, they had cone mosaics with reduced density and disrupted organization compared to normal trichromats. This suggests that the absence of opsin in a subset of cones results in their early degeneration, with X-inactivation the likely mechanism underlying phenotypic variability in BCM carriers.
Mammalian Photopigments
2008, The Senses: A Comprehensive Reference
Mammalian photopigments are typically located within the lipid membranes of rod and cone photoreceptors. They absorb incident light and, through a complex phototransduction cascade, relay information to downstream visual neurons. Recent results emerging from a variety of experimental approaches have greatly enhanced our understanding of photopigment structure and function. This chapter examines the diverse family of mammalian photopigments, considering their structure, function, and evolution, as well as their role in color vision and human retinal disease.
Factor structure and ammonia-related modulation of the human retinal oscillatory potentials
2001, Clinical Neurophysiology
Objective: To investigate in man the factor structure of retinal oscillatory potentials (OPs) to full-field luminance stimulation (0.9–9.5 cd.s.m⁻²) and the correlation with the spontaneous fluctuations of plasma ammonia.
Methods: Six male healthy volunteers were studied. Five OP recordings and ammonia determinations (GLDH method) were obtained for each subject at 2 h interval during an 8 h experimental session. A standard factor analysis was applied on the OP latency (time from stimulus to peak) and amplitudes values.
Results: Two consecutive factors on latencies and two factors on amplitudes were identified, consistent with reported differences between the earlier and later OP waves. The model explained a large portion of the OP variance. Both factors on latencies and factor 1 on amplitudes were directly correlated to the stimulus intensity and the ammonia plasma concentration in the 15.8–39.5 μmol/l range. Factors 1 and 2 on latencies decreased and factor 1 on amplitude increased at increasing stimulus intensities. The latency factors decreased and the amplitude factor increased with increasing ammonia concentration. Factor 2 on amplitudes did not correlate with the stimulus intensity or ammonia concentration.
Conclusions: The factor structure further supports the evidence of functional differences between early and late OP waves. The observed correlation conceivably reflects a role of ammonia in the modulation of retinal electrophysiology in physiological conditions and potentially accounts for spontaneous variability in otherwise controlled electrophysiological studies.
Clinical and electroretinographic findings of female carriers and affected males in a progressive X-linked cone-rod dystrophy (COD-1) pedigree
2000, Ophthalmology
To study the clinical and electroretinographic findings of affected males and female carriers in a family with X-linked cone–rod dystrophy (COD-1).
Observational case series.
Twenty-five members of a five-generation pedigree were examined.
A history of visual impairment including age at onset, loss of acuity, color vision abnormalities, photophobia, and nyctalopia was obtained. A complete ophthalmologic examination was performed, including kinetic perimetry with a Goldmann perimeter, FM 100-hue testing, and standardized Ganzfeld electroretinography following the ISCEV protocol.
Patients were classified as affected or unaffected on the basis of the clinical examination. All carrier females had affected sons.
Nine affected males and seven female carriers were identified. Affected males noted decreased visual acuity and poor color vision within the first two decades of life. Early in the disease, macular retinal pigment epithelial (RPE) changes were found that progressed to an atrophic macular scar by the fifth decade. Evidence of progression from macular pigment mottling to an atrophic macular lesion over a 13-year period was identified in one patient. The photopic, single-flash, b-wave amplitude was low in all affected males and declined with age. The 30-Hz flicker b-wave implicit times were abnormally prolonged in all affected males. Female carriers were asymptomatic although three had slightly abnormal color vision and small paracentral field defects and subtle RPE defects were found in three carriers. Carriers demonstrated prolongation of the 30-Hz flicker b-wave implicit time and interocular asymmetry. Five of seven carriers and two affected males demonstrated reduced oscillatory potentials and an abnormal-appearing flattened photopic a-wave. Five men and two women demonstrated a characteristic tapetal-like retinal sheen.
Affected patients in this pedigree demonstrate early loss of visual acuity and poor cone function with late rod involvement. Female carriers may appear clinically normal or may be identified by subtle color vision defects, fundus abnormalities, prolongation of the 30-Hz flicker implicit time with interocular asymmetry, or an abnormal flattened photopic a-wave. Genetic linkage analysis of this family was recently reported and the disease-causing gene has been mapped to an approximately 1-Mb interval on chromosome Xp11.4.
Recommended standards for electroretinograms and visual evoked potentials. Report of an IFCN committee
1993, Electroencephalography and Clinical Neurophysiology

View all citing articles on Scopus

This study was supported by National Eye Institute Project Grant EY00169 (Drs. Berson and Sandberg), by the National Retinitis Pigmentosa Foundation (Drs. Berson and Sandberg), and by the Maine Sight Conservation, Inc., and the Lions Clubs of Maine (Drs. Bromley and Roderick).

Reprint requests to Eliot 1. Berson, M.D., BermanGund Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA 02114.

View full text

Electroretinograms in Carriers of Blue Cone Monochromatism

Vision Res.

Vision Res.

Am. J. Ophthalmol.

Am. J. Ophthalmol.

Blue mono-cone monochromacy. A new color vision defect

J. Opt. Soc. Am.

Blue mono-cone monochromacy. Comparison with rod monochromacy

J. Opt. Soc. Am.

Rod and cone receptor mechanisms in typical and atypical congenital achromatopsia

Vision Res.

π1 cone monochromatism

Arch. Ophthalmol.

Color vision in blue cone monochromacy

J. Physiol.

π₁ cone monochromatism