ANTI-VEGF TREATMENT

While the evidence from clinical studies supporting the therapeutic value of anti-VEGF agents for the treatment of diabetic macular oedema (DME) continues to mount, it seems patients in the real world are not receiving nearly the number of injections as patients in randomised clinical trials, nor are they experiencing the visual acuity improvement seen in those studies.

Speaking at the 2014 annual meeting of the American Society of Retinal Specialists in San Diego, USA, Nancy M Holekamp MD presented a “real-world” study indicating that patients receiving fewer anti-VEGF injections for DME have a corresponding lack of visual acuity improvement compared to what has been reported in randomised clinical trials.

“If you look at large electronic claims databases such as Medicare, it shows that patients with DME only receive between two and three anti-VEGF injection treatments in the first year of therapy. This is far below the monthly injections of ranibizumab seen in the RISE and RIDE trials, and is even less than the average of nine bevacizumab injections patients received in the BOLT study,” noted Dr Holekamp, Professor of Clinical Ophthalmology and Visual Sciences at the Washington University School of Medicine in St Louis, Missouri, USA.

She and her colleagues examined data from the Geisinger Health System to determine if fewer anti-VEGF injections resulted in less visual acuity improvement. Her study included all patients who had received anti-VEGF for DME for whom 12-month follow-up was available. Some 94 eyes with a mean visual acuity of 20/80 at baseline met the inclusion criteria.

At the 12-month mark the average number of injections was 2.6. Approximately 40 per cent of patients received only one injection, 19 per cent two injections, and 15 per cent three injections. Overall, 75 per cent of patients received three or fewer injections over the 12-month period.

At the six-month mark the researchers noted a mean increase in visual acuity of four letters, which fell to 3.7 at 12 months. By comparison, patients in the RISE and RIDE clinical trials gained more than 10 letters of visual acuity at month 12. According to Dr Holekamp, if one looks across all studies of anti-VEGF injections for DME, there is a linear association between the number of injections and the improvement in vision: the more injections, the better the vision.

“We already knew that patients in the real world were being undertreated. What this study shows for the first time is that they are also experiencing less visual acuity improvement. It may be hard to change this because the diabetic population has other health burdens. In patients with DME it may be useful to have treatments with longer duration of action, so patients can obtain better visual acuity improvement with fewer treatments,” she said.

Nancy M Holekamp: nholekamp@gmail.com