Novel Combination Therapy Shows Promise for Diabetic Macular Edema: Study
China: A new treatment approach for diabetic macular edema (DME), combining an initial intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection with a subsequent dexamethasone intravitreal implant, has demonstrated promising short-term outcomes. The strategy led to meaningful improvements in visual acuity and reductions in retinal swelling while requiring fewer injections, suggesting it could be an effective, less burdensome option for patients with DME.
The findings are from a study published in the journal Eye Discovery by Zhihui Dong, Department of Ophthalmology, The Third Affiliated Hospital of Wenzhou Medical University, Ruian City, Zhejiang Province, China, and colleagues.
Diabetic macular edema (DME) is a major cause of vision loss in people with diabetes. Standard treatment often requires repeated intravitreal anti-VEGF injections, which can impose substantial financial and treatment burdens. To evaluate a potentially less burdensome alternative, researchers compared a novel “1 + 1 + PRN” regimen with the conventional “3 + PRN” approach.
The retrospective study included 28 eyes from 23 treatment-naïve patients with DME. In the “1 + 1 + PRN” group, patients received one or two anti-VEGF injections followed by a dexamethasone intravitreal implant four weeks later, with additional anti-VEGF treatment given as needed. In the “3 + PRN” group, patients received three monthly anti-VEGF injections before switching to as-needed treatment.
The investigators assessed best-corrected visual acuity, intraocular pressure, and retinal imaging parameters at baseline and during follow-up visits extending to 25 weeks after treatment initiation.
The study led to the following findings:
- Both treatment regimens significantly improved best-corrected visual acuity and retinal anatomical parameters from baseline.
- Significant reductions were observed in central macular thickness, hyperreflective foci, and cyst area within the deep capillary plexus in both groups.
- No statistically significant differences were found between the two treatment strategies for visual or anatomical outcomes.
- The sequential anti-VEGF plus dexamethasone regimen showed a trend toward greater visual improvement, although the difference was not statistically significant.
- Central macular thickness decreased more steadily over time in the “1 + 1 + PRN” group, while mild fluctuations were observed in the conventional treatment group.
- Patients receiving the “1 + 1 + PRN” regimen required significantly fewer intravitreal injections than those treated with the standard “3 + PRN” protocol.
- Safety profiles were comparable between the two groups, with no significant difference in the incidence of elevated intraocular pressure.
The researchers noted several limitations, including the small sample size, retrospective design, short follow-up period, use of different anti-VEGF agents, and non-randomized treatment allocation, which may have introduced selection bias.
Despite its limitations, the study found that the “1 + 1 + PRN” regimen offered efficacy and safety comparable to the conventional approach, with potential benefits in visual outcomes, treatment stability, and reduced injection burden. Larger randomized studies are needed to confirm these findings.
Reference:
Dong, Z., Zhang, C., Dong, L., Zhang, J., Li, X., Yin, N., Xie, H., Wang, P., Lin, B., Zhang, F., Chen, Z., & Zhang, J. (2026). A short-term observational study: Initial intravitreal anti-VEGF injection followed by dexamethasone intravitreal implant for diabetic macular edema. Eye Discovery, 2(2), 100037. https://doi.org/10.1016/j.edisc.2026.100037
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