Abstract
Purpose :
The aim of this study was to assess the thickness of the ganglion cell-inner plexiform layer complex (GC-IPL) in autosomal dominant optic atrophy (ADOA) and its nasotemporal thickness profile in relation to healthy individuals.
Methods :
The study included 145 participants (74 males, 71 females, mean age 44, SD ± 20 years) with various OPA1 mutations, 63 of their first-degree relatives (24 males, 39 females, mean age 38, SD ± 18 years) and 92 unrelated healthy controls (40 males, 52 females, mean age 42, SD ± 19 years). Retinal structure was assessed using optical coherence tomography (OCT) with automated layer segmentation, ETDRS grid pattern thickness analysis (Heidelberg Spectralis, Heidelberg, Germany) and comparison of thickness profiles between groups (RStudio, mixed model, corrected for age and sex with family and eye as a random effect).
Results :
For ADOA subjects, first-degree relatives and unrelated controls, mean GC-IPL thickness 3 mm nasal of the foveal center was 43, 98 and 95 µm respectively, whereas 3 mm temporal of the foveal center it was 44, 93 and 89 µm, showing that on a cohort level the nasotemporal thickness ratio is inverted in ADOA, namely 0.98, compared to 1.05 and 1.07 in subjects without ADOA (p<0.001). The thickness 6 mm nasal of the fovea center in the three respective groups was 43, 68 and 67 µm and 6 mm temporal of the fovea and 45, 70 and 66 µm, showing that a difference in pattern of ratio reversal was absent at this eccentricity (p=0.8 for ADOA versus first-degree relatives). More than half the participants with ADOA had nasotemporal GC-IPL thickness ratios lower than 1.0, which was found in less than 5 % of unrelated healthy subjects.
Conclusions :
Half the participants with ADOA in this study were immediately recognizable in that their perifoveal GC-IPL layer was thicker on the temporal than on the nasal side of the fovea, which did only occur in few unrelated healthy controls and relatives without OPA1 mutations. Recognizing this characteristic will often make it possible to make a spot diagnosis of ADOA by comparing the nasal and temporal perifoveal ETDRS field thicknesses.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.