Abstract
Purpose :
The progression rates for functional loss (visual acuity, VA) and structural change (fundus autofluorescence, AF) in Stargardt patients appear to vary by the degree of loss at presentation. Amongst participants of the Progstar study, we evaluated the progression rates in patients who were recently symptomatic, defined as presenting within 2 years of reported symptom onset.
Methods :
36 participants (71 eyes) of the 251 participants enrolled in the retrospective study had onset of symptoms within 2 years of their first visit, and had at least one visit with both VA and AF reported. Among them, 65 eyes had ≥2 visits with both VA and AF. VA was reported as best corrected/presenting acuity and converted to LogMAR. Atrophic lesions identified from AF images were graded using a standard protocol, and areas of decreased AF were reported as follows: Definitely decreased AF (DDAF), poorly-demarcated questionably decreased AF, and well–demarcated questionably decreased AF. We used linear models with generalized estimating equations to compare baseline VA and lesion areas, and linear mixed effects models to estimate the yearly progression rate of VA and lesion areas.
Results :
The median age at first visit was 21 years (range, 7 to 63), and 78% were within one year of symptom onset. At the first visit, median LogMAR VA was 0.70 (IQR 0.3-0.9). The median DDAF area was 0, (IQR 0-0.12), and the mean area in the 32% of eyes with DDAF was 1.85mm2. The mean total area of decreased AF was 1.51mm2 (SD=1.88). The median duration of follow-up was 3 years (IQR 2-4 years). In longitudinal analysis, the loss of VA was 0.05 LogMAR (95%CI 0.04-0.07) per year, and a greater rate of VA loss was associated with better initial VA (p<.0001). The yearly progression rate for total area of decreased AF was 0.50 (95%CI: 0.40-0.60)mm2. The yearly progression rate for DDAF was 0.38 (95%CI: 0.27-0.50) mm2. An increase in both DDAF and total lesion area was associated with a loss of VA (p<.001).
Conclusions :
This cohort of Stargardt participants who reported onset of symptoms within two years had highly variable visual acuity and lesion area, with slow progression per year. Increase in lesion area over time was associated with loss of VA.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.