Retinal Morpho-Functional Changes Following 0.19 mg Fluocinolone Acetonide Intravitreal Implant for Chronic Diabetic Macular Edema

PURPOSE: To evaluate morpho-functional outcomes of the intravitreal fluocinolone acetonide (FAc) implant. METHODS: Retrospective, observational, single-center study. Primary endpoint was the mean change in central macular thickness (CMT) from baseline to month 1–3. Secondary endpoints included mean CMT change from baseline to month 4–8 and 9–14 and mean best corrected visual acuity (BCVA), photopic negative response (PhNR) and b-wave of flash full-field electroretinogram (ERG) changes from baseline to month 1–3, 4–8, and 9–14. RESULTS: Fourteen patients (18 eyes) were included. Mean (standard deviation) CMT decreased from 473 (196) µm at baseline to 371 (163) µm at month 1–3 (mean difference − 102.3 ± 98.35 µm, 95% CI ± 46.4 µm; p < 0.0001) and this decrease tended to endure up to month 9–14. BCVA did not change significantly. There was an improvement in mean PhNR amplitude from 2.76 (1.65) µV at baseline to 3.73 (2.32) µV at month 1–3 (mean difference 0.91 (1.14) µV, 95% CI ± 0.54 µV, p = 0.003); b-wave amplitude improved from 8.83 (4.52) µV at baseline versus 10.05 (5.04) µV at month 1–3 (mean difference 1.22 (2.23) µV, 95% CI ± 1.08 µV, p = 0.0384). These ERG positive changes tended to endure up to month 9–14, although they did not reach statistical significance after month 3. CONCLUSIONS: Intravitreal FAc implant significantly improved anatomic as well as functional outcomes related to middle and inner retinal layers, known to be altered in diabetic retinopathy. Our findings support the hypothesis that intravitreal FAc implant may exert a protective effect in diabetic retinas with diabetic macular edema.