Relationship Between Drusen Height and OCT Biomarkers of Atrophy in Non-Neovascular AMD

Abstract

Purpose To determine if increasing drusen height correlates with predictive optical coherence tomography (OCT) biomarkers of atrophy. Methods Retrospective cross-sectional study that enrolled patients with drusen associated with intermediate AMD. Macular drusen were classified as small, intermediate, large, or very large based on OCT quartile measurement of height. Drusen diameter was also tabulated. The presence and localization of the OCT biomarkers of atrophy were assessed: disruption of the external limiting membrane and ellipsoid zone, intraretinal hyper-reflective foci, RPE disruption, choroidal hypertransmission, and presence of hyporeflective cores. Predictive OCT biomarkers of atrophy were correlated with drusen height. Results A total of 155 eyes from 104 patients met the inclusion and exclusion criteria. The mean age was 75.7 ± 8.7 years, and patients were predominantly female (74.0%). The mean visual acuity was logMAR 0.2 ± 0.2 (Snellen equivalent 20/32). The average drusen height was 134.6 ± 107.5 µm and the greatest horizontal diameter was 970.7 ± 867.4 µm. Disruption of the external limiting membrane and ellipsoid zone, RPE thickening or thinning, intraretinal hyper-reflective foci, choroidal hypertransmission, and presence of hyporeflective cores ( P < 0.05) were more common in eyes with large drusen and very large drusen versus small or intermediate drusen. All biomarkers were positively correlated with drusen height. OCT biomarkers of atrophy were predominantly located at the apex of the drusen. Conclusions Predictive OCT biomarkers of atrophy, specifically signs of RPE breakdown and disruption, occur more commonly in large or very large drusen, especially in drusen with greater height and separation of the RPE from the underlying choroid.

From drusen to type 3 macular neovascularization

“…8 The mean height of the precursor druse/dPED in our study was 105.3 6 34.2 mm with a range of 52 mm to 197.5 mm. The height was greater than 107 mm in a total of eight eyes (40%) in our study, which is consistent with large or very large drusen based on the classification of Au et al 12 Quantitative measurements and qualitative OCT evaluation of the drusen at different time points before the onset of T3 MNV.…”

“…The location of the T3 MNV over the apex versus the slope of the drusen was analyzed as previously described. 12 The apex was defined as the peak or apical third. Either side of the apex on the downslope of the drusen was defined as the slope.…”

Pathways of Fluid Leakage in Age-Related Macular Degeneration

“…This may explain why taller drusen are more likely to display biomarkers of RPE atrophy, such as intraretinal hyperreflective foci and plumes, especially at the apex, and why larger drusen are at a greater risk of collapse and atrophy. 22 In fact, the presence of nonneovascular SRF associated with large drusen may be a marker for the development of iRORA (incomplete RORA) and cRORA. Hilely et al 10 noted that more than 50% of cases of drusen associated with SRF proceed to iR-ORA or cRORA.…”

Pushing Retinal Imaging Forward: Innovations and Their Clinical Meaning – The 2022 Ophthalmologica Lecture

“…Of note, biomarkers can be either prognostic or predictive: while prognostic biomarkers represent clinical or biological characteristics providing information on patients' outcomes regardless of the treatment [61], a predictive biomarker may indicate the potential benefit from treatment for a specific patient, as compared to the baseline condition [61]. Several prognostic and predictive OCT biomarkers have been described as structural qualitative or quantitative features associated with different retinal disorders [62][63][64][65][66][67][68][69][70][71].…”

“…This may eventually result in the PED's collapse and consequent RPE atrophy. Greater RPE displacement from the inner choroid may increase the risk of RPE ischemia and atrophy, especially at the apex [66].…”