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PubMed2002

Visual changes secondary to initiation of amiodarone: a case report and review involving ocular management in cardiac polypharmacy.

BACKGROUND: Amiodarone is a benzofuran derivative used to treat cardiac arrhythmias. The most-common ocular symptom is colored rings around lights. Common ocular findings include comeal micro-deposits and lens opacities. An amiodarone optic neuropathy has been described. Digoxin is a cardiac glycoside used to treat cardiac arrhythmias and heart failure. It is known to cause dyschromatopsia, visual disturbances, and visual-field defects. Digoxin serum levels and toxicity risks increase with the addition of amiodarone. CASE REPORT: Soon after initiation of amiodarone HCl (200 mg/day), a 76-year-old man came to us with symptoms of visual "shining," glare, color vision anomalies, and gradually decreased vision. Best-corrected visual acuity was 20/50 O.D. and 20/60 O.S. Ishihara color plates showed a marked, acquired color vision defect O.D., O.S. Biomicroscopy revealed amiodarone corneal deposits. The optic nerve appeared healthy, with no visible swelling in each eye. Amiodarone was discontinued after discussion with the cardiologist. On followup, the patient reported disappearance of symptoms. Visual acuity had improved to 20/30(+2) O.D. and 20/30 O.S. Ishihara color plates showed normal color vision. CONCLUSIONS: As the elderly population and the incidence of heart disease increase in the United States, more people will probably be using heart drug therapy. Our case presents some of the challenges involved with managing ocular toxicity of these cardiac drugs. While both amiodarone and digoxin can cause permanent visual changes, the ocular effects are often reversible. Therefore, ocular examination at baseline and every 6 months is indicated for patients receiving a regimen of amiodarone and/or digoxin therapy.

Aged↗
PubMed1992

Japanese family with blue cone monochromatism.

The diagnosis of blue cone monochromatism (BCM) is based on severely affected color vision with preserved blue function, nearly nonrecordable photopic ERG, and a family pedigree compatible with X-linked inheritance. We have studied the color vision and ocular function of three members of a family with BCM and a female carrier in the same family. Two of the three affected family members, 9- and 7-year-old brothers, showed the unique features of BCM in their color vision and ERG. The third affected family member, a 43-year-old uncle, showed achromatic vision. He had diabetic retinopathy and moderate cataract which were thought to disturb his blue cone function, causing apparent rod monochromatism. The female carrier, the mother of the brothers, showed normal visual functions except for a slight reduction in photopic ERG amplitude. We believe that this is the first description of BCM in a Japanese family.

Adult↗
PubMed1992

Vision defects in albinism.

We have examined the possible presence of color vision anomalies in 9 individuals (17 eyes, 1 blind) with fundus findings suggesting ocular albinism using the Ishihara plates, the 28-hue Roth test, and the Davico anomaloscope. Results indicate that four of these individuals show no sign of the anomalies expected in an albino in either of the two eyes. Of the remaining cases, two are simple deuteranomals in both eyes, according to Pickford's classification criteria. The rest have protanomaly; however, in these the deviation toward red appears in both eyes in only one subject, whereas in the other two subjects it appears in only one eye, their binocular color vision being basically normal. Our study shows that a large proportion of these albinos have photophobia, pendular nystagmus, strabismus, noticeable refractive errors (astigmatism and high myopia), and poor visual acuity [usually less than 6/30 (20/100) with correction]. The measurement of contrast sensitivity function (CSF) indicates that the frequency of 12 cpd cannot be perceived, even in binocular vision.

Adolescent↗
PubMed1985

Improved color test results with large-field viewing in dichromats.

Standard methods for screening color vision defects may be expected to underestimate a color defective's complete chromatic discrimination abilities because the viewing field is confined to the fovea (central 2 degrees). Large-field (8 degrees) Farnsworth-Munsell 100-hue and dichotomous (D-15) tests were constructed. The 100-hue test, along with its small-field counterpart, was administered to five deuteranopes (green defectives) and four protanopes (red defectives). The D-15 small- and large-field tests were given to these same subjects with the addition of two deuteranopes and one protanope. Both deuteranopes and protanopes showed marked improvement on the large-field D-15 and 100-hue tests. This improvement in performance for large-field over small-field viewing is consistent with color-matching data, which show large-field trichromacy in observers who have been demonstrated to be small-field red-green dichromats. These results suggest that tests confined to central fovea viewing provide an incomplete functional description of the color vision of an appreciable number of classic dichromats.

Color Perception↗
PubMed1997

Clinical course of a cohort in the Cuban epidemic optic and peripheral neuropathy.

Nearly 51,000 Cubans were afflicted during an outbreak of an optic neuropathy (ON) and peripheral neuropathy (PN) between 1991 and 1993. We re-examined 14 of 20 affected individuals 16 months after an initial evaluation. The optic features were painless symmetric vision loss with poor visual acuity, color vision loss, central or cecocentral scotoma, optic disc pallor, and nerve fiber layer drop-out. The neurologic symptoms included stocking-glove sensory changes, hearing loss, leg cramps, sensory ataxia, hyperactive or absent reflexes, and complaints of memory loss. Two of 11 ON probands tested harbored Leber's hereditary optic neuropathy (LHON)-associated mitochondrial DNA mutations. All patients had received multivitamin therapy. We performed comparisons using the paired two-tailed t test. On re-examination, 12 of 14 patients demonstrated improvement. One patient remained unchanged. One woman with the nt-3460 mtDNA mutation showed a decline in vision. In patients not harboring mtDNA mutations, overall visual acuity, color vision, and peripheral neuropathy manifestations improved significantly (p < 0.001 for each manifestation). Most of the patients with Cuban ON and PN improved on multivitamin therapy. The significance of the mtDNA mutations is unclear. In the 2 LHON patients, manifestation of the disease may have been precipitated by nutritional deficiency. Patients with poor recovery or further deterioration should be evaluated for other factors, including poor vitamin therapy compliance and alternative diagnoses.

Adult↗
PubMed2000

Clinical and electroretinographic findings of female carriers and affected males in a progressive X-linked cone-rod dystrophy (COD-1) pedigree.

OBJECTIVE: To study the clinical and electroretinographic findings of affected males and female carriers in a family with X-linked cone-rod dystrophy (COD-1). DESIGN: Observational case series. PARTICIPANTS: Twenty-five members of a five-generation pedigree were examined. METHODS: 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. MAIN OUTCOME MEASURES: Patients were classified as affected or unaffected on the basis of the clinical examination. All carrier females had affected sons. RESULTS: 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. CONCLUSIONS: 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.

Adolescent↗
PubMed1992

Color defective drivers and safety.

At least seven million drivers in North American cannot reliably identify red and green lights. The common assumption by traffic authorities that no serious problems exist is contradicted by the data on color vision, the testimonies of color defective drivers, studies under controlled conditions, and by reliable accident statistics. Color defective drivers can be provided with the same measure of traffic light safety as for normals. Brake lights on vehicles can be made equally effective for color defectives. Suggestions are provided to help those with color defective vision to compensate for their problems.

Accidents, Traffic↗
PubMed2005

Diversity of mammalian photoreceptor properties: adaptations to habitat and lifestyle?

All mammalian retinae contain rod photoreceptors for low-light vision and cone photoreceptors for daylight and color vision. Most nonprimate mammals have dichromatic color vision based on two cone types with spectrally different visual pigments: a short-wavelength-sensitive (S-)cone and a long-wavelength-sensitive (L-)cone. Superimposed on this basic similarity, there are remarkable differences between species. This article reviews some striking examples. The density ratio of cones to rods ranges from 1:200 in the most nocturnal to 20:1 in a few diurnal species. In some species, the proportion of the spectral cone types and their distribution across the retina deviate from the pattern found in most mammals, including a complete absence of S-cones. Depending on species, the spectral sensitivity of the L-cone pigment may peak in the green, yellow, or orange, and that of the S-cone pigment in the blue, violet, or near-ultraviolet. While exclusive expression of one pigment per cone is the rule, some species feature coexpression of the L- and S-pigment in a significant proportion of their cones. It is widely assumed that all these variations represent adaptations to specific visual needs associated with particular habitats and lifestyles. However, in many cases we have not yet identified the adaptive value of a given photoreceptor arrangement. Comparative anatomy is a fruitful approach to explore the range of possible arrangements within the blueprint of the mammalian retina and to identify species with particularly interesting or puzzling patterns that deserve further scrutiny with physiological and behavioral assays.

Adaptation, Physiological↗
PubMed2000

Multifocal ERG in chloroquine retinopathy: regional variance of retinal dysfunction.

BACKGROUND: A study was carried out to evaluate the regional variance of retinal dysfunction in chloroquine retinopathy. METHODS: In three patients with different stages of chloroquine retinopathy, ophthalmologic evaluations including recording of full-field electroretinogram (ISCEV standard) and multifocal electroretinogram were performed. RESULTS: In one patient with mild chloroquine retinopathy the visual acuity, visual fields and full-field electroretinogram were normal, but retinal dysfunction was indicated by color vision disturbances. The second patient had moderate chloroquine retinopathy with normal visual acuity, visual fields and dark-adapted full-field electroretinogram; light-adapted and flicker full-field electroretinogram responses were, however, borderline and color vision was abnormal. The third patient had severe chloroquine retinopathy with reduced visual acuity, visual field and color vision defects, and a reduced full-field electroretinogram. In the multifocal electroretinogram, recorded with 61 hexagons, amplitudes and implicit times were evaluated in rings surrounding the center. In all three patients severe dysfunction (either amplitudes or implicit times) was found in the parafoveal and perifoveal areas. In the fovea and towards the periphery the function was normal or only moderately reduced. CONCLUSION: Chloroquine retinopathy of different severity presents with characteristic alterations in the multifocal electroretinogram. Regional distribution of cone dysfunction is in agreement with previously reported histologic findings. The multifocal electroretinogram can detect retinal dysfunction in chloroquine retinopathy even when the full-field electroretinogram is normal and retinal alterations are subtle.

Adaptation, Ocular↗
PubMed1978

Autosomal recessive incomplete achromatopsia with protan luminosity function.

A unique form of dichromatic color vision is described in a family with incomplete achromatopsia. In 1966, incomplete achromatopsia was diagnosed in 4 of 14 children of a consanguineous marriage. The 4 affected had best visual acuities of 6/60 or 6/180, pendular nystagmus, and aversion to bright lights. The ERG showed minimal photopic responses. No abnormality of rod function was present. There was a severe color vision defect. In 1976, one of the patients returned for further color testing. Color tests included measurement of the luminous efficiency function using heterochromatic flicker photometry and colorimetric evaluation. The luminous efficiency function resembled that of the protanope. From the colorimetric measurements, we conclude that the patient has a unique form of dichromatic color vision mediated by two visual photopigments: the normal MWS cone photopigment and a photopigment with the spectral characteristics of rhodopsin.

Adolescent↗
PubMedDate not supplied

Clinical heterogeneity between two Japanese siblings with congenital achromatopsia.

Congenital achromatopsia is a stationary retinal disorder with autosomal recessive inheritance. It is characterized by significant attenuation of cone-photoreceptor function. Symptoms include photophobia, nystagmus, and poor visual acuity from birth. Unlike in cone or cone-rod dystrophies, the retinal fundus usually appears normal. Here we describe two siblings with congenital achromatopsia, who exhibit different ophthalmic phenotypes. History was taken, and ophthalmic examinations were performed in a 7-year-old girl and her 5-year-old brother, who were referred to our department because of poor visual acuity. Two of their grandparents were brother and sister, suggesting an autosomal recessive transmission in inheritance. They have been followed for more than 13 years since the initial evaluation. Symptoms, visual acuity, and kinetic visual field were very similar to each other, consistent with findings of typical congenital achromatopsia. However, color-vision tests suggested that the brother had residual color discrimination, but the sister did not. The siblings had different full-field electroretinographic and spectral-sensitivity findings: residual cone functions were detected in only the brother, in agreement with his residual color vision. They also had different findings of retinal fundi and ocular refractions: the sister had bilaterally atrophic-appearing macular lesions and myopic errors. In contrast, the brother remains hyperopia and has exhibited no specific retinal findings until age 18 years. The causes why both complete and incomplete achromats occur in the siblings are uncertain but might be caused by modifying effects of sex-related genes or by environmental factors influencing certain gene regulations in cone photoreceptors.

Child↗
PubMed2004

Serious ophthalmic pathology compromising vision in HCV/HIV co-infected patients treated with peginterferon alpha-2b and ribavirin.

OBJECTIVE: To characterize the ocular changes associated with peginterferon alpha 2b (peg-IFN alpha-2b) and ribavirin therapy for chronic hepatitis C infection in HIV co-infected individuals. METHODS: A prospective, open-label trial treating HIV/hepatitis C (HCV) co-infected individuals with peg-IFN alpha-2b and ribavirin at the Warren Grant Magnusson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA. Twenty-three patients with a high mean CD4+ T-cell count were treated with peg-IFN alpha-2b and ribavirin and followed for 40 to 88 weeks. Ophthalmologic evaluations including visual acuity, visual field testing, color vision examination and indirect ophthalmoscopy were performed at baseline and every 3 months. RESULTS: Eight of the 23 patients (35%) developed ophthalmologic pathology, including cotton wool spots, cataracts, and two patients developed decreased color vision. These two patients regained their color vision, one after cessation of anti-HCV therapy. CONCLUSIONS: Although retinal pathologies have been reported in patients treated with interferon-alpha, they have not been reported during peg-IFN alpha-2b therapy nor in HIV/HCV co-infected patients. The incidence of serious ocular pathology associated with anti-HCV therapy may be very high and is probably associated with peg-IFN alpha-2b. Increased monitoring of patients treated with peg-IFN alpha-2b for retinal and visual changes is warranted.

Adult↗
PubMed1979

The ability of color defectives to judge signal lights at sea.

Measures were made of the ability of color-defective men to judge correctly the colors of navigation lights (red, green, or white) presented to them at night under realistic sea conditions. Eighty-one color-defective men were employed; they were categorized as to type and degree of defect using a battery of five color-vision tests. While the average performance of the color-defective men was considerably poorer than that of 24 color normals, there were large individual differences within each category of defect. Attempts to account for these differences in performance by variations in acuity, intelligence, and motivation failed. The extent to which the data can be accounted for by modern color-vision theory is discussed.

Color Vision Defects↗
PubMed1992

[The properties of visual functions and familial analysis in blue cone monochromatism].

The diagnosis of blue cone monochromatism (BCM) is based on severely affected color vision with preserved blue function, nearly absent photopic ERG, and a family pedigree compatible with X-linked inheritance. In the past, there has been no familial report of BCM in Japan. We found a Japanese family with BCM and studied the ocular findings of three affected members and a female carrier. Two of three affected members showed unique properties of BCM in their visual functions, including color vision and ERG. One affected member, a brother of their mother (43 years old), showed achromatic color vision. He had diabetic retinopathy and moderate cataract, which, might have disturbed his preserved blue cone function, resulting in the achromatic vision. A female carrier showed normal visual function, except that her photopic ERG was slightly reduced in amplitude.

Adult↗
PubMed1997

Color Night Vision: Opponent Processing in the Fusion of Visible and IR Imagery.

We describe here a means of fusing registered low-light visible and thermal infrared (IR) imagery to support realtime color night vision. Opponent processing, in the form of feedforward center-surround shunting neural networks, is used to contrast enhance and adaptively normalize both visible and IR imagery separately. Both positive and negative polarity ("on" and "off") enhanced IR imagery is then combined with the enhanced visible imagery to create two single-opponent color-contrast grayscale images. The opponent processed visible and opponent-color images (forming a set of three grayscale images) are then assigned directly to the red, green, blue (RGB) color space. Final manipulation of both hue and saturation is achieved in the hue, saturation, value (HSV) color space. Remarkably realistic color renderings of night scenes are obtained which may support perceptual "pop-out" of extended navigation cues and compact targets. Psychophysical testing on low contrast targets in natural dynamic scenes is called for in order to assess human performance using fused visible and IR imagery at night. Copyright 1996 Elsevier Science Ltd.

Journal Article↗
PubMedDate not supplied

The multifocal pattern electroretinogram in chloroquine retinopathy.

PURPOSE: Optimal screening for ocular toxicity caused by chloroquine and hydroxychloroquine is still controversial. With the multifocal pattern electroretinogram (mfPERG), a new electrophysiological technique has recently become available to detect early changes of ganglion cells. In this study this new technique is applied to a series of 10 patients seen consecutively receiving long-term chloroquine medication. METHODS: In 10 patients receiving chloroquine medication, clinical examination, Amsler visual field testing and computerized color vision testing were performed. If toxicity was suspected, automated perimetry was carried out. In addition, in all patients conventional pattern electroretinogram (PERG) and mfPERG testing were performed. RESULTS: On clinical examination 8 patients showed no chloroquine-associated maculopathy, while 2 patients did. Of these 2, only 1 reported abnormalities when viewing the Amsler chart, while automated perimetry showed typical, ring-like paracentral scotomas in both affected patients and color vision was significantly abnormal. In the normal patients, 4 of 8 had a mild color vision disturbance, which correlated to age-related macular changes. The amplitudes of the PERG and the central (approximately 10 degrees ) responses of the mfPERG were markedly reduced in chloroquine maculopathy, while the latencies were unchanged. The peripheral rings of mfPERG (ranging to 48 degrees ) were not affected by chloroquine toxicity. Both PERG and mfPERG were less affected by age-related macular changes. CONCLUSIONS: The reduction of PERG and central mfPERG responses in chloroquine maculopathy may help with the early detection of toxicity.

Adult↗