June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Two-Color (Red-Blue) Dark Adaptometry: Sensitivity, Specificity and Clinical Application
Author Affiliations & Notes
  • Jeff C Rabin
    Optometry, UIW Rosenberg School of Optometry, San Antonio, Texas, United States
  • Brooke Houser
    Optometry, UIW Rosenberg School of Optometry, San Antonio, Texas, United States
  • Carolyn Talbert
    Optometry, UIW Rosenberg School of Optometry, San Antonio, Texas, United States
  • Ruh Patel
    Optometry, UIW Rosenberg School of Optometry, San Antonio, Texas, United States
  • Footnotes
    Commercial Relationships   Jeff Rabin, None; Brooke Houser, None; Carolyn Talbert, None; Ruh Patel, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 2482. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Jeff C Rabin, Brooke Houser, Carolyn Talbert, Ruh Patel; Two-Color (Red-Blue) Dark Adaptometry: Sensitivity, Specificity and Clinical Application. Invest. Ophthalmol. Vis. Sci. 2017;58(8):2482.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Dark adaptometry (DA) is a sensitive test for diagnosis of retinal disease including retinitis pigmentosa (RP) and macular degeneration. Patients requiring flash electroretinograms (ERGs) often benefit from DA for proper diagnosis. Our purpose was to develop a new DA test administered during the 20 min. dark adaptation period of the standard flash ERG (www.iscev.org) using alternating red and blue stimuli to bias the response in favor of cones (red) or rods (blue). We report sensitivity and specificity of this test.

Methods : An ERG Ganzfeld (Diagnosys, LLC) was used to measure DA in 21 normal subjects and 21 patients with retinal disease: RP/Ushers syndrome, cone dystrophy, Bests, fundus albipunctatus, DUSN, macular dystrophy, Allagile syndrome. Each subject initially underwent 75 sec. of pre-adaptation (1000 cd/m2) followed by 20 min. of DA during which the subject pressed a button each time she/he detected alternating 6 msec. flashes of red (630 nm) or blue (445 nm) light which diffusely illuminated the Ganzfeld. An adaptive staircase measured red and blue DA thresholds during DA. Final 20 min. and halfway (10 min.) red and blue thresholds were compared between groups.

Results : Mean (±2SD) red and blue DA was computed across normal subjects for 25 points in time during the 20 min. DA period yielding separate red and blue DA curves. Subjects were initially 1.5 log units (32x) more sensitive to blue vs. red light and 2.5 log units more sensitive to blue after 20 min. DA (p<0.0001) exemplifying greater sensitivity of rods to blue light. Both curves were flat at 15 min. indicating that absolute thresholds were achieved for parameters of this test. Combining 10 and 20 min. thresholds, 95% of patients were detected with DA (>2SD below normal); a patient with macular dystrophy was borderline normal. The most sensitive single parameter was blue DA at 10 min. (86% sensitivity) reflecting both delay and sensitivity loss. In RP (n=7) mean elevation in final blue threshold was 2.3 log units (200x).

Conclusions : Two-color (red-blue) DA offers high sensitivity (95%) for detecting dysfunction in various retinal diseases with 100% specificity in normals thus far. It is expediently measured during the DA phase of ERGs providing definitive separation of rod and cone function. The test shows promise for improving diagnosis and revealing functional impairment in vision debilitating disease.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×