Abstract
Purpose :
Late-onset retinal degeneration (L-ORD) is a monogenic, autosomal dominant retinal disease involving C1QTNF5 which is expressed in the RPE. We investigate whether quantitative analysis of longitudinal multimodal imaging can characterize disease progression.
Methods :
Fundus autofluorescence (FAF) and infrared reflectance (IR) fundus imaging of 4 L-ORD patients were acquired over 3–15 years. FAF and IR images were spatially registered in time and across modalities using automatic custom algorithms. Characteristic regions of interest were manually contoured. Reticular pseudodrusen (FAF RPD), abnormal FAF, and geographic atrophy (GA) were contoured on FAF, and hyporeflective RPD and target RPD were contoured on IR. Computed quantitative measurements included contour area, distance to fovea, and percentage of contour overlap.
Results :
Over time, the contoured region of GA monotonically encroaches towards the fovea and increases in area over time (n= 6 eyes). The distance to the fovea of abnormal FAF contours also decreases monotonically over time (n=8 eyes). Within a single visit, contoured RPD areas in FAF (FAF RPD) overlap with contoured areas in IR of both target and hyporeflective RPD (8 eyes, 40 visits). Regions with newly evolved GA were analyzed at previous timepoints to quantify the percentage that was previously abnormal FAF or FAF RPD. One year prior to GA development, 92% (± 7%) of the corresponding regions have abnormal FAF and 6% (± 6%) have FAF RPD. Six years prior to GA, the regions consist of 61% (± 27%) abnormal FAF and 27% (± 23%) FAF RPD. Ten years prior to GA, the regions consist of 34% (± 11%) abnormal FAF and 44% (± 11%) FAF RPD. Similarly, one year prior to the appearance of new regions of abnormal FAF, 68% (± 40%) are occupied by FAF RPD, which decreases monotonically at more remote timepoints.
Conclusions :
Even at timepoints prior to the development of GA, image analysis reveals consistent patterns over time and space revealing progression from FAF RPD to abnormal FAF to GA. Quantifying the progressive changes in time and space in L-ORD may provide useful outcomes for L-ORD and other degenerative retinal diseases.
This is a 2020 ARVO Annual Meeting abstract.