scholarly journals The Effect of Hypothyroidism on Color Contrast Sensitivity: A Prospective Study

2015 ◽  
Vol 4 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Mehtap Cakir ◽  
Banu Turgut Ozturk ◽  
Elif Turan ◽  
Gulsum Gonulalan ◽  
Ilker Polat ◽  
...  
Keyword(s):  
Contrast Sensitivity ◽  
Color Vision ◽  
Sensitivity Analyses ◽  
Contrast Threshold ◽  
Color Contrast ◽  
Cone Opsin ◽  
Yellow Color ◽  
Median Period ◽  
A Prospective Study ◽  
Retinal Cone

Background: Thyroid hormone has been shown to control retinal cone opsin expression, the protein of color vision, in adult rodents. Objectives: The aim of this study was to evaluate the effect of hypothyroidism on color contrast sensitivity in adult overt hypothyroid patients. Methods: Thirty-eight overt hypothyroid (31 females, 7 males) subjects and 20 euthyroid (16 females, 4 males) controls were studied prospectively. Color vision examination was performed by Chromatest, a software program analyzing the tritan (blue-yellow) color contrast threshold (tritan CCT) and protan (red-green) color contrast threshold (protan CCT). Color contrast sensitivity analyses of hypothyroid subjects were performed on admission and after L-thyroxine treatment when biochemical euthyroidism was achieved. Results: After a median period of 90 (90-210) days, 24 (19 females, 5 males) patients were euthyroid and eligible for a second color vision examination. Baseline tritan CCT and protan CCT values were significantly higher in the hypothyroid group compared to euthyroid controls, which clinically translates into impaired color contrast sensitivity (p < 0.001 and p < 0.001, respectively). There was a significant decrease in tritan CCT (p = 0.002) and protan CCT (p < 0.001) values in the hypothyroid group after euthyroidism was achieved, which denotes improvement in color contrast sensitivity. Conclusions: It is a novel finding of the current study that color contrast sensitivity is impaired in hypothyroidism and significantly improves after euthyroidism is achieved.

scholarly journals Mouse color and wavelength-specific luminance contrast sensitivity are non-uniform across visual space

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Daniel J Denman ◽  
Jennifer A Luviano ◽  
Douglas R Ollerenshaw ◽  
Sissy Cross ◽  
Derric Williams ◽  
...  
Keyword(s):  
Contrast Sensitivity ◽  
Visual Space ◽  
Color Discrimination ◽  
Luminance Contrast ◽  
Neural Systems ◽  
Mouse Retina ◽  
Color Contrast ◽  
Cone Opsin ◽  
Cell Type Specific ◽  
Cone Opsins

Mammalian visual behaviors, as well as responses in the neural systems underlying these behaviors, are driven by luminance and color contrast. With constantly improving tools for measuring activity in cell-type-specific populations in the mouse during visual behavior, it is important to define the extent of luminance and color information that is behaviorally accessible to the mouse. A non-uniform distribution of cone opsins in the mouse retina potentially complicates both luminance and color sensitivity; opposing gradients of short (UV-shifted) and middle (blue/green) cone opsins suggest that color discrimination and wavelength-specific luminance contrast sensitivity may differ with retinotopic location. Here we ask how well mice can discriminate color and wavelength-specific luminance changes across visuotopic space. We found that mice were able to discriminate color and were able to do so more broadly across visuotopic space than expected from the cone-opsin distribution. We also found wavelength-band-specific differences in luminance sensitivity.

Cone visual pigments of aquatic mammals

2005 ◽  
Vol 22 (6) ◽  
pp. 873-879 ◽  
Author(s):  
LUCY A. NEWMAN ◽  
PHYLLIS R. ROBINSON
Keyword(s):  
Color Vision ◽  
Mammalian Cells ◽  
Marine Mammals ◽  
Light Availability ◽  
Splice Site Mutation ◽  
Harbor Seal ◽  
Site Mutation ◽  
Cetacean Species ◽  
Cone Opsin ◽  
Aquatic Mammals

It has long been hypothesized that the visual systems of animals are evolutionarily adapted to their visual environment. The entrance many millions of years ago of mammals into the sea gave these new aquatic mammals completely novel visual surroundings with respect to light availability and predominant wavelengths. This study examines the cone opsins of marine mammals, hypothesizing, based on previous studies [Fasick et al. (1998) and Levenson & Dizon (2003)], that the deep-dwelling marine mammals would not have color vision because the pressure to maintain color vision in the dark monochromatic ocean environment has been relaxed. Short-wavelength-sensitive (SWS) and long-wavelength-sensitive (LWS) cone opsin genes from two orders (Cetacea and Sirenia) and an additional suborder (Pinnipedia) of aquatic mammals were amplified from genomic DNA (for SWS) and cDNA (for LWS) by PCR, cloned, and sequenced. All animals studied from the order Cetacea have SWS pseudogenes, whereas a representative from the order Sirenia has an intact SWS gene, for which the corresponding mRNA was found in the retina. One of the pinnipeds studied (harp seal) has an SWS pseudogene, while another species (harbor seal) appeared to have an intact SWS gene. However, no SWS cone opsin mRNA was found in the harbor seal retina, suggesting a promoter or splice site mutation preventing transcription of the gene. The LWS opsins from the different species were expressed in mammalian cells and reconstituted with the 11-cis-retinal chromophore in order to determine maximal absorption wavelengths (λmax) for each. The deeper dwelling Cetacean species had blue shifted λmax values compared to shallower-dwelling aquatic species. Taken together, these findings support the hypothesis that in the monochromatic oceanic habitat, the pressure to maintain color vision has been relaxed and mutations are retained in the SWS genes, resulting in pseudogenes. Additionally, LWS opsins are retained in the retina and, in deeper-dwelling animals, are blue shifted in λmax.

The visual pigments of the bottlenose dolphin (Tursiops truncatus)

1998 ◽  
Vol 15 (4) ◽  
pp. 643-651 ◽  
Author(s):  
JEFFRY I. FASICK ◽  
THOMAS W. CRONIN ◽  
DAVID M. HUNT ◽  
PHYLLIS R. ROBINSON
Keyword(s):  
Color Vision ◽  
Bottlenose Dolphin ◽  
Visual Pigments ◽  
Nucleotide Position ◽  
Long Wavelength ◽  
Terrestrial Mammals ◽  
Cone Opsin ◽  
Cone Pigments ◽  
The Common

To assess the dolphin's capacity for color vision and determine the absorption maxima of the dolphin visual pigments, we have cloned and expressed the dolphin opsin genes. On the basis of sequence homology with other mammalian opsins, a dolphin rod and long-wavelength sensitive (LWS) cone opsin cDNAs were identified. Both dolphin opsin cDNAs were expressed in mammalian COS-7 cells. The resulting proteins were reconstituted with the chromophore 11-cis-retinal resulting in functional pigments with absorption maxima (λmax) of 488 and 524 nm for the rod and cone pigments respectively. These λmax values are considerably blue shifted compared to those of many terrestrial mammals. Although the dolphin possesses a gene homologous to other mammalian short-wavelength sensitive (SWS) opsins, it is not expressed in vivo and has accumulated a number of deletions, including a frame-shift mutation at nucleotide position 31. The dolphin therefore lacks the common dichromatic form of color vision typical of most terrestrial mammals.

scholarly journals Visual Acuity, Contrast Sensitivity and Color Vision Three Years After Iodine-125 Brachytherapy for Choroidal and Ciliary Body Melanoma

2015 ◽  
Vol 9 (1) ◽  
pp. 131-135 ◽  
Author(s):  
Irena Tsui ◽  
Robert M Beardsley ◽  
Tara A McCannel ◽  
Scott C Oliver ◽  
Melissa W Chun ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Color Vision ◽  
Ciliary Body ◽  
Case Series ◽  
Vision Measurement ◽  
Corrected Visual Acuity ◽  
Iodine 125 ◽  
Decrease In Visual Acuity ◽  
Ciliary Body Melanoma

Purpose : To report visual acuity, contrast sensitivity and color vision prior to, 1 year after, 2 years after and 3 years after iodine-125 brachytherapy for choroidal and ciliary body melanoma (CCM). Design : Prospective interventional case series. Participants : Thirty-seven patients (37 eyes) with CCM. Methods : Patients had best-corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity, Pelli-Robson contrast sensitivity and Hardy-Rand-Rittler color vision measurement; comprehensive ophthalmology examination; optical coherence tomography; and ultrasonography at baseline prior to, 1 year after, 2 years after and 3 years after I-125 brachytherapy. Main Outcome Measures : Visual acuity, contrast sensitivity and color vision prior to, 1 year after, 2 years after and 3 years after brachytherapy. Results : Nineteen (19) men and 18 women with mean age of 58 years (SD 13, range 30-78) prior to, 1 year after, 2 years after and 3 years after brachytherapy had mean best-corrected visual acuity of 77 letters (20/32), 65 letters (20/50), 56 letters (20/80) and 47 letters (20/125); contrast sensitivity of 30, 26, 22 and 19 letters; color vision of 26, 20, 17 and 14 test figures, respectively. Decrease in visual acuity, contrast sensitivity and color vision was statistically significant from baseline at 1 year, 2 years, and 3 years after brachytherapy. Decreased acuity at 3 years was associated with mid-choroid and macula melanoma location, ≥ 4.1 mm melanoma height, radiation maculopathy and radiation optic neuropathy. Conclusion : 1, 2 and 3 years after brachytherapy, eyes with CCM had significantly decreased visual acuity, contrast sensitivity and color vision.

scholarly journals Paternal body mass index before conception associated with offspring's birth weight in Chinese population: a prospective study

2021 ◽  
Author(s):  
Renying Xu ◽  
Weixiu Zhao ◽  
Tao Tan ◽  
Haojie Li ◽  
Yanping Wan
Keyword(s):  
Body Mass Index ◽  
Body Weight ◽  
Birth Weight ◽  
Body Mass ◽  
Sensitivity Analyses ◽  
Gestational Weight ◽  
A Prospective Study ◽  
The Relationship ◽  
Multivariable Adjustment ◽  
Chinese Mother

Whether paternal epigenetic information of nutrition might be inherited by their offspring remained unknown. evaluate the relationship between preconception paternal body weight and their offspring's birth weight in 1,810 Chinese mother-father-baby trios. Information on paternal and maternal preconception body weight and height was collected via a self-reported questionnaire. Birth weight was collected from medical records. Paternal preconception body weight was associated with offspring's birth weight (p trend=0.02) after multivariable adjustment. Each standard deviation increment of paternal body mass index was associated with an additional 29.6 g increase of birth weight (95% confident interval: 5.7g, 53.5g). The association was more pronounced in male neonates, and neonates with overweight mothers, and with mothers who gained excessive gestational weight, compared to their counterparts (all p interaction<0.05). Sensitivity analyses showed similar pattern to that of the main analysis. Paternal preconception body weight was associated with birth weight of their offspring.

scholarly journals A Clinical Study of Optic Disc Edema in a Tertiary Eye Center of Nepal

2019 ◽  
Vol 11 (2) ◽  
pp. 122-129
Author(s):  
Anil Parajuli ◽  
Ananda Kumar Sharma ◽  
Sanjeeta Sitaula
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Color Vision ◽  
Optic Disc ◽  
Blind Spot ◽  
Optic Disc Edema ◽  
Disc Edema ◽  
Vision Defect ◽  
Common Causes ◽  
Life Threatening

Purpose: To evaluate the etiology and clinical presentation of cases with optic disc edema presenting to a tertiary eye center of Nepal. Background: The etiology of optic disc edema ranges from relatively benign to potentially sight and life threatening conditions. Till date very few studies have been done on disc edema in Nepal. Method: The authors conducted a prospective, descriptive study at B.P. Koirala Lions Center for Ophthalmic Studies (BPKLCOS), Nepal. All cases with disc edema presenting to the out patient department (OPD) from January 1, 2014 to June 30, 2015 were included in the study. Results: Total 112 patients were included in the study, out of which diagnosis could be established in 99. The mean age of the patients was 32.54 ± 13.97 years with the majority being female. The most common cause of disc edema was idiopathic intracranial hypertension (IIH) (37.5%,). Majority of the patients complained of isolated diminution of vision (38.4%). Among the eyes affected, 78.3% had best corrected visual acuity (BCVA) 6/6-6/18, 36.6% had color vision defect and 31.4% had reduced contrast sensitivity. The most common visual field defect was isolated enlarged blind spot (39.7 %). Conclusion: IIH followed by optic neuritis (ON) are the most common causes of disc edema. Conditions with disc edema mainly affect the age group 21-40 years with females affected 2.5 times more than males. Visual acuity, color vision and contrast sensitivity are deranged in majority of cases of ON and normal in majority of cases of IIH.

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