The Efficacy and Safety of Subretinal Balanced Salt Solution Injection in Diabetic Macular Edema with Hard Exudates

Purpose: To evaluate the efficacy and safety of subretinal balanced salt solution (BSS) injection for diabetic macular edema (DME) patients with hard exudates (HEs) using a 40-gauge curved needle. Methods: DME patients with HEs were randomized to injection group (subretinal BSS injection combined with pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling, n = 28) or control group (PPV and ILM peeling, n = 28). Changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), HEs, foveal avascular zone (FAZ), and mean macular thickness (MMT) were compared. Patient demographics, laboratory results, and surgical complications were recorded and compared. Results: Baseline characteristics were similar ( P > 0.05). In the injection group, compared with the preoperative indicators, the postoperative BCVA (Snellen) improved from 20/426 ± 20/98 to 20/163 ± 20/59, CMT decreased from 453.32 ± 125.90 μm to 305.14 ± 119.23 μm, HEs area decreased from 3.00 ± 1.68 mm 2 to 1.50 ± 1.24 mm 2 , FAZ area decreased from 0.41 ± 0.11 mm 2 to 0.32 ± 0.11 mm 2 , MMT decreased from 411.77 ± 64.52 μm to 322.96 ± 52.62 μm ( P < 0.001, respectively). Postoperative BCVA, CMT, HEs area, FAZ, and MMT in the injection group were different from those in the control group ( P < 0.05). Postoperative complications did not differ (P > 0.05). The mean follow-up duration was 7.13 ± 2.02 months. Conclusion: Subretinal BSS injection with a 40-gauge curved needle is safe and effective for DME with HEs, improving macular structure and vision