Abstract
Purpose :
Achromatopsia (ACHM) is an autosomal recessive disease that results in reduced or absent cone function. There is controversy regarding the extent to which cone structure shows progressive degeneration in ACHM. Here we performed a retrospective review of optical coherence tomography (OCT) images to evaluate cone structure over time in patients with genetically confirmed ACHM.
Methods :
Sixty-three patients with ACHM (due to CNGA3, CNGB3, or ATF6 mutations) with Bioptigen or Cirrus OCT images from multiple time points stored in the Advanced Ocular Imaging Program Bank were included. Integrity of the ellipsoid zone (EZ) was assessed twice by a single grader (GG) in a masked fashion using the grading scale from Sundaram et al (2014).1 Images with disparate grades between the two assessments were finalized by a second grader (JC).
Results :
A total of 457 OCT images were processed and graded, 236 OD and 221 OS. The baseline distribution of EZ grades was highly symmetrical between eyes (OD: I=8, II=33, III=2, IV=17, V=3; OS: I=8, II=32, III=2, IV=17, V=2). The average patient age was 23.01 years at the first visit and 25.99 at the last visit, with an average time between visits of 2.88 years for OD images and 2.56 years for OS images (range from 5 months to 10 years). A total of five eyes showed change in EZ grade (OD: n=3, OS: n=2) across follow-up from a grade II (EZ disruption) to grade IV (hyporeflective zone). These eyes belonged to three individuals (aged 24, 29, & 35 years), representing 4.76% of the total study group. The remaining 60 subjects, 95.24% of the total study group, retained the same EZ grade throughout the follow-up period.
Conclusions :
ACHM appears to be a generally stable condition, at least over the follow-up period assessed here. Even with stable EZ appearance there may be other factors that impact the therapeutic potential of a given ACHM retina, which may change/progress over time.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.