title: Individual differences in the shape of the nasal visual field.
abstract: Between-subject differences in the shape of the nasal visual field were assessed for 103 volunteers 21-85years of age and free of visual disorder. Perimetry was conducted with a stimulus for which contrast sensitivity is minimally affected by peripheral defocus and decreased retinal illumination. One eye each was tested for 103 volunteers free of eye disease in a multi-center prospective longitudinal study. A peripheral deviation index was computed as the difference in log contrast sensitivity at outer (25-29° nasal) and inner (8° from fixation) locations. Values for this index ranged from 0.01 (outer sensitivity slightly greater than inner sensitivity) to -0.7 log unit (outer sensitivity much lower than inner sensitivity). Mean sensitivity for the inner locations was independent of the deviation index (R2<1%), while mean sensitivity for the outer locations was not (R2=38%, p<0.0005). Age was only modestly related to the index, with a decline by 0.017 log unit per decade (R2=10%). Test-retest data for 21 volunteers who completed 7-10 visits yielded standard deviations for the index from 0.04 to 0.17 log unit, with a mean of 0.09 log unit. Between-subject differences in peripheral deviation persisted over two years of longitudinal testing. Peripheral deviation indices were correlated with indices for three other perimetric stimuli used in a subset of 24 volunteers (R2from 20% to 49%). Between-subject variability in shape of the visual field raises concerns about current clinical visual field indices, and further studies are needed to develop improved indices.
authors.affiliation: Indiana University School of Optometry, 800 East Atwater Avenue, Bloomington, IN 47405-3680, United States. Electronic address: wilswans@indiana.edu.
authors.forename: William H
authors.initials: WH
authors.lastname: Swanson
authors.affiliation: SUNY College of Optometry, 33 West 42nd St, New York, NY 10036, United States. Electronic address: mdul@suny.edu.
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Dul
authors.affiliation: Indiana University School of Optometry, 800 East Atwater Avenue, Bloomington, IN 47405-3680, United States. Electronic address: hornerdg@indiana.edu.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Horner
authors.affiliation: Indiana University School of Optometry, 800 East Atwater Avenue, Bloomington, IN 47405-3680, United States. Electronic address: malinovs@indiana.edu.
authors.forename: Victor E
authors.initials: VE
authors.lastname: Malinovsky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011446:Prospective Studies; D012684:Sensory Thresholds / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult
keywords: Contrast sensitivity; Perimetry; Periphery; Visual field