Strategies Needed to Improve Visual Acuity for Diabetic Macular Edema

Dante Pieramici, MD

The findings of research presented at the American Society of Retina Specialists (ASRS 2020) Virtual Sessions suggest methods to improving long-term visual outcomes in eyes with diabetic macular edema are needed.

Dante Pieramici, MD, and colleagues assessed treatment patterns and long-term outcomes in eyes with center-involved diabetic macular edema that had treatment with anti-vascular endothelial growth factor therapy. The investigators had participants of Protocol T return for a five-year visit 3 years after the trial ended. The two-year multicenter clinical trial compared aflibercept, bevacizumab, and ranibizumab anti-vascular endothelial growth factor (anti-VEGF) treatments for diabetic macular edema in eyes with baseline visual acuity of 20/32 to 20/320.

The team assessed routine clinical care practices for participants. They retrospectively collected data on clinical visits and retina treatments in the study eye occurring between the two- and five-year extension period. Further, Pieramici and the investigators reported on five-year outcomes of visual acuity and central subfield thickness change from baseline and 2 years.

At the five-year visit, ocular and medical histories were obtained, along with visual acuity, eye exam, optical coherence tomography, and color photos.

The primary objective for the 3 years after Protocol T was stopped was to provide information on treatment course, visual acuity, and diabetic macular edema. The main objective did not include comparing treatment groups after 2 years, Pieramici said during the presentation of his research team’s data and findings.

Of the 463 eligible participants, 68% completed a five-year visit. Over the three years, the median number of visits with a retina specialist was 12 years (IQR, 5-21_. The median number of anti-VEGF injections was 4 (IQR, 0-12), with 68% receiving at least 1 injection.

At 5 years, visual acuity was an average of +7.4 letters (95% CI, +5.9 to +9) higher than baseline visual acuity but -4.7 letters (95% CI, -3.3 to -6) lower than two-year visual acuity. For patients with baseline visual acuity 20/50 to 20/320, the mean visual acuity at 5 years was +11.9 letters (95% CI, +9.3 to +14.5) higher than baseline but -4.8 letters (95% CI, -2.5 to -7) lower than 2 years.

Among patients with baseline visual acuity 20/32 to 20/40, mean visual acuity at 5 years was +3.2 letters (95% CI, +1.4 to +5) higher than baseline but -4.6 letters (95% CI, -3.1 to -6.1) lower than 2 years. Central subfield thickness at year 5 was an average -154µm (95% CI, -142 to -166) thinner than baseline and showed no substantial changes (-1µm; 95% CI, -12 to +9) from CST at 2 years.

“On average, patients demonstrated visual gains from baseline, but mean visual acuity worsened between 2 and 5 years,” Pieramici said.

Still, additional strategies to improve long-term visual outcomes in clinical care among eyes with diabetic macular edema are needed, he concluded.

The study, “Five-Year Outcomes After Initial Aflibercept, Bevacizumab, or Ranibizumab Treatment for Diabetic Macular Edema (Protocol T),” was presented at ASRS 2020.