Relative ellipsoid zone reflectivity and its association with disease severity in age-related macular degeneration: a MACUSTAR study report

Abstract

Quantification of the relative ellipsoid zone reflectivity (rEZR) might be a structural surrogate parameter for an early disease progression in the context of age-related macular degeneration (AMD). Within the European multicenter, cross-sectional MACUSTAR study, we have devised an automatic approach to determine the mean rEZR [arbitrary units, AU] at two independent visits in SD-OCT volume scans in study participants. Linear mixed-effects models were applied to analyze the association of AMD stage and AMD associated high-risk features including presence of pigmentary abnormalities, reticular pseudodrusen (RPD), volume of the retinal-pigment-epithelial–drusenoid-complex (RPEDC) with the rEZR. Intra-class correlation coefficients (ICC) were determined for rEZR reliability analysis. Within the overall study cohort (301 participants), we could observe decreased rEZR values (coefficient estimate ± standard error) of − 8.05 ± 2.44 AU (p = 0.0011) in the intermediate and of − 22.35 ± 3.28 AU (p < 0.0001) in the late AMD group. RPD presence was significantly associated with the rEZR in iAMD eyes (− 6.49 ± 3.14 AU; p = 0.0403), while there was a good ICC of 0.846 (95% confidence interval: 0.809; 0.876) in the overall study cohort. This study showed an association of rEZR with increasing disease severity and the presence of iAMD high-risk features. Further studies are necessary to evaluate the rEZR’s value as a novel biomarker for AMD and disease progression.

Transducin-Deficient Rod Photoreceptors Evaluated With Optical Coherence Tomography and Oxygen Consumption Rate Energy Biomarkers

“…Clinically, the intensity of OCT ISez band at its maximum value measured from patients is an accepted biomarker of photoreceptor health whose relative reflectance is linked with outer retina neurodegenerative disease severity and degeneration. 26 , 28 , 87 , 91 – 94 On the other hand, the relevance of a single value of ISez intensity measured with OCT in relation to mitochondria is unclear, and comparing single intensity measurement between subjects remain challenging in practice because of issues such as a lack of a consensus method for performing intensity normalization. 26 , 28 , 87 , 91 – 94 …”

“… 26 , 28 , 87 , 91 – 94 On the other hand, the relevance of a single value of ISez intensity measured with OCT in relation to mitochondria is unclear, and comparing single intensity measurement between subjects remain challenging in practice because of issues such as a lack of a consensus method for performing intensity normalization. 26 , 28 , 87 , 91 – 94 …”

Imaging Modalities for Dry Macular Degeneration

“…72,73 Large SDD is also associated with reduced reflectivity of the EZ in iAMD. 74,75 In eyes with GA, areas with disrupted EZ produce a larger scotoma than areas with an intact EZ. 76 Taken together, the EZ may serve as a marker for functionality.…”

“…Using a multifocal electroretinogram, reduction and recovery in intensity on OCT can be measured as an abnormal and normal response, respectively 72,73 . Large SDD is also associated with reduced reflectivity of the EZ in iAMD 74,75 . In eyes with GA, areas with disrupted EZ produce a larger scotoma than areas with an intact EZ 76 .…”