Molecular Genetics of Color Vision and Color Vision Defects
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Sensitivities in Older Eyes with Good Acuity: Cross-Sectional Norms
Sensitivities in Older Eyes With Good Acuity: Cross-Sectional Norms Alvin Eisner,*f Susan A. Fleming,*! Michael L. Kleins and W. Manning Mauldinf We measured several indices of foveal visual function for a large group of people aged 60 and older. The data reported in this paper are from individuals who had good acuity in each eye and met a number of other criteria for good ocular health. For each index, we described the rate of cross-sectional change with age using linear regression statistics. We found age-related change for eyes having 20/20 or better acuity to exist for several different indices. Sensitivity mediated by the blue-sensitive cones decreased with age, as expected. However, the rate of decrease was faster for females than for males. At least part of the difference was associated with different rates of lenticular change. Absolute sensitivity at long wavelengths also decreased with age, but at the same rate for each sex. Rayleigh color matches changed with age in a manner consistent with underlying age-related decreases of effective foveal cone photopigment density. However, not all indices showed age-dependent changes. For instance, the time constant describing the rate of photopic dark adaptation did not appear to change with age. Invest Ophthalmol Vis Sci 28:1824-1831, 1987 Human visual function changes with age. Cross- criteria for good ocular health in each eye. In particu- sectional age-related changes have been reported for lar, we have tested people having good acuity in each Snellen acuity,1 spatial2"4 and temporal4 contrast sen- eye. -
Ametropia and Emmetropization in CNGB3 Achromatopsia
Retina Ametropia and Emmetropization in CNGB3 Achromatopsia Mette Kjøbæk Gundestrup Andersen1 and Line Kessel1,2 1Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet-Glostrup, Glostrup, Denmark 2Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark Correspondence: Mette K.G. PURPOSE. Emmetropization is the process of adjusting ocular growth to the focal plane Andersen, Department of in order to achieve a clear image. Chromatic light may be involved as a cue to guide Ophthalmology, Copenhagen this process. Achromats are color blind and lack normal cone function; they are often University Hospital, described as being hyperopic, indicating a failure to emmetropize. We aim to describe Rigshospitalet-Glostrup, Valdemar the refraction and refractive development in a population of genetically characterized Hansens Vej 1-23, 2600 Glostrup, Denmark; achromats. [email protected]. METHODS. Refractive error data were collected retrospectively from 28 medical records CNGB3 Received: August 23, 2020 of c.1148delC homozygous achromats. The distribution of spherical equivalent Accepted: January 18, 2021 refractive error (SER) and spherical error was analyzed in adults. The refractive develop- Published: February 9, 2021 ment in children was analyzed by documenting astigmatic refractive error and calculating Citation: Andersen MKG, Kessel L. median SER in 1-year age groups and by analyzing the individual development when Ametropia and emmetropization in possible. CNGB3 Invest achromatopsia. RESULTS. The distribution of SER and spherical error resembled a Gaussian distribution, Ophthalmol Vis Sci. 2021;62(2):10. indicating that emmetropization was disturbed in achromats, but we found indication of https://doi.org/10.1167/iovs.62.2.10 some decrease in SER during the first years of childhood. -
ERG), Molecular and Behavioral Studies
Vision Research 38 (1998) 3377–3385 Severity of color vision defects: electroretinographic (ERG), molecular and behavioral studies M.A. Crognale a,b,*, D.Y. Teller a,c, A.G. Motulsky d,e, S.S. Deeb d,e a Department of Psychology, Uni6ersity of Washington, Box 351525, Seattle, WA 98195-1525, USA b Department of Ophthalmology, Uni6ersity of Washington, Seattle, WA, USA c Department of Physiology/Biophysics, Uni6ersity of Washington, Seattle, WA, USA d Department of Genetics, Uni6ersity of Washington, Seattle, WA, USA e Department of Medicine, Uni6ersity of Washington, Seattle, WA, USA Received 10 July 1997; received in revised form 29 October 1997 Abstract Earlier research on phenotype/genotype relationships in color vision has shown imperfect predictability of color matching from the photopigment spectral sensitivities inferred from molecular genetic analysis. We previously observed that not all of the genes of the X-chromosome linked photopigment gene locus are expressed in the retina. Since sequence analysis of DNA does not necessarily reveal which of the genes are expressed into photopigments, we used ERG spectral sensitivities and adaptation measurements to assess expressed photopigment complement. Many deuteranomalous subjects had L, M, and L–M hybrid genes. The ERG results showed that M pigment is not present in measurable quantities in deutan subjects. Using these results to determine gene expression improved the correlations between inferred pigment separation and color matching. Furthermore, we found a subject who had normal L and M genes and normal proximal promoter sequences, yet he had a single photopigment (M) by ERG and tested as a protanope. These results demonstrate the utility of ERG measurements in studies of molecular genetics of color vision deficiencies, and further support the conclusion that not all genes are expressed in color deficient subjects. -
Color Blindness LEVELED BOOK • W a Reading A–Z Level W Leveled Book Word Count: 1,349 Color Blindness Connections Writing Choose Two Forms of Color Blindness
Color Blindness LEVELED BOOK • W A Reading A–Z Level W Leveled Book Word Count: 1,349 Color Blindness Connections Writing Choose two forms of color blindness. Write a report that compares the two conditions and their effects on a person’s life. Math Research the statistics about the number of people with the various forms of color blindness in your country. Organize your results in a pie chart. • W Q •T Written by Cheryl Reifsnyder Visit www.readinga-z.com for thousands of books and materials. www.readinga-z.com Words to Know Color ancestry molecules complementary photopigments cone cells prism Blindness defects retina genetic disorder rod cells hereditary wavelengths Photo Credits: Front cover, Back cover: © pretoperola/123RF; title page (Both): © shironosov/ iStock/Thinkstock; page 3: © Véronique Burger/Science Source; page 4 (Both): © Michael Shake/Dreamstime.com; page 5: © Designua/Dreamstime.com; page 6 (top): © Gunilla Elam/Science Source; page 6 (Bottom): © Steve Gschmeissner/Science Source; page 7 (Both): © Ted Kinsman/ Science Source; page 8 (left, Both): © anatchant/iStock/Thinkstock; page 8 (center, Both): © Nadezhda Bolotina/Hemera/Thinkstock; page 8 (right, Both): © iremphotography/iStock/Thinkstock; page 9 (all): © Popartic/iStock Editorial/Thinkstock; page 10: © RVN/Alamy Stock Photo; page 12: © Alexander Kaludov/123RF; page 13: © EnChroma; page 14: © Neitz LaBoratory; page 15: © Phanie/Alamy Stock Photo Written by Cheryl Reifsnyder www.readinga-z.com Focus Question Color Blindness Level W Leveled Book Correlation © Learning A–Z LEVEL W Written By Cheryl Reifsnyder What causes color blindness, and how Fountas & Pinnell S can it affect a person’s life? All rights reserved. -
RETINAL DISORDERS Eye63 (1)
RETINAL DISORDERS Eye63 (1) Retinal Disorders Last updated: May 9, 2019 CENTRAL RETINAL ARTERY OCCLUSION (CRAO) ............................................................................... 1 Pathophysiology & Ophthalmoscopy ............................................................................................... 1 Etiology ............................................................................................................................................ 2 Clinical Features ............................................................................................................................... 2 Diagnosis .......................................................................................................................................... 2 Treatment ......................................................................................................................................... 2 BRANCH RETINAL ARTERY OCCLUSION ................................................................................................ 3 CENTRAL RETINAL VEIN OCCLUSION (CRVO) ..................................................................................... 3 Pathophysiology & Etiology ............................................................................................................ 3 Clinical Features ............................................................................................................................... 3 Diagnosis ......................................................................................................................................... -
The Genetics of Normal and Defective Color Vision
Vision Research xxx (2011) xxx–xxx Contents lists available at ScienceDirect Vision Research journal homepage: www.elsevier.com/locate/visres Review The genetics of normal and defective color vision Jay Neitz ⇑, Maureen Neitz University of Washington, Dept. of Ophthalmology, Seattle, WA 98195, United States article info a b s t r a c t Article history: The contributions of genetics research to the science of normal and defective color vision over the previ- Received 3 July 2010 ous few decades are reviewed emphasizing the developments in the 25 years since the last anniversary Received in revised form 25 November 2010 issue of Vision Research. Understanding of the biology underlying color vision has been vaulted forward Available online xxxx through the application of the tools of molecular genetics. For all their complexity, the biological pro- cesses responsible for color vision are more accessible than for many other neural systems. This is partly Keywords: because of the wealth of genetic variations that affect color perception, both within and across species, Color vision and because components of the color vision system lend themselves to genetic manipulation. Mutations Cone photoreceptor and rearrangements in the genes encoding the long, middle, and short wavelength sensitive cone pig- Colorblindness Cone mosaic ments are responsible for color vision deficiencies and mutations have been identified that affect the Opsin genes number of cone types, the absorption spectra of the pigments, the functionality and viability of the cones, Evolution and the topography of the cone mosaic. The addition of an opsin gene, as occurred in the evolution of pri- Comparative color vision mate color vision, and has been done in experimental animals can produce expanded color vision capac- Cone photopigments ities and this has provided insight into the underlying neural circuitry. -
Theoretical Part Eye Examinations 1
Name and Surrname number Study group Theoretical part Eye examinations 1. Astigmatism Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina. Astigmatism can sometimes be asymptomatic, while higher degrees of astigmatism may cause symptoms such as blurry vision, squinting, eye strain, fatigue, or headaches. Types Regular astigmatism: Principal meridians are perpendicular. Simple astigmatism – the first focal line is on the retina, while the second is located behind the retina, or, the first focal line is in front of the retina, while the second is on the retina. Compound astigmatism – both focal lines are located behind or before the retina. Mixed astigmatism – focal lines are on both sides of the retina (straddling the retina). Irregular astigmatism: Principal meridians are not perpendicular. This type cannot be corrected by a lens. Tests Objective Refractometer, autorefractometer Placido keratoscope – A placido keratoscope consists of a handle and a circular part with a hole in the middle. The hole with a magnifying glass is viewed from a distance of 10–15 cm to the patients cornea. In the 200 mm wide circular portion there are concentric alternating black and white circles. They reflect the patient’s cornea. In the event of astigmatism, a deformation appears at the corresponding location. Sciascope Ophthalmometry Subjective Fuchs figure – This is a tool for evaluating astigmatism where examinee stands up against a pattern of circular shape (circular or striped rectangles) and fixes his/her gaze on the center of the pattern with one open eye. -
Genes in Eyecare Geneseyedoc 3 W.M
Genes in Eyecare geneseyedoc 3 W.M. Lyle and T.D. Williams 15 Mar 04 This information has been gathered from several sources; however, the principal source is V. A. McKusick’s Mendelian Inheritance in Man on CD-ROM. Baltimore, Johns Hopkins University Press, 1998. Other sources include McKusick’s, Mendelian Inheritance in Man. Catalogs of Human Genes and Genetic Disorders. Baltimore. Johns Hopkins University Press 1998 (12th edition). http://www.ncbi.nlm.nih.gov/Omim See also S.P.Daiger, L.S. Sullivan, and B.J.F. Rossiter Ret Net http://www.sph.uth.tmc.edu/Retnet disease.htm/. Also E.I. Traboulsi’s, Genetic Diseases of the Eye, New York, Oxford University Press, 1998. And Genetics in Primary Eyecare and Clinical Medicine by M.R. Seashore and R.S.Wappner, Appleton and Lange 1996. M. Ridley’s book Genome published in 2000 by Perennial provides additional information. Ridley estimates that we have 60,000 to 80,000 genes. See also R.M. Henig’s book The Monk in the Garden: The Lost and Found Genius of Gregor Mendel, published by Houghton Mifflin in 2001 which tells about the Father of Genetics. The 3rd edition of F. H. Roy’s book Ocular Syndromes and Systemic Diseases published by Lippincott Williams & Wilkins in 2002 facilitates differential diagnosis. Additional information is provided in D. Pavan-Langston’s Manual of Ocular Diagnosis and Therapy (5th edition) published by Lippincott Williams & Wilkins in 2002. M.A. Foote wrote Basic Human Genetics for Medical Writers in the AMWA Journal 2002;17:7-17. A compilation such as this might suggest that one gene = one disease. -
Comprehensive Pediatric Eye and Vision Examination
American Optometric Association – Peer/Public Review Document 1 2 3 EVIDENCE-BASED CLINICAL PRACTICE GUIDELINE 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Comprehensive 18 Pediatric Eye 19 and Vision 20 Examination 21 22 For Peer/Public Review May 16, 2016 23 American Optometric Association – Peer/Public Review Document 24 OPTOMETRY: THE PRIMARY EYE CARE PROFESSION 25 26 The American Optometric Association represents the thousands of doctors of optometry 27 throughout the United States who in a majority of communities are the only eye doctors. 28 Doctors of optometry provide primary eye care to tens of millions of Americans annually. 29 30 Doctors of optometry (O.D.s/optometrists) are the independent primary health care professionals for 31 the eye. Optometrists examine, diagnose, treat, and manage diseases, injuries, and disorders of the 32 visual system, the eye, and associated structures, as well as identify related systemic conditions 33 affecting the eye. Doctors of optometry prescribe medications, low vision rehabilitation, vision 34 therapy, spectacle lenses, contact lenses, and perform certain surgical procedures. 35 36 The mission of the profession of optometry is to fulfill the vision and eye care needs of the 37 public through clinical care, research, and education, all of which enhance quality of life. 38 39 40 Disclosure Statement 41 42 This Clinical Practice Guideline was funded by the American Optometric Association (AOA), 43 without financial support from any commercial sources. The Evidence-Based Optometry 44 Guideline Development Group and other guideline participants provided full written disclosure 45 of conflicts of interest prior to each meeting and prior to voting on the strength of evidence or 46 clinical recommendations contained within this guideline. -
OCULAR GENE THERAPY TRIALS ADVANCE Results of the First Phase 3 Trial Were Announced
OCULAR GENE THERAPY TRIALS ADVANCE Results of the first phase 3 trial were announced. BY ARON SHAPIRO INNOVATIONS IN RETINA INNOVATIONS “We used to think that our fate was in our AAV FACILITATES GENE DELIVERY stars, but now we know that, in large measure, The nonpathogenic adeno-associated virus (AAV) has our fate is in our genes.” to date been a safe and effective vector for gene delivery. –James Watson1 The recombinant AAV (rAAV) vector has demonstrated increased specificity and efficiency in ocular AAV-mediated Genetic alterations are known to be respon- gene therapy interventions. Recombinant AAV2 (rAAV2) sible for numerous diseases, and so it follows vectors used for gene therapy are derived from the wild-type logically that the best cures for these diseases virus by deleting the entire viral coding region and replac- might lie in correcting genetic anomalies by the process of ing it with the reporter or therapeutic transgene. Combined gene therapy. This approach involves the introduction of AAV serotypes have also been developed. This diversity genes into existing cells in attempts to prevent or cure a of serotypes may lead to more specific and more efficient wide range of diseases previously thought to be incurable.1 transduction. However, successful and efficient transfection Posterior segment disorders are challenging to treat, and of particular cell types in the eye still depends on other fac- current therapies have numerous shortcomings. Many are tors, such as the AAV titer, the site of injection, the amount invasive, run the risk of complications, offer only short-term of passenger DNA, and the specific gene promoters where relief from symptoms, or are unable to directly treat vision transcription initiation takes place.2 loss. -
Acquired Colour Vision Defects in Glaucoma—Their Detection and Clinical Significance
1396 Br J Ophthalmol 1999;83:1396–1402 Br J Ophthalmol: first published as 10.1136/bjo.83.12.1396 on 1 December 1999. Downloaded from PERSPECTIVE Acquired colour vision defects in glaucoma—their detection and clinical significance Mireia Pacheco-Cutillas, Arash Sahraie, David F Edgar Colour vision defects associated with ocular disease have The aims of this paper are: been reported since the 17th century. Köllner1 in 1912 + to provide a review of the modern literature on acquired wrote an acute description of the progressive nature of col- colour vision in POAG our vision loss secondary to ocular disease, dividing defects + to diVerentiate the characteristics of congenital and into “blue-yellow” and “progressive red-green blindness”.2 acquired defects, in order to understand the type of This classification has become known as Köllner’s rule, colour vision defect associated with glaucomatous although it is often imprecisely stated as “patients with damage retinal disease develop blue-yellow discrimination loss, + to compare classic clinical and modern methodologies whereas optic nerve disease causes red-green discrimina- (including modern computerised techniques) for tion loss”. Exceptions to Köllner’s rule34 include some assessing visual function mediated through chromatic optic nerve diseases, notably glaucoma, which are prima- mechanisms rily associated with blue-yellow defects, and also some reti- + to assess the eVects of acquired colour vision defects on nal disorders such as central cone degeneration which may quality of life in patients with POAG. result in red-green defects. Indeed, in some cases, there might be a non-specific chromatic loss. Comparing congenital and acquired colour vision Colour vision defects in glaucoma have been described defects since 18835 and although many early investigations Congenital colour vision deficiencies result from inherited indicated that red-green defects accompanied glaucoma- cone photopigment abnormalities. -
Colour Vision Deficiency
Eye (2010) 24, 747–755 & 2010 Macmillan Publishers Limited All rights reserved 0950-222X/10 $32.00 www.nature.com/eye Colour vision MP Simunovic REVIEW deficiency Abstract effective "treatment" of colour vision deficiency: whilst it has been suggested that tinted lenses Colour vision deficiency is one of the could offer a means of enabling those with commonest disorders of vision and can be colour vision deficiency to make spectral divided into congenital and acquired forms. discriminations that would normally elude Congenital colour vision deficiency affects as them, clinical trials of such lenses have been many as 8% of males and 0.5% of femalesFthe largely disappointing. Recent developments in difference in prevalence reflects the fact that molecular genetics have enabled us to not only the commonest forms of congenital colour understand more completely the genetic basis of vision deficiency are inherited in an X-linked colour vision deficiency, they have opened the recessive manner. Until relatively recently, our possibility of gene therapy. The application of understanding of the pathophysiological basis gene therapy to animal models of colour vision of colour vision deficiency largely rested on deficiency has shown dramatic results; behavioural data; however, modern molecular furthermore, it has provided interesting insights genetic techniques have helped to elucidate its into the plasticity of the visual system with mechanisms. respect to extracting information about the The current management of congenital spectral composition of the visual scene. colour vision deficiency lies chiefly in appropriate counselling (including career counselling). Although visual aids may Materials and methods be of benefit to those with colour vision deficiency when performing certain tasks, the This article was prepared by performing a evidence suggests that they do not enable primary search of Pubmed for articles on wearers to obtain normal colour ‘colo(u)r vision deficiency’ and ‘colo(u)r discrimination.