Intravitreal Aflibercept for Treatment-Resistant Diabetic Macular Edema: 3-month findings

Abstract

Purpose: To assess the efficacy of switching to intravitreal aflibercept in patients with diabetic macular edema (DME) resistant to treatment with other anti-vascular endothelial growth factor (anti-VEGF) agents.

Methods: Twenty one participants with treatment-resistant DME were enrolled in a prospective, open-label trial of 5 loading injections of aflibercept 4 weeks apart followed by injections every 8 weeks. Inclusion and exclusion criteria included: persistent DME despite at least 4 anti-VEGF injections within 6 months, central macular thickness (CMT) ≥300µm and haemoglobin A1C (HbA1C) ≤12% at baseline. Participants underwent full ophthalmic examinations at each visit including; best-corrected visual acuity (BCVA) in early treatment in diabetic retinopathy study (ETDRS) letters and spectral-domain optical coherence tomography (SD-OCT) to measure CMT. Changes in mean BCVA and CMT were compared between baseline and week 12 using paired t tests. Pearson’s correlation was used to assess the correlation between a change in BCVA and a change in CMT.

Results: At baseline, mean HbA1C was 7.4 ± 1.1%. Mean baseline BCVA and CMT was 69.0 ± 10.3 letters and 408.7 ± 111.5 µm respectively. After 3 loading injections, mean BCVA improved by 3.2 ± 7.2 letters (p=0.06) compared to baseline, with 42.9% of participants improving by ≥5 letters by week 12. Compared to baseline, mean CMT improved by 35.5 ± 69.3 µm (p=0.03) at week 12, with 38.1% of participants improving by ≥50 µm by week 12. A change in BCVA was not correlated with a change in CMT after 12 weeks (r²=-0.31, p>0.05).

Conclusions: Intravitreal aflibercept shows early effectiveness in improving vision and reducing CMT in previously treatment-resistant DME over 12 weeks. Longer follow-up is required to determine the response of a complete loading dose and the sustainability of improvements.