Abstract
Purpose :
Patients with diabetic macular edema (DME) may demonstrate poor anatomical and visual improvements despite intensive intravitreal bevacizumab injections. We performed a prospective, open-label clinical trial to evaluate the efficacy of switching therapy from bevacizumab to aflibercept in patients with treatment resistant DME.
Methods :
Patients with DME and a central macular thickness (CMT) >300µm on spectral domain optical coherence tomography (SD-OCT) despite at least 4 treatments in the prior 6 months with intravitreal bevacizumab were recruited for this trial. Those with poor diabetic control, defined as a glycosylated haemoglobin (HbA1C) >12%, were excluded. All participants were reviewed every 4 weeks up to 48 weeks. Five initial loading doses of 2mg of intravitreal aflibercept were administered every 4-weeks until week 20, at which point the treatment interval was extended to 8-weeks until week 48. At every visit, ophthalmic examinations included best-corrected visual acuity (BCVA) measured with Early Treatment of Diabetic Retinopathy Study charts and CMT measured with SD-OCT. Primary outcomes were changes in CMT and BCVA at week 48 compared to baseline.
Results :
A total of 22 eyes from 22 patients who have completed 48 weeks of follow-up were included in this analysis. Baseline mean ± standard deviation (SD) age of these patients was 63.8±10.7 years, duration of diabetes was 16.7±10.3 years and HbA1C was 7.8±1.7%.. Prior to enrolment, study eyes had 21.6±11.3 intravitreal anti-VEGF injections over a period of 33.6±25.7 months. Mean CMT reduced from 415±108µm at baseline to 348±100µm at 48-weeks (67µm reduction, p=0.03). Mean BCVA improved from 67.8±10.4 letters at baseline to 71.0±10.6 letters at 48-weeks (3.2 letter gain, p=0.02). CMT decreased with each successive loading dose until the treatment interval was extended to 8 weeks, at which point an oscillating pattern was observed. BCVA was not affected in this manner and visual gains were maintained despite extension of the treatment interval.
Conclusions :
Intravitreal aflibercept was effective in improving anatomical and visual outcomes among these patients poorly responsive to intravitreal bevacizumab with 12 months of follow up.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.