Efficacy of intravitreal dexamethasone implant in persistent diabetic macular edema after primary treatment with intravitreal ranibizumab

To evaluate the efficiency and possible complications of intravitreal dexamethasone (IVD) implant in diabetic macular edema (DME) resistant to treatment of three consecutive intravitreal ranibizumab (IVR) injections.

Fifty eyes of 38 patients were considered in this study. The best corrected visual acuity (BCVA), central macular thickness (CMT), and values of intraocular pressure (IOP) were examined preoperatively and postoperatively in the 1st, 2nd, 4th, and 6th months of IVD implantation.

Twenty of the patients were women, and 18 of the patients were men. Mean age was 64.63 ± 7.15 (52e83) years. Mean number of IVR injection before IVD implantation was 3.4 ± 0.38. Mean BCVA (logMAR) was 0.874 ± 0.398 before IVD implantation, 0.598 ± 0.306 at the 1st month, 0.602 ± 0.340 at the 2nd month, 0.708 ± 0.359 at 4th month, and 0.800 ± 0.370 at 6th month. Mean of CMT was 519.700 ± 155.802 mm before IVD implantation, 274.000 ± 73.112 mm at the 1st month, 307.98 ± 87.869 mm at the 2nd month, 387.82 ± 110.503 mm at 4th month, and 478.54 ± 163.743 mm at 6th month. Improvements in BCVA and CMT were statistically significant (P < 0.05) at 1st, 2nd, and 4th months; however, these values were not statistically significant at 6 months. At 1st day, 1st and 2nd months, the values of IOP were increased significantly after IVD. Cataract progression was observed in just 1 of the 22 phakic patients.

In DME resistant to treatment of consecutive IVR, IVD implantation has been observed to be effective in increasing BCVA and decreasing CMT in the first 3 months. IVD implantation can be considered an alternative method in the treatment of resistant DME.