Italy: Study on DEX and FAc Implants for Diabetic Macular Edema

A recent study reported that a positive response to the dexamethasone (DEX) implant may be predictive of positive responses to the fluocinolone acetonide (FAc) implant for diabetic macular edema (DME). The study was published in the Nature journal Eye on 21 January 2021.

Maria Vittoria Cicinelli, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy, and colleagues conducted the retrospective cohort study with an objective to determine if the visual and anatomic response to the first DEX implant predicts the 2-month clinical outcome after shifting to FAc implant in DME patients.

The study included pseudophakic patients with previously treated DME who underwent one or more DEX injections before FAc. Functional and morphologic response to DEX were defined based on the best-corrected visual acuity (BCVA) and central macular thickness (CMT) changes after the first DEX, respectively.

Steroid-response was defined as intraocular pressure (IOP) elevation ≥5 mmHg or IOP > 21 mmHg after any previous DEX exposure. The researchers performed pairwise comparisons for BCVA, CMT, and IOP after FAc with linear mixed models and a repeated-measure design. Forty-four eyes of 33 patients were included in the study.

Key Findings of the Study

• Patients were shifted to FAc after a mean ± standard deviation of 4.6 ± 3.2 DEX injections. Overall, BCVA and CMT improved during the first 12 months after switching to FAc.
• Only eyes with a good morphologic response to DEX had a significant CMT reduction after FAc, while no significant relationship was found between BCVA improvement after DEX and after FAc.
• IOP elevation occurred in 9 eyes (20%) following DEX implant.
• These eyes carried a 20-fold increased risk of having an IOP rise after FAc, with a non-linear relationship between the IOP increase after DEX and the one after FAc.

To conclude, response to previous DEX may anticipate the morphologic response to subsequent FAc. Those having steroid-induced IOP elevation in eyes after DEX were at high risk of IOP increase after FAc.

"The visual response after FAc was not related to the visual response to previous steroids, this indicates that FAc may have a role also in patients refractory to DEX implant," they concluded.

Reference

Cicinelli, M.V., Rosenblatt, A., Grosso, D. et al. The outcome of fluocinolone acetonide intravitreal implant is predicted by the response to dexamethasone implant in diabetic macular oedema. Eye 35, 3232–3242 (2021). https://doi.org/10.1038/s41433-020-01373-1