ObjectiveTo evaluate the efficacy and safety of silicone oil removal combined with dexamethasone intravitreal implant (DEX) for the treatment of macular edema secondary to proliferative diabetic retinopathy (PDR). MethodsA retrospective case series study. From September 2023 to September 2024, 25 patients (25 eyes) with PDR complicated by macular edema who underwent silicone oil removal combined with DEX treatment at Eye Hospital of Shandong First Medical University were enrolled. There were 13 male patients (13 eyes) and 12 female patients (12 eyes). All eyes developed macular edema after pars plana vitrectomy (PPV) with silicone oil tamponade. All affected eyes underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examinations. BCVA was measured using the international standard logarithmic visual acuity chart, and the results were converted to logarithm of the minimum angle of resolution (logMAR) visual acuity records; OCT was used to measure the retinal thickness at the macular fovea (CMT). The surgical method was silicone oil removal combined with intravitreal injection of 0.7 mg DEX. At 1, 4, 8, and 12 weeks after the surgery, the above indicators were re-examined using the same methods and equipment as before the surgery. Paired t tests or Wilcoxon signed-rank tests were used to compare the changes in logMAR BCVA, CMT, and intraocular pressure before and after the surgery and between groups. ResultsThe logMAR BCVA values before surgery and at 4, 8, and 12 weeks after surgery were 1.12±0.11, 0.52 (0.30, 1.17), 0.30 (0.26, 0.50), 0.31 (0.30, 0.70). BCVA improved significantly after surgery, and the differences were statistically significant (t=3.492, 2.965, 4.739; P=0.003, 0.018, 0.001). The CMT values before surgery and at 1, 4, 8, and 12 weeks after surgery were (463.00±127.21), 245.66 (211.50, 305.23), (230.00±69.39), (240.59±48.75), and (251.56±69.86) μm. CMT decreased significantly after surgery, and the differences were statistically significant (t=?6.512, ?5.843, ?4.167, ?4.728; P＜0.05). One day after the surgery, two eyes developed transient elevation of intraocular pressure, which was controlled with topical hypotensive agents. During the follow-up period, no complications, such as migration of the implant into the anterior chamber, were observed. ConclusionsSilicone oil removal combined with DEX is effective and safe for the treatment of macular edema after PPV with silicone oil tamponade. It can significantly improve the patient's postoperative vision and effectively reduce macular edema.