PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Color Perception Tests”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed1979

Typical and atypical monochromacy studied by specific quantitative perimetry.

Two blue cone monochromats and four rod monochromats have been studied by increment threshold measurements applying the Stiles' principle. Some rudimentary colour discrimination was reported by the blue cone monochromats. One patient showed good discrimination between short- and middle-wavelength lights in matching experiments using the Nagel II apparatus. His neutral band in the spectrum was at lambda = 485--495 nm. Dichromatic vision could not be proved in the other patient. The blue cone monochromats also had good responding blue mechanism in the periphery. Indication of cone activity other than blue cones is found in both kinds of monochromats; these cones being probably of the rhodopsin-cone type (pi0 cones). The conclusions are drawn that the inhibitory effect of the pi0 cones upon the rod mechanism may account for the differences shown by our two blue cone monochromats as to visual acuity, nystagmus and photophobia. Likewise, their differences regarding dichromatic vision may be explained by an unequal number of pi0 cones in their retinas rather than by differences in their blue mechanisms.

Adolescent↗
PubMed1979

Eight cases of congenital achromatopsia with amblyopia in two pedigrees from Northern Sweden.

Two families from northern Sweden with a total of 8 patients with typical symptoms of congenital achromatopsia with amblyopia were studied. In one of the families 4 affected children (3 brothers and 1 sister) also showed pallor of the optic discs and marked astigmatism. The transmission of the disease was consistent with an autosomal recessive inheritance in both families. The study confirmed that complete and incomplete achromatopsia might be different expressions of the same gene. Six out or 13 near relatives of the achromatic patients showed minor colour vision defects, suggesting a tendency towards heterozygotic manifestation of the gene.

Adolescent↗
PubMed1991

Electroretinograms in patients with achromatopsia.

Eleven patients with X-linked and 9 patients with autosomal recessive achromatopsia were examined with full-field electroretinograms. In the standard full-field ERG's, normal rod responses were obtained, but the amplitude of the cone b-waves was not detectable. With computer averaging and narrow bandpass filtering, residual cone b-wave responses could be detected in 10 of the 20 patients. The residual cone b-wave amplitudes were markedly different in the 3 families with X-linked achromatopsia. In two of them, residual cone b-wave responses were seen in all patients examined. In contrast, such responses were seen only in 2 of 7 patients in the third family. There were also differences in other clinical observations (mainly in the visual acuity and refractive error) and we therefore suggest that there are at least two forms of X-linked achromatopsia. The ratios of the cone response amplitudes to 30 Hz flickering orange and blue-green light suggested that the defect in the X-linked achromatopsia patients was of the protanope type, whereas in the autosomal patients, both the protanope and the deutanope type was seen. In conclusion, measurements of the residual cone b-wave amplitude responses are of diagnostic and may possibly be of prognostic value when examining children and other members of families with achromatopsia.

Adult↗
PubMed1968

Prereceptor colour vision distortions in protanomalous trichromacy.

1. Scotopic luminosity and fundus spectral reflexion in the protanomalous fail to confirm predictions made from the hypothesis that protanomalous photopic luminosity loss is due to an inert red-absorbing filter in his ocular media.2. If it were supposed that the luminosity losses were due to a reduced number of normal red cones, the anomaloscope mismatches could result from a prereceptor distortion such as a reduced concentration of macular pigment or a tilt of the foveal cones. Experiments exclude these two possibilities.3. An anomaloscope is described which makes it possible to measure colour-matching properties of the protanomalous eye by transcleral illumination. Such measurements exclude, as a class, hypotheses which attribute protanomalous colour-matching distortions to an inert filter localized anywhere between the cone outer segment and the cornea.4. It is concluded that the absorption spectrum of at least one of the three cone visual pigments of the protanomalous eye must differ from that of the pigments of the normal fovea.

Color Perception↗
PubMed2004

Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features.

AIM: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded. RESULTS: Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score. CONCLUSIONS: Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.

Adolescent↗
PubMed1997

Partial reversal of protan and tritan colour defects with inhaled oxygen in insulin dependent diabetic subjects.

AIMS: Abnormalities in colour perception occur early in the development of diabetic retinopathy. Whether these changes can be influenced by increasing circulating oxygen saturation was studied in comparison with non-diabetic controls. METHODS: Protan and tritan colour thresholds were measured using a computer graphics system in 37 insulin dependent diabetic subjects, with no or minimal background retinopathy, and 27 matched controls. Colour thresholds were performed after subjects inhaled either gaseous air or 100% oxygen for a minimum of 5 minutes. RESULTS: Diabetic subjects had higher colour vision thresholds when inhaling air when compared with controls (protan (mean 3.93 (SEM 0.39), v 2.36 (0.16), p < 0.0002) and tritan (8.15 (0.62) v 5.42 (0.31), p < 0.002)). The colour vision thresholds observed in diabetic subjects inhaling air fell when they inhaled oxygen (protan (3.93 (0.39) v 3.57 (0.33), p < 0.025) and tritan (8.15 (0.62) v 7.35 (0.59), p < 0.005)). No fall in colour thresholds was seen in non-diabetic controls who inhaled oxygen. CONCLUSION: A small improvement in the colour vision thresholds was observed using computer graphics in diabetic subjects, with minimal or no retinopathy, who inhaled oxygen. This study supports a hypothesis that reduced retinal oxygenation contributes to the colour vision defects in diabetes.

Adult↗