Clinical real-world data evaluation: comparison of central macular thickness after anti-VEGF treatment in diabetic macular edema patients treated with or without topical anti-glaucoma agents

There are research findings suggesting that antiglaucoma agents may reduce aqueous humor outflow and decrease the elimination of intravitreally administered anti-vascular endothelial growth factor agents, prolonging their effect. The aim of this study was to evaluate central macular thickness (CMT) after repeated injections, using real-world data, to provide insight into how this phenomenon may affect clinical outcomes. One hundred forty-seven patients with diabetic macular edema (DME) were included in the study;66 patients received topical therapy due to pre-existing glaucoma, either primary open- angle or pseudoexfoliative glaucoma, and 81 patients without glaucoma. CMT values were evaluated before treatment, 1 month after the first three injections, 1 month after the subsequent four injections, and at the end of the first year. No significant differences were detected with respect to HbA1c levels, the presence of SRF, or prior photocoagulation (p = 0.085, p = 0.24, and p = 0.3, respectively). There was no difference between anti-glaucoma agent users and control group in CMT measurements 1 month after the first three injections (p = 0.6, p > 0.05). However, measurements taken 1 month after the subsequent four injections were significantly lower in patients using topical anti-glaucoma agents (p = 0.001, p < 0.05). At the 1-year measurement interval, although the values remained lower, the significant difference had disappeared (p = 0.11, p > 0.05). The presence of hyper reflective dots (HRD) was also greater in this group (p = 0.021, p < 0.05). At the 1-year measurement interval, although the values remained lower, the significant difference had disappeared (p = 0.11, p > 0.05). The presence of HRD and the combined presence of SRF and HRD had a significant effect on the changes in the measurements (F (4.412), p = 0.006, Eta2 = 0.103 and F (4.51), p = 0.001, Eta2 = 0.106, respectively). Although the use of topical anti-glaucoma therapy may have a partial effect on reduction of CMT in DME patients receiving anti-vascular endothelial growth factor (anti-VEGF) treatment.