Laser Treatment for Diabetic Retinopathy: History, Mechanism, and Novel Technologies

Background: Diabetic retinopathy (DR), as a complication of diabetes mellitus (DM), remains a significant contributor to preventable vision impairment in the working-age population. Laser photocoagulation is essential in treating DR in conjunction with anti-vascular endothelial growth factor (VEGF) injection, steroids, and vitrectomy. This review summarizes the history of laser photocoagulation and highlights its current role and long-term effectiveness in real-world conditions. Methods: The National Clinical Trial (NCT), PubMed, Google Scholar, and China National Knowledge Infrastructure (CNKI) databases were searched utilizing combined or individual keywords, and a total of 121 articles were reviewed by the authors. Results: Several novel laser photocoagulation technologies, such as patterned scanning laser, subthreshold micropulse laser, navigated laser, multimodal imaging-guided laser, and retina rejuvenation therapy, substantially decrease the adverse effects and improve the accuracy and security of laser therapy. Numerous studies have demonstrated the outstanding clinical efficacy of combination therapies with pharmacologic treatments like anti-VEGF in treating DR and diabetic macular edema (DME). A 20-year follow-up retrospective study in our center preliminarily demonstrated the long-term effectiveness of conventional laser photocoagulation. Conclusions: More clinical trials are required to confirm the clinical effectiveness of novel laser technologies. Better treatment protocols for the combination therapy may be detailed. Anti-VEGF treatment has better effects, especially for DME and in a short period. But in real-world conditions, given the long-term effectiveness and economic advantages of conventional laser treatment, it should be prioritized over anti-VEGF injection in certain situations.