Effects of Dexamethasone Implant on Multifocal Electroretinography in Central Retinal Vein Occlusion

Purpose To investigate the effect of Ozurdex (dexamethasone intravitreal implant) on multifocal electroretinography (mfERG) findings during the treatment of macular edema secondary to the central retinal vein occlusion (CRVO). Methods Fifteen eyes of 15 patients who were treated with Ozurdex implant due to CRVO-related macular edema were included in this study. Best corrected visual acuity (BCVA), central macular thickness (CMT), and mfERG evaluations were performed for all patients before injection of Ozurdex. After the injection, BCVA and CMT were measured at months 3 and 6 and mfERG test was performed at month 6 for all patients. Results Pre-implantation mfERG P wave amplitude values of r1, r2, r3, r4 and r5 were 57.8 ± 14.8, 25.1 ± 10.6, 17.2 ± 7.3, 12.0 ± 5.0 and 7.1 ± 3.6 nV/deg2, respectively. They increased to 72.9 ± 33.2, 31.2 ± 9.3, 22.6 ± 7.6, 15.6 ± 7.1 and 10.9 ± 5.7 nV/deg2, respectively, at month 6. However, these increases were not statistically significant (all P > 0.05). Pre-implantation mfERG r1, r2, r3, r4 and r5 P wave implicit times were 40.1 ± 10.9, 39.4 ± 3, 38.4 ± 3.4, 38.2 ± 3.1 and 39.3 ± 2.2 ms, respectively and these values were measured as 38.9 ± 8.2, 38.4 ± 4.7, 37 ± 3.8, 37.5 ± 4.6 and 37.7 ± 4.7 ms at 6 months. Although there were reductions in P wave implicit times in all rings, they were not statistically significant (all P > 0.05). Conclusion In this prospective study, we found that the Ozurdex implant had no effect on mfERG findings 6 months after insertion for treatment of CRVO-related macular edema.