title: Low luminance deficit and night vision symptoms in intermediate age-related macular degeneration.
abstract: OBJECTIVE
  To determine the relationship between self-reported visual difficulties under low luminance conditions (night vision symptoms) and visual function measures in intermediate age-related macular degeneration (AMD).
  
  
  METHODS
  One hundred participants with bilateral intermediate AMD were examined in a prospective cross-sectional study with visual function measures including best-corrected visual acuity (BCVA), low luminance visual acuity (LLVA) and microperimetry in both eyes. A 10-item Night Vision Questionnaire (NVQ-10) was then used to determine the degree of self-reported night vision symptoms experienced by each participant. For analyses, low luminance deficit (LLD) was derived as the difference between LLVA and BCVA, and microperimetric mean sensitivity (MS; all points) and central sensitivity (CS; points within the central 1°) were determined. Rasch analysis was used to estimate the person measure of night vision symptoms, and its relationship with visual function parameters was determined.
  
  
  RESULTS
  NVQ-10 person measures were significantly associated with LLD (β coefficient=0.067, 95% CI 0.005 to 0.130, p=0.034), but not BCVA, LLVA, microperimetric MS or CS (p≥0.090). Participants with the highest degree of self-reported night vision symptoms (fourth quartile of person measure) had significantly worse LLD than those with the least difficulty (first quartile of person measure; p=0.019).
  
  
  CONCLUSIONS
  In individuals with bilateral intermediate AMD, LLD was associated with self-reported night vision symptoms, suggesting that this measure may better capture the visual difficulties experienced by these individuals under low luminance conditions than the conventional measure of photopic visual acuity.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Robyn H
authors.initials: RH
authors.lastname: Guymer
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Finger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009755:Night Blindness / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011446:Prospective Studies; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D015354:Vision, Low / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests
keywords: Degeneration; Macula; Psychophysics; Retina; Vision