An Automated Comparative Analysis of the Exudative Biomarkers in Neovascular Age-Related Macular Degeneration, The RAP Study: Report 6

Abstract

PurposeTo explore the differences in volume and distribution of exudative biomarkers across macular neovascularization (MNV) types and subtypes using artificial intelligence (AI). DesignCross-sectional study. MethodsWe applied an AI-based analysis of 34.528 OCT b-scans of 281 (250 unifocal, 31 multifocal) MNV3, 55 MNV2, and 121 (30 polypoidal, 91 non-polypoidal) MNV1 treatment-naïve eyes. We compared the means (standard deviations) and heat maps of cystic intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachments (PED) and hyperreflective foci (HRF) volumes, as well as retinal thickness (RT) among MNV (sub)types. ResultsMNV3 had the highest mean of IRF with 291 (290)nl, RT with 357 (49)µm, and HRF with 80 (70)nl, p≤0.05. MNV1 showed the greatest mean of SRF with 492 (586)nl, MNV3 the lowest with 218 (382)nl, p≤0.05. Heat maps showed IRF confined to the center while SRF scattered in all types. SRF, HRF and PED were more distributed in the temporal macular half in MNV3. Means of IRF, HRF and PED were higher in multifocal than in unifocal MNV3 with 416 (309)nl,114 (95)nl, and 810 (850)nl, p<0.05. Compared to the non-polypoidal subtype, the polypoidal subtype had greater means of SRF with 695 (718)nl, HRF 69 (63)nl, RT 357 (45)µm and PED 1115 (1170)nl, p<0.05. ConclusionThis novel quantitative AI analysis showed that SRF is a biomarker of choroidal origin in MNV1, whereas IRF, HRF and RT are rather biomarkers of retinal origin in MNV3. Polypoidal MNV1 and multifocal MNV3 present with higher exudation compared to other subtypes.