Switching to subtenon triamcinolone acetonide does not jeopardize the functional and anatomic outcomes of dexamethasone implant treated eyes with diabetic macular edema

Intraocular dexamethasone implant (DEXi) is an efficient treatment for diabetic macular edema (DME). However, it may be unavailable or contraindicated. Triamcinolone acetonide is another corticosteroid that has proved to be safe and effective in treating macular edema complicating various diseases including diabetes. The purpose of this study is to evaluate the outcomes of a switch from DEXi to subtenon triamcinolone acetonide (STTA) and back, in eyes with DME. Retrospective study. DME eyes that had been treated with DEXi and switched to STTA between October 2018 and February 2019 (stock shortage of DEXi) were included. The functional and anatomical outcomes of the switch and switch-back were studied. 26 eyes of 17 patients (mean age 67.1 ± 8.2 years) were considered. The mean baseline visual acuity (VA) was 0.35 ± 0.17 decimals remaining stable after DEXi, STTA and switch-back to DEXi. The mean central macular thickness (CMT) was 492.7 ± 32.8 µm initially, decreasing to 294.3 ± 133.4 µm after DEXi, 369.9 ± 182.3 µm after STTA and 297.6 ± 72.0 µm after switching back to DEXi (all p < 0.05 versus baseline). Compared to baseline, the CMT reduction was numerically better after DEXi and switching back to DEXi than after STTA (mean reduction: -200.4 µm, -167.7 µm, and -95.08 µm respectively, p = 0.13). Intraocular pressure was comparable after DEXi and STTA. DEXi is the steroid of choice in DME. However, STTA can be a cost-effective alternative when DEXi is unavailable or contraindicated. This study suggests that STTA may be used in the context of a step therapy in DME.