Long-term Assessment of Longitudinal Multi-Layer Retinal Dynamics in Non-neovascular Age-Related Macular Degeneration: Comparative Assessment of Eyes Progressing to Advanced Disease

Abstract

Purpose : This study evaluates the longitudinal retinal and sub-retinal pigment epithelium (RPE) dynamics on spectral domain optical coherence tomography (SD-OCT) in non-neovascular age-related macular degeneration (AMD) to compare eyes converting to advanced disease [e.g., subfoveal geographic atrophy (sfGA), neovascular AMD (nAMD)] and those without conversion.

Methods : This was a retrospective cohort study of eyes with non-neovascular AMD without sfGA with macular cube SD-OCT scans available at baseline, year 3, and year 5. Based on disease status at year five, eyes were categorized into one of three subgroups: non-conversion, sfGA converter, or nAMD converter. The macular cube scans at baseline and year three were evaluated using an automated machine learning-enhanced multi-layer segmentation platform with expert reader verification for assessment of retinal anatomy, including assessment of outer retinal integrity [e.g., ellipsoid zone (EZ)] and the sub-RPE compartment (e.g., drusen burden). Multiple metrics were generated and compared using paired t-tests and two-sample t-tests, as appropriate.

Results : Fifty-three eyes were included in this analysis. Measures of EZ integrity showed progressive loss in all 3 groups. Mean EZ-RPE central subfield volume (CSV) significantly decreased from baseline to year 3 in non-converters (0.29 ± 0.005mm³ vs. 0.024 ± 0.0067mm³, p<0.002), sfGA convertors (0.017±0.0064mm³ vs. 0.0096±0.0068mm³, p<0.03), and nAMD convertors (0.25 ± 0.006mm³ vs. 0.018 ± 0.0091mm³, p<0.0007). Mean sub-RPE compartment CSV increased in the non-converters (0.024±0.0099mm³ vs. 0.029±0.015mm³, p<0.03), decreased in the sfGA converters (0.042±0.019mm³ vs. 0.020±0.015mm³) and was unchanged in the nAMD converters (0.029±0.013mm³ vs. 0.032±0.017mm³, p=0.45). Increased sub-RPE compartment macular volume (p<0.005) and decreased macular retinal volume (p<0.04) over 3 years was associated with conversion to advanced disease.

Conclusions : Targeted assessment of regions of interest identify longitudinal changes in drusen burden and outer retinal integrity in eyes with non-neovascular AMD over a 5-year period. Specific anatomic features, such as sub-RPE compartment characteristics, should be further explored as potential biomarkers for progression risk.

This is a 2020 ARVO Annual Meeting abstract.