Abstract
Purpose :
Reticular pseudodrusen (RPD) in age-related macular degeneration (AMD) have been reported to be associated with retinal thinning. Recent improvements in Heidelberg Spectralis imaging software allows better segmentation and analysis of retinal layers in pathology. This study was performed to compare the total and segmented retinal layer volumes of RPD and non RPD patients using the updated software.
Methods :
In this retrospective study, non-neovascular AMD patients with and without RPD were identified from the retinal imaging report database of Jacobs Retina Centre, Shiley Eye Institute, UCSD. Retinal layer segmentations were performed using Heidelberg Engineering software (HEE, Germany, Version 1.10.4.0). The total and segmented volumes of the ETDRS zone and the total volumes of the constituent outer ring, inner ring and fovea, from SD-OCT volume scans were analyzed. All patients with a history of retinal surgery, concurrent macular disorders, active retinal vascular diseases and myopia (> -2.00 D) were excluded from the study.
Results :
Forty six RPD eyes from thirty three patients and thirty seven non-RPD eyes from twenty nine patients were included in the study. Patients in the two groups (RPD and non RPD) were age and sex matched. The volumes of each ring of ETDRS zone- outer, inner and fovea, as well as the volumes of inner nuclear layer (INL) and outer nuclear layer (ONL) of RPD patients were significantly lower than the respective values for non-RPD patients . RPD patients’ RPE volume was significantly higher than that of non-RPD patients’.
Conclusions :
RPD represents subretinal deposits that extend through the outer nuclear layer, affect photoreceptor integrity and are associated with RPE disruption. In our cohort, the segmented neuroretinal volume suggests that the inner and outer nuclear layers, in particular, are significantly thinner in RPD patients compared to non RPD patients. This greatly expands our knowledge on the RPD AMD phenotype by specifically identifying the layers which lead to retinal thinning using the updated segmentation softwares. Also, the total retinal volume was found to be signficiantly lower in RPD patients compared with non-RPD patients lending support to views suggesting retinal thinning in RPD patients. The RPE layer thickness was higher in RPD patients compared to non RPD patients suggesting sub-RPE thickening.
This is a 2020 ARVO Annual Meeting abstract.