Abstract
Purpose:
To assess retinal and Bruchs membrane/retinal pigment epithelial complex morphology in patients switched from ranibizumab to aflibercept in nAMD.
Methods:
Systematic evaluation of patients (n=20) with nAMD deemed as non responders to ranibizumab and switched to aflibercept between May 2013 and Sept 2013. We measured best corrected visual acuity (BCVA), performed high resolution optical coherence tomography, fluorescein angiography (FA) and indocyanine green angiography (ICG) prior to initiating a new loading phase with aflibercept 2.0mg. FA and ICG were examined for the presence of mature choroidal vessels, retinal angiomatous proliferation, polypoidal choroidopathy with or without a branching vascular network (BVN). Tomograms were graded for retinal pigment epithelial detachment (PED), integrity of the RPE and the external limiting membrane (ELM). The height of subretinal fluid (SRF), retinal thickness (RT), PED and choroidal thickness (CT) were recorded.
Results:
The majority of eyes (n=10) demonstrated a BVN with or without visible polyps or a mature vessel complex (n=9). Mean BCVA (ETDRS letters) at treatment initiation with ranibizumab was 67.3 ±13.3 and at switch to aflibercept was 59.5 ±10.9. BCVA at 1 month post switch was 63.2±15.2. Following the switch, intraretinal fluid (IRF) and intraretinal cysts (IRC) reduced in 80% and 70% of treated eyes respectively and restoration of the ELM was seen in one third. Reductions in RT from 318±115 µM to 263±67 µM, PED height from 303±174 µM to 230±118 µM, SRF from 82±79 µM to 38±43µM were observed but only SRF was statistically significant (p < 0.005). CT did not change significantly pre switch 188±20 µM to post switch 174±16 µM.
Conclusions:
Non responders to ranibizumab when switched to aflibercept showed morphological changes by Month 1 suggesting a degree of normalization of the RPE photoreceptor interface with reductions in retinal thickness.
Keywords: 412 age-related macular degeneration •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
748 vascular endothelial growth factor