What This Means
This research suggests that intravitreal injections of conbercept, an anti-VEGF drug, can meaningfully improve vision and retinal health in people with diabetic macular edema (DME), a common diabetes complication that can cause vision loss due to fluid buildup in the central part of the retina. The study followed 119 patients for two years, all of whom received five monthly injections to start. After that, half were treated with a 'pro re nata' (PRN) approach — meaning injections were given only when signs of disease activity returned at monitoring visits — while the other half followed a 'treat-and-extend' (T&E) strategy, where treatment intervals were gradually lengthened based on how well each patient was responding. Both approaches produced similar improvements in vision, retinal thickness, blood vessel health, and other measures of disease, with these gains appearing as early as six months into treatment and holding through the full two years.
The key practical difference between the two strategies was in the burden they placed on patients and the healthcare system. Patients in the T&E group received an average of about 11.4 injections over two years compared to about 14 injections in the PRN group, and they needed roughly 14 clinic visits compared to nearly 25 visits for PRN patients. This research suggests that the T&E approach can achieve the same level of disease control with fewer injections and far fewer clinic visits, which could meaningfully reduce time, cost, and inconvenience for patients.
One notable finding was that some measures — particularly those related to blood vessels, hard deposits (hard exudates), and bleeding in the retina — took longer to improve than basic vision and retinal thickness measures, with some not showing significant change until 18 or even 24 months of follow-up. This highlights that the full benefits of anti-VEGF treatment for DME may take considerable time to become apparent, and sustained treatment may be necessary to achieve improvements across all aspects of the disease.