Effect of dexamethasone implant between vitrectomized and non-vitrectomized eyes with diabetic macular edema

Abstract

Abstract Background To compare the 3-month foveal thickness, sub-foveal choroidal thickness (SFCT) change and best-corrected visual acuity (BCVA) LogMAR response after a sustained release dexamethasone (DEX) intravitreal implant (Ozurdex®) between non-vitrectomized and vitrectomized eyes with diabetic macular edema (DME). Methods Retrospective, comparative, and consecutive review of the medical records of 66 patients with decreased visual acuity, due to refractory DME, who underwent a single and the first injection of Ozurdex® between May 2016 and December 2020 at the teaching hospital of Kaohsiung Medical University. Then, patients were divided into 2 groups: 41 eyes who had undergone standard pars plana vitrectomy (vitrectomized group), and 25 eyes that were not operated on (non-vitrectomized group). Measured outcomes were the change of BCVA LogMAR, foveal thickness, and SFCT from baseline to months 1, 2 and 3. Results Forty-one of 66 eyes had prior vitrectomy (62%). Statistically significant improvement in foveal thickness and SFCT was seen at 1, 2 and 3 months with respect to baseline data, after treatment with a DEX implant in either group (P < 0.0001). There was statistically significant difference in SFCT between non-vitrectomized and vitrectomized eyes at month 3 and the trend from baseline to month 3 (P < 0.0001). Conclusion In this study, the clinical findings were similar between non-vitrectomized and vitrectomized eyes. Intravitreal treatment with an Ozurdex® implant safely reduced DME both in foveal and SFCT in both groups. However, there was statistically significant difference in the trend of SFCT between non-vitrectomized and vitrectomized eyes from baseline to month 3. A DEX implant could be cleared more rapidly in vitrectomized eyes by early detection from SFCT change.