Efficacy of aflibercept in vitrectomized vs. non-vitrectomized eyes with diabetic macular edema: a prospective study

Diabetic macular edema (DME) is a leading cause of visual impairment in patients with diabetes. Intravitreal anti-vascular endothelial growth factor (VEGF) agents are the first-line treatment for DME, with aflibercept having demonstrated favorable outcomes in comparative studies. However, data on the efficacy of anti-VEGF therapy in vitrectomized eyes are inconclusive. Corticosteroids, specifically dexamethasone (DEX) implant, may be used for refractory cases. This study aimed to evaluate the efficacy of intravitreal aflibercept (IVA) in patients with DME with or without prior pars plana vitrectomy (PPV) and to evaluate the outcomes of DEX implantation in refractory cases.

This prospective single-center study included 46 eyes with center-involved DME. Eyes were divided into PPV and intact vitreous body (non-PPV) groups. All patients received IVA injections following the DRCR.net Protocol T. After six monthly injections, eyes refractory to IVA treatment were switched to DEX implant (refractory group). In the non-refractory group IVA injections were administered as needed (PRN) until month 12. The best-corrected visual acuity (BCVA) and central subfield thickness (CSFT) were measured at baseline; at 1 week; monthly through month 6 in all eyes; monthly through month 12 in the non-refractory group; and at 2 months after DEX implantation in the refractory group.

There were 23 eyes each in the PPV and non-PPV groups. Overall, 13 (28.3%) eyes were refractory to IVA (8 PPV, 5 non-PPV; p > 0.05). The median number of IVA injections among PPV and non-PPV eyes in the non-refractory group over 12 months showed no significant difference (PPV: 10; non-PPV: 9.5; p > 0.05). Both groups showed significant improvement in BCVA (PPV: +7.0 letters; non-PPV: +11.1 letters; both p < 0.01) and CSFT (PPV: - 182.5 μm; non-PPV: - 190.4 μm; both p < 0.01) at 12 months. In refractory cases, DEX implantation resulted in a significant CSFT reduction (-259.1 μm, p < 0.01) but not BCVA improvement.

IVA is effective for DME regardless of vitreous status, with similar efficacy and treatment frequency in vitrectomized and non-vitrectomized eyes. DEX implantation produces anatomical benefits in IVA-refractory cases, although visual gains are limited.