July 2020
Volume 61, Issue 9
Free
ARVO Imaging in the Eye Conference Abstract  |   July 2020
Spatial distribution of scotopic versus mesopic microperimetry detection thresholds in ABCA4-related Stargardt disease – the ProgStar-SMART study
Author Affiliations & Notes
  • Ahmed F Shakarchi
    Ophthalmology, Wilmer Eye Institute Johns Hopkins University, Baltimore, Maryland, United States
  • Xiangrong Kong
    Ophthalmology, Wilmer Eye Institute Johns Hopkins University, Baltimore, Maryland, United States
  • Footnotes
    Commercial Relationships   Ahmed Shakarchi, None; Xiangrong Kong, None
  • Footnotes
    Support  Supported by the Foundation Fighting Blindness Clinical Research Institute (FFB CRI) and a grant to FFB CRI by the U.S. Department of Defense USAMRMC TATRC, Fort Meade, Maryland (grant numbers W81-XWH-07-1-0720 and W81XWH-09-2-0189).
Investigative Ophthalmology & Visual Science July 2020, Vol.61, PB0059. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Ahmed F Shakarchi, Xiangrong Kong; Spatial distribution of scotopic versus mesopic microperimetry detection thresholds in ABCA4-related Stargardt disease – the ProgStar-SMART study. Invest. Ophthalmol. Vis. Sci. 2020;61(9):PB0059.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose : To assess the relationship between scotopic and mesopic functions using microperimetry detection thresholds spatially in the central retina in ABCA4-associated Stargardt Disease (STGD1).

Methods : Patients with ≥1 pathogenic ABCA4 mutation and a typical STGD phenotype were enrolled in 6 centers in the US and Europe. Study eyes had ≥1 area of atrophy on fundus imaging. One eye was chosen for both mesopic (MMP) and scotopic (SMP) microperimetry using the Nidek MP-1S device. For MMP, sensitivity was measured on a dim white background with a Goldmann III white stimulus at 68 loci covering the central 20°. The central 4 loci within 2° radius were excluded in this analysis. The max stimulus intensity was 2.1 log candela (cd)/m2. After MMP, the eye was dark adapted for 30 minutes, and SMP was tested at 40 loci in the parafovea (4-10° radially). The max illuminance was adjusted to 2.4 log scotopic cd (scd)/m2 via a blue filter and a 1.0-log ND filter (Fig1). MMP thresholds at the scotopic loci were predicted with simple kriging. Deming regression was run at each locus to model the mean of scotopic threshold as a linear function of mesopic thresholds accounting for random errors in both.

Results : The study enrolled 130 participants, median age 34 years, 53% female and 82% whites. In the superior field, the regression lines were flatter than inferiorly. The average of intercepts and slopes for superior loci were 0.35 and 1.23, and for inferior loci were -0.21 and 1.57. The average slope and intercept were 0.01 and 1.43 nasally, and 0.05 and 1.31 temporally (Fig2).

Conclusions : The positive intercept in the superior field implies that when mesopic function is within the normal range, the scotopic function is already showing decline. The slopes are greater than 1 across the field indicating that for impairment in mesopic function, the impairment in scotopic function is even greater. The impairment in scotopic function relative to that in mesopic function occurs faster in the inferior field. The relative impairment of rod and cone function is not uniform within the parafoveal central retina in STGD1.

This is a 2020 Imaging in the Eye Conference abstract.

 

Fig1. Microperimetry loci

Fig1. Microperimetry loci

 

Fig2. Deming regressions of scotopic vs mesopic detection thresholds. Intercept indicates scotopic threshold when mesopic threshold is 0 log(cd)/m2. Slope indicates change in scotopic threshold for 1 log(cd)/m2 change in mesopic threshold

Fig2. Deming regressions of scotopic vs mesopic detection thresholds. Intercept indicates scotopic threshold when mesopic threshold is 0 log(cd)/m2. Slope indicates change in scotopic threshold for 1 log(cd)/m2 change in mesopic threshold

×
×

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.

×