Thickness mapping of individual retinal layers and sectors by Spectralis SD‐OCT in Autosomal Dominant Optic Atrophy

Abstract

PurposeTo assess layer‐ and location‐specific retinal thickness deficits in autosomal dominant optic atrophy (ADOA) on Spectralis SD‐OCT.MethodsThis cross‐sectional study included 41 ADOA patients with OPA1 exon 28 (2826delT) mutation (age, 8.6‐83.5 years; best‐corrected visual acuity (BCVA), 8‐89 ETDRS letters) and 55 mutation‐free first‐degree healthy control relatives (age, 8.9‐68.7 years; BCVA, 80‐99 ETRDS letters). Participants underwent routine examination and OCT with thickness analysis of the total retina, inner retinal layers and outer retinal layers. Individual segmentation was performed of the perifoveal retinal nervefiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer, outer plexiform layer, outer nuclear layer and peripapillary RNFL. Segmentation lines were moved manually to fit optimally with the borders between the layers. Combinations of layers and sectors were tested for their diagnostic significance. Statistical analysis was corrected for age, gender, spherical equivalent, axial length and family clustering in a mixed model analysis.ResultsThe perifoveal RNFL, GCL, IPL and the peripapillary RNFL were all significantly thinner in ADOA patients than in healthy controls (p < 0.0001). No statistical difference was found for other layers. The largest deficit was found in the GCL (‐49.9%), and it reached its maximum in the “nasal inner macula” sector with a thickness deficit of ‐63%. Attenuation of the peripapillary RNFL was most prominent temporally to the optic disc (‐58.4%).ConclusionsIn ADOA, retinal ganglion cells are most prominently missing in the nasal perifoveal area of the GCL, which together with the temporal peripapillary RNFL area serves as the strongest diagnostic OCT marker of ADOA.