Abstract
Purpose:
Intravitreal ranibizumab (IVTR RBZ) has been used to treat wet age-related macular degeneration (AMD) in the UK since 2007. Aflibercept (AFL) was approved in Scotland in 2013 as an alternative anti-vascular endothelial growth factor (anti-VEGF) agent. We wanted to evaluate the effect on our patients who had previously been treated with RBZ of switching treatment to AFL.
Methods:
We collected data on 208 patients, previously treated with RBZ, who were switched to AFL at the Princess Alexandra Eye Pavilion in Edinburgh between September 2013 and May 2014. Data was collected using case notes and optical coherence tomography (OCT) images. Data included best-corrected logMAR visual acuity (BCVA), central macular thickness (CMT) measurements, duration of treatment and number of previous RBZ injections. Paired t-test were used to compare BCVA and CMT results achieved with RBZ and AFL.
Results:
The BCVA and CMT improved significantly following 3 RBZ loading injections, with a mean gain of 4.06 ETDRS letters (p <0.0001) and a decrease of 68μm in CMT (p<0.0001). At switch both the BCVA and CMT had significantly deteriorated with disease progression compared to the post-RBZ loading results with a mean loss of 6.6 letters (p< 0.0001) and increase of CMT of 29μm (p<0.0001). Following AFL treatment, the BCVA reduced by 0.6 EDTRS letters from switch but this was not significant. The mean CMT showed a significant reduction of 58μm (p< 0.0001). At switch, patients had received an average of 12 RBZ injections and 12 outpatient review appointments over a mean treatment period of 125 weeks. In patients who gained >10 letters the time from diagnosis to switch was 102 weeks and in those who lost >15 letters it was 138 weeks.
Conclusions:
Our data shows that in those patients who continue to have active disease with RBZ treatment, following initial gains achieved after loading doses, vision is lost at the rate of 3.1 letters per year. Following a switch to AFL this rate of vision loss is reduced to 1.42 letters per year and OCT CMT is reduced by a mean of 58μm. Therefore AFL appears to be effective at slowing the rate of vision loss and increase drying of the macula. AFL demonstrates the potential to further reduce blindness rates from wet AMD and the data suggests an earlier switch to AFL is advisable.