Inflammatory phenotype associated with high risk MMP9 genotype in neovascular AMD

Abstract

Purpose : MMP9 is expressed in choroidal dendritic cells (DCs) and the MMP9 locus has been associated with neovascular AMD (nvAMD). We evaluated the potential association of systemic inflammatory markers with visual acuity, injection burden, and fluid parameters derived from AI based quantitative OCT analysis of nvAMD patients with high-risk MMP9 genotype.

Methods : An ensemble approach of U-Net architectures (convolutional neural networks) developed for retinal pathology segmentation, was trained to simultaneously segment intraretinal (IRF), subretinal fluid (SRF), and pigment epithelial detachment (PED) regions from Heidelberg OCT scans in nvAMD subjects (n=100) receiving consecutive anti-VEGF injections (comprising 6320 OCTs obtained from 2009-2022). 10-fold cross-validation was performed with training OCT scans from 90 subjects and a validation dataset of 10 subjects. We compared segmented regions for patients with either high or low-risk MMP9 genotypes.

We utilized optimized spectral flow cytometry panels using Cytek Aurora to assess the steady-state phenotype (31-colors) and effector functions (23-colors) of human T cells from PBMCs in 10 nvAMD subjects previously genotyped for MMP9. Using our 31-color steady-state panel, we determined the subset distributions of the main T cell populations (e.g., naïve, memory, etc.) in these subjects.

Results : 10-fold cross-validation yielded high R² of 0.85, 0.95, and 0.89 for predicted vs ground truth of OCT quantified IRF, SRF, and PED volumes, respectively.

Flow cytometry showed that patients with high-risk MMP9 genotype have CD4 T cells with a trend (p=0.051) toward greater capacity to generate IL-4 and IL-13, both of which are major contributors to fibrosis. There was a moderate correlation of worse VA with increased % CD4 Temra cells (r=0.66; p=0.037) and % CD8 Tscm of CD8 T cells (r=0.68; p=0.030). %CD4 Temra T cells showed a positive association with IRF volume (p=0.013) and PED volume (p=0.001).

Conclusions : An ensemble approach of AI-based image analysis has been validated for accurate fluid segmentation techniques in nvAMD. Patients with worse visual acuity and fluid may be experiencing higher systemic levels of inflammation. Patients with high risk MMP9 genotype may be skewed to a Th2 phenotype that could be associated with dysregulated wound healing in nvAMD.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.