Choroidal biomarkers to predict long term remission and poor response with standardized anti-vascular endothelial growth factor regimen

Abstract

Purpose : To determine the role of choroidal biomarkers to predict treatment response in neovascular age related macular degeneration(nAMD).

Methods : : A retrospective review of patients with nAMD being treated at a tertiary institute were followed up from presentation to last visit with a minimum follow up of eighteen months. Individuals on long term treatment with inability to extend medication beyond a month without a relapse and needing double the dose of medication(n=25) were labelled poor responders (PR). Individuals who went into long term remission after atleast three injections and remained dry for more than a year until the last visit(n=20) were included in the group of good responders(GR). Multimodal imaging [including fluorescein angiogram(FA) and optic coherence tomogram(OCT)] and comprehensive ocular evaluation were done at each visit. Choroidal vascularity index was calculated as a percentage of luminal area upon total choroidal area using image J. The retinal and choroidal differences on OCT between the two groups were then statistically analysed at presentation and last visit both intra and intergroup.

Results : The good responders showed a statistically significant reduction between the first and last visit in their central retinal thickness(p=0.0001), subfoveal choroidal thickness(p=0.005), choriocapillaris thickness(p=0.0001) and choroidal vascularity index(p=0.02). The poor responders showed a statistically significant difference in the CRT(p=0.002), SFCT(p=0.0007), CC(p=0.0001), Haller’s and Sattler’s layers(p=0.03) and the CVI(p=0.001).The results showing the differences between good and poor responders are tabulated in Table 1.

Conclusions : SFCT was a good predictor of response to anti VEGF treatment, response being inversely proportional to the SFCT. Initial change in CVI after three injections was an additional predictor for long term stabilization of the disease. CC thickness responds significantly to anti-VEGF post three injections in both the groups suggesting a possible site of action for the anti-VEGF drugs.

This is a 2020 ARVO Annual Meeting abstract.