Positive impact on visual outcomes through reduction of macular thickness fluctuations with 0.19-mg fluocinolone acetonide implant

Purpose: Retinal thickness fluctuations (RTF) have been associated with best-corrected visual acuity (BCVA). The current study aimed to assess the effectiveness of 0.19-mg fluocinolone acetonide intravitreal (FAc) implant to control RTF and its effect on BCVA. Methods: The RIVER study was a multicenter, retrospective, and non-interventional study that analyzed the data of the Retina.pt Portuguese national registry. Retinal thickness was assessed using the spectral domain optical coherence tomography (SD-OCT). The primary endpoint was the assessment of RTF. Eyes were stratified into quartiles (Q) and median-split according to their retinal thickness amplitude (RTA), retinal thickness standard deviation (RTSD), and central subfield thickness area under the curve (CST-AUC). Results: The mean RTA decreased from 187.6±150.4 µm at baseline to 151.6±126.4 µm after the Fac implant (at the last follow-up visit); p=0.1204. Mean RTSD significantly reduced from 96.3±78.1 µm at baseline to 60.8±57.3 µm at the last follow-up visit (p=0.0032). Compared to pre-FAc implant, BCVA significantly improved in eyes with RTA Q1, Q2, Q3; eyes with RTSD Q1, Q2, and Q3, and eyes with CST-AUC Q1, Q2, and Q3. According to the median split, eyes with RTA and RTSD < to median showed greater BCVA improvement. Conclusions: Regardless of the variable used to assess retinal thickness fluctuation, the FAc implant provided a significant reduction of its variability. Additionally, lower retinal thickness variability was associated with better visual outcomes.