The Progression of Stargardt Disease Using Volumetric Hill of Vision Analyses Over 24 Months: ProgStar Report No.15

Am J Ophthalmol. 2021 Oct:230:123-133. doi: 10.1016/j.ajo.2021.04.015. Epub 2021 May 2.

Abstract

Purpose: To report the yearly rate of change in macular function in patients with Stargardt disease type 1 (STGD1) over 24 months and to establish a new volumetric visual function index for use in clinical trials investigating the efficacy on retinal sensitivity.

Methods: Design: International, multicenter, prospective cohort study with 5 study visits every 6 months over 24 months.

Participants: A total of 233 individuals with genetically confirmed STGD1 (≥1 disease-causing ABCA4 variant).

Main outcome measures: The total volume (VTOT) beneath the sensitivity surface of a 3-D model of the hill of vision and mean sensitivity (MS) derived from mesopic microperimetry performed with a white stimulus. Changes of VTOT over time and its correlation with the ABCA4 genotype and baseline features.

Results: At baseline, 440 eyes (233 patients) with a mean (SD) age of 33.7 (15.0) years, mean (SD) visual acuity of 46.08 (16.03) ETDRS letters were analyzed with an average VTOT of 0.91 decibel-steradian (dB-sr) and an MS of 10.73 dB. The overall mean rate of decrease in sensitivity [95% confidence interval] was 0.077 [0.064, 0.090] dB-sr/y for VTOT and 0.87 [0.72, 1.02] dB/year for MS. The progression rate of VTOT depended on baseline visual function (0.029 dB-sr/year for low and 0.120 dB-sr/year for high baseline VTOT; P < .001) and exhibited a difference in the first vs second year of follow-up (0.065 dB-sr/year vs 0.089 dB-sr/year, respectively; P < .001). The absence of pigmentary abnormalities of the retinal pigment epithelium at baseline was found to be associated with a faster progression rate (P < .001), whereas a significant association with the genotype was not detected (P = .7).

Conclusion: In STGD1, both microperimetric outcomes demonstrate statistically significant and clinically meaningful changes after relatively short follow-up periods. Volumetric modeling may be useful in future interventional clinical trials that aim to improve retinal sensitivity or to slow down its decline and for structure-function correlations.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • Adult
  • Disease Progression
  • Humans
  • Prospective Studies
  • Retina* / diagnostic imaging
  • Stargardt Disease
  • Tomography, Optical Coherence
  • Visual Acuity
  • Visual Field Tests
  • Visual Fields*

Substances

  • ABCA4 protein, human
  • ATP-Binding Cassette Transporters