Strategies Needed to Improve Visual Acuity for Diabetic Macular Edema

July 28, 2020

Patients demonstrate visual gains from baseline but mean visual acuity worsens between 2 and 5 years.

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.