Abstract
Purpose :
To determine the effect of switching to aflibercept intravitreal injection in the treatment of neovascular age related macular degeneration (AMD), in eyes previously responded or not responding to ranibizumab.
Methods :
This is a prospective study evaluating the clinical outcomes of switching from ranibizumab to aflibercept in treatment resistant neovascular AMD at a district general hospital, United Kingdom.
Patients are selected from routine AMD clinics. Primary outcome is the change in best-corrected visual acuity evaluated using the Early Treatment Diabetic Retinopathy Study (EDTRS) chart. Secondary outcome is the change of central retinal thickness (CRT, μm) on optical coherence tomography scans and the average number of ranibizumab injections received prior to the switch.
Exclusion criteria are patients have previously received bevacizumab injections, photodynamic therapy, not completing the initial loading dose regimen of anti-vascular endothelial growth factor (VEGF) injections and missing data.
Results :
Twenty-six eyes have been identified, to date 14 of which have completed the 12 month follow up after switching to aflibercept.
Average VA prior to switching was 46.8 EDTRS letters. At 3, 6 and 12 months after the switch, average VA was 47.4 (standard error of mean (SEM), 3.6; p>0.05), 49.2 (SEM, 2.6; p>0.05) and 49.4 (SEM, 2.5; p>0.05) letters respectively.
Three months after the switch, 9 eyes (64%) had gained more letters, with an average letter gain of 0.6; at 12 months, 12 eyes (86%) had a better VA and the average letters gain was 2.6.
Mean CRT prior to aflibercept was 264.6 μm. Post-switch at 3, 6 and 12 months were 251 μm (SEM, 17.1; p>0.05), 267.1 μm (SEM, 26.6; p>0.05) and 254.1 (SEM, 13.8; p>0.05) respectively.
At 12 months after receiving aflibercept, 7 patients (50%) had a reduction in CRT and there was an average of CRT reduction of 10.5 μm.
Before the switch, the average number of ranibizumab injection received was 12.6.
Conclusions :
Our prospective study has shown that switching from ranibizumab to aflibercept in persistent neovascular AMD improved the VA at 12 months in majority of patients, with some anatomical improvements on OCT scans. The small sample size limited the statistical power. We are continuing our study with a bigger sample size to investigate further the effect of aflibercept switch in patients with persistent neovascular AMD.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.