Posterior vitreous detachment rate following intravitreal dexamethasone injection

To determine whether intravitreal dexamethasone (DEX) implant induces posterior vitreous detachment or not.

We retrospectively reviewed 810 eyes of 405 patients who underwent intravitreal DEX implantation due to macular edema caused by diabetic and retinal venous occlusion in our clinic. The eyes having no injection were determined as the control group. The examination findings of the patients before the injection and 3mo after the injection and optical coherence tomography (OCT) images were scanned. The pre-injection OCT findings and OCT findings of the patients having no posterior vitreous detachment (PVD) and determined to have partial PVD were compared.

The separation in vitreoretinal adhesion and total PVD development of DEX-injected 56/208 (26.9%) eyes were statistically greater in comparison with the 12/129 (9.3%) eyes that had not been injected (P=0.001). PVD development was observed more in the patients that were younger, had larger macula thickness and lower visual acuity.

It can be stated that intravitreal DEX implant induces PVD development. Prospective, controlled studies are required in order to determine prognosis of vitreoretinal disease in PVD-developed patients and in non-PVD-developed patients.