Early Retinal and Choroidal Coat Thickness Changes after Intravitreal Dexamethasone Implant Injection for Diabetic...

Intravitreal steroid injection is one of the treatment options for diabetic macular edema. Dexamethasone implant is the most novel form of intravitreal steroid therapy. Improvement in macular thickness is a well-known effect of Dexamethasone implant however, subfoveal choroidal coat thickness changes require investigation.

To evaluate the early central macular thickness and subfoveal choroidal thickness alterations after single-dose dexamethasone implant injection in diabetic macular edema.

Cross-sectional study.

We identified 29 patients with diabetic macular edema (29 eyes) who underwent optical coherence tomography and fundus fluorescein angiography. All patients received a single-dose intravitreal Dexamethasone implant and were followed up for central macular thickness and subfoveal choroidal thickness alterations for 1 hour, 1 week, 1 month, and 3 months post-injection.

The preoperative mean central macular thickness and subfoveal choroidal thickness measurements were 592.3±122.3 (412–879) μm and 264.8±53.7 (165–397) μm, respectively. Central macular thickness measurements decreased significantly in the first hour (p<0.050) and continued to decrease until the third month (p<0.001), whereas the subfoveal choroidal thickness decrement was only significant on the first day (p<0.05). Decreases in subfoveal choroidal thickness and central macular thickness of 1.5% and 5% were observed at 1 hour; however, the difference was not significant (p>0.050). The decrease in central macular thickness was significantly greater than that in subfoveal choroidal thickness at 1 day, 1 week, 1 month, and 3 months (p<0.001).

Intravitreal Dexamethasone implant has a meaningful effect on central macular thickness in patients with diabetic macular edema, while subfoveal choroidal thickness decreases significantly at first day.