Investigators reported improvements in BCVA and in central subfield thickness, but noted decreases in superficial and deep capillary density.
Cyrus Golshani, MD
With diabetic macular edema being the most common cause of vision loss among people with diabetic eye disease, treatment of the disease is a hot topic among ophthalmologists.
A recent study, presented at the 2019 Annual Meeting of the Association of Research in Vision and Ophthalmology, found that patients who switched from other anti-vascular endothelial growth factor (anti-VEGF) agents to intravitreal aflibercept saw significant anatomic improvements in central subfield thickness (CST) and improvements in visual acuity.
Investigators from the Cleveland Clinic Cole Eye Institute presented their 12-month analysis of their SNAP-TWO study. The purpose of the study was to report the outcomes of 20 eyes with DME after transitioning from either ranibizumab or bevacizumab to intravitreal aflibercept. Investigators only examined one eye in each patient to better compare results.
Cyrus Golshani, MD, lead author and fellow at the Cleveland Clinic, told MD Magazine investigators noted an apparent lack of well-designed, clinical trials that have evaluated the effect of switching anti-VEGF agents on DME outcomes. The purpose of this study was the evaluate 12-month outcomes of these aforementioned patients.
The trial’s primary outcome was a mean absolute change from baseline CST at 12-months measured by OCT. Secondary outcomes included mean change from baseline in the early treatment diabetic retinopathy study (ETDRS) visual acuity, anatomic parameters, and OCT angiography (OCTA) capillary perfusion density (CPD) in the superficial and deep capillary layers after transition to IAI therapy.
Investigators examined one eye, regardless of whether the other eye had DME, in 20 participants who had been undergoing treatment with ranibizumab or bevacizumab. All patients received 2 mg (0.05 mL) of intravitreal aflibercept every 4 weeks until optical coherence tomography (OCT) demonstrated no evidence of fluid, which investigators defined as CST of less than 320 µm, extrafoveal cystoid macular edema (CME), or foveal CME with foveal depression present or with fovea flat. Subsequently, patients receiving a fixed dosing schedule of 2 mg of intravitreal aflibercept once every 8 weeks through 24 months with a planned interim analysis at 12 months.
At baseline, BCVA was 69.95 letters, mean CST was 419.7 µm +/-92.0, superficial CPD was 46.0% +/-4.2, and deep CPD was 50.8% +/-4.3. Investigators found that, in the study eye, mean visual acuity had improved to 71.5 at 6 months and to 74 at 12 months, mean CST on OCT improved to 287.2 µm +/-80.2, superficial CPD decreased to 43.6%+/-4.8, and deep CPD decreased to 47.6% +/-4.8.
Golshani added that he was not surprised by most of the results from the trial, but that he had not been expecting a drop in CPD. He noted that the drop was not associated with any significant changes in vision.
“So, the central subfield thickness decreased, which was not surprising but what was interesting in this was even though vision got better, the fluid went down. The OCT analysis, the superficial and deep capillary perfusion decreased where you would expect it to increase,” Golshani said. “Some studies say as you improve your swelling with DME the superficial vascular density should increase, others say it should decrease. That was a little surprising.”
This poster, titled “Diabetic Macular Edema Treated with Intravitreal Aflibercept Injection After Treatment with Other Anti-VEGF Agents (SWAP-TWO Study) — 12-month interim analysis,” was presented at the 2019 Annual Meeting of the Association of Research in Vision and Ophthalmology.