Evaluating the efficacy of subthreshold micropulse laser combined with anti-VEGF drugs in the treatment of diabetic macular edema: a systematic review and meta-analysis.

OBJECTIVE: To compare the clinical efficacy of subthreshold micropulse laser (SML) combined with anti-VEGF drugs versus anti-VEGF drugs monotherapy for diabetic macular edema (DME) through a meta-analysis. METHODS: We systematically reviewed relevant literature from electronic databases and extracted key outcomes, including best corrected visual acuity (BCVA)-comprising ETDRS and LogMAR measures, central macular thickness (CMT), annual frequency of anti-VEGF injections, annual SML applications, and associated complications for both treatment groups at postoperative intervals of 3, 6, 9, and 12 months. RESULTS: A total of 13 relevant studies were included in this review, including 405 eyes in the experimental group (SML combined with anti-VEGF drugs intravitreal injections) and 400 eyes in the control group (anti-VEGF drugs monotherapy). The results showed no significant difference in ETDRS visual acuity between the two groups at any time point (P > 0.05). However, LogMAR visual acuity significantly improved in the experimental group compared to controls at both 6 and 12 months post-treatment (P < 0.05). Subgroup analysis based on baseline CMT values indicated that patients with baseline CMT < 400 µm had significantly more reduced CMT across all observation points in the experimental group (P < 0.05). Conversely, no significant differences in CMT were found among those with baseline CMT ≥ 400 µm (P > 0.05). Additionally, annual intravitreal injection frequency of anti-VEGF drugs was significantly reduced in the experimental group compared to the controls (P < 0.05). The average numbers of SML applications per year ranged from 1.41 ± 0.37 to 3.4 ± 1.4 times (range: 1-4 times). Common postoperative complications included mild subconjunctival hemorrhage, a light ocular inflammatory reaction, and/or ocular surface discomfort. CONCLUSION: Compared to anti-VEGF drugs monotherapy, combining SML with anti-VEGF drugs can improve visual acuity and reduce macular edema among DME patients-especially those with central macular thickness < 400 µm. The combined approach also reduces anti-VEGF drugs intravitreal injection frequency, and repeated use of SML can alleviate economic burdens on patients. SYSTEMATIC REVIEW REGISTRATION: https://inplasy.com, identifier INPLASY2024120068.