Vitrectomy in Diabetic Macular Edema:: A Swept-source OCT Angiography Study

PURPOSE: The foveal avascular zone (FAZ) has been reported to decrease after anti-VEGF injections in diabetic macular edema (DME) in the long term. This study aimed to present the changes in swept-source OCT angiography after vitrectomy in patients with DME. DESIGN: Retrospective interventional study. PARTICIPANTS: Thirty-five eyes were included (mean age: 62 years). METHODS: Patients were followed for 12 months after vitrectomy with internal limiting membrane peeling for DME. MAIN OUTCOME MEASURES: The following parameters were measured: central retinal thickness (CRT), central choroidal thickness, superficial FAZ, deep FAZ (dFAZ), and vessel density in the superficial and deep retinal layers (dVD). RESULTS: The CRT and superficial FAZ significantly decreased after surgery (401 μm–338 μm; P < 0.00, 401 μm–293 μm; P < 0.001, respectively). Initial visual acuity (VA) improved from 20/160 (0.97 logarithm of the minimum angle of resolution [LogMAR]) to 20/80 (0.62 LogMAR) (P < 0.001). The vessel density in the superficial retinal layers rate was 42.3% and decreased after surgery, reaching 41.6% at the end of the follow-up. The dVD rate 1 week after surgery was 28.9% and remained stable throughout the observation period. The most important prognostic factors for the final VA were preoperative VA and preoperative CRT, while the dFAZ and dVD at the time of edema resolution also correlated with the final VA. CONCLUSIONS: The superficial FAZ decreases after vitrectomy, which might indicate that vitrectomy has a protective effect on DME, similar to anti-VEGF injections. Prognostic factors for better final functional results are better initial VA and lower CRT before vitrectomy, in addition to a lower dFAZ diameter and a higher dVD at the moment of edema resolution. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.