TY - JOUR
T1 - The Effects of Blur and Eccentric Viewing on Adult Acuity for Pediatric Tests
T2 - Implications for Amblyopia Detection
AU - Formankiewicz, Monika A.
AU - Waugh, Sarah J.
N1 - Copyright:
This record is sourced from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
PY - 2013/10/1
Y1 - 2013/10/1
N2 - PURPOSE: The detection of amblyopia in children relies on an accurate assessment of visual acuity. Visual deficits in anisometropic and strabismic amblyopia are different, but the influence of chart design, in particular position, and type of crowding features on visual acuity in the two types of amblyopia, is not clear. Certain aspects of amblyopic spatial vision are mimicked in healthy individuals by imposing increasing levels of blur and retinal eccentricity. We measured the effects of these conditions on visual acuity in healthy adults, with crowded and uncrowded vision tests.METHODS: Visual acuity was measured under conditions of blur (0-4 D) and eccentric viewing (0-5 degrees) using high-contrast optotypes derived from common children's acuity charts. Optotypes were presented in isolation, in commercially available crowded configurations, and in configurations with closer target-flanker separations than those currently available.RESULTS: Dioptric blur had similar degradative effects on crowded and isolated visual acuity (P > 0.05), whereas eccentric viewing resulted in a larger deterioration of visual acuity for crowded tests (E2 of 0.86-1.06) than for isolated optotypes (E2 of 1.57-1.72) (P < 0.05). Maximum crowding effects occurred for closer target-flanker separations than those currently used commercially.CONCLUSIONS: In so far as blur and eccentric viewing mimic spatial acuity deficits in amblyopia, the results suggest that crowded tests might be of limited value in the detection of anisometropic amblyopia, but should be valuable in the detection of strabismic amblyopia. Crowding effects would be greater if flanking features were placed closer to the target than they currently are in commercially available charts.
AB - PURPOSE: The detection of amblyopia in children relies on an accurate assessment of visual acuity. Visual deficits in anisometropic and strabismic amblyopia are different, but the influence of chart design, in particular position, and type of crowding features on visual acuity in the two types of amblyopia, is not clear. Certain aspects of amblyopic spatial vision are mimicked in healthy individuals by imposing increasing levels of blur and retinal eccentricity. We measured the effects of these conditions on visual acuity in healthy adults, with crowded and uncrowded vision tests.METHODS: Visual acuity was measured under conditions of blur (0-4 D) and eccentric viewing (0-5 degrees) using high-contrast optotypes derived from common children's acuity charts. Optotypes were presented in isolation, in commercially available crowded configurations, and in configurations with closer target-flanker separations than those currently available.RESULTS: Dioptric blur had similar degradative effects on crowded and isolated visual acuity (P > 0.05), whereas eccentric viewing resulted in a larger deterioration of visual acuity for crowded tests (E2 of 0.86-1.06) than for isolated optotypes (E2 of 1.57-1.72) (P < 0.05). Maximum crowding effects occurred for closer target-flanker separations than those currently used commercially.CONCLUSIONS: In so far as blur and eccentric viewing mimic spatial acuity deficits in amblyopia, the results suggest that crowded tests might be of limited value in the detection of anisometropic amblyopia, but should be valuable in the detection of strabismic amblyopia. Crowding effects would be greater if flanking features were placed closer to the target than they currently are in commercially available charts.
KW - amblyopia
KW - children's visual acuity charts
KW - crowding
KW - dioptric blur
KW - eccentric viewing
UR - http://www.scopus.com/inward/record.url?scp=84925559170&partnerID=8YFLogxK
U2 - 10.1167/iovs.13-12543
DO - 10.1167/iovs.13-12543
M3 - Article
C2 - 24071956
AN - SCOPUS:84925559170
VL - 54
SP - 6934
EP - 6943
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 10
ER -