title: Novel quantitative assessment of metamorphopsia in maculopathy.
abstract: OBJECTIVE
  Patients with macular disease often report experiencing metamorphopsia (visual distortion). Although typically measured with Amsler charts, more quantitative assessments of perceived distortion are desirable to effectively monitor the presence, progression, and remediation of visual impairment.
  
  
  METHODS
  Participants with binocular (n = 33) and monocular (n = 50) maculopathy across seven disease groups, and control participants (n = 10) with no identifiable retinal disease completed a modified Amsler grid assessment (presented on a computer screen with eye tracking to ensure fixation compliance) and two novel assessments to measure metamorphopsia in the central 5° of visual field. A total of 81% (67/83) of participants completed a hyperacuity task where they aligned eight dots in the shape of a square, and 64% (32/50) of participants with monocular distortion completed a spatial alignment task using dichoptic stimuli. Ten controls completed all tasks.
  
  
  RESULTS
  Horizontal and vertical distortion magnitudes were calculated for each of the three assessments. Distortion magnitudes were significantly higher in patients than controls in all assessments. There was no significant difference in magnitude of distortion across different macular diseases. There were no significant correlations between overall magnitude of distortion among any of the three measures and no significant correlations in localized measures of distortion.
  
  
  CONCLUSIONS
  Three alternative quantifications of monocular spatial distortion in the central visual field generated uncorrelated estimates of visual distortion. It is therefore unlikely that metamorphopsia is caused solely by retinal displacement, but instead involves additional top-down information, knowledge about the scene, and perhaps, cortical reorganization.
authors.affiliation: Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States.
authors.forename: Emily
authors.initials: E
authors.lastname: Wiecek
authors.affiliation: Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States Harvard Medical School, Department of Ophthalmology, Boston, Massachusetts, United States.
authors.forename: Kameran
authors.initials: K
authors.lastname: Lashkari
authors.affiliation: Institute of Ophthalmology, University College London, London, United Kingdom.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Dakin
authors.affiliation: Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States Harvard Medical School, Department of Ophthalmology, Boston, Massachusetts, United States Department of Psychology, Northeastern University, Boston, Massachusetts, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Bex
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008268:Macular Degeneration / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D033401:Microscopy, Acoustic; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D014787:Vision Tests; D014792:Visual Acuity; D014794:Visual Fields
keywords: low vision; macular degeneration; maculopathy; metamorphopsia; visual distortion