Author: João Leite (Portugal)
Co-authors: Catarina Castro, André Ferreira, João Coelho, Tânia Borges, Nuno Correia, Bernardete Pessoa
At present, spectral domain optical coherence tomography (SD-OCT) represents the main technique for assessment and follow-up of diabetic maculopathy (DM), once it offers both quantitative and qualitative information in a non-invasive and repeatable way. ESASO group proposed an SD-OCT-based classification of DM, centered on standard figures, which considers specific morphologic features and quantitative indices of the entire spectrum of macular involvement in diabetic retinopathy. ILUVIEN® intravitreal implant (fluocinolone acetonide, FAc 0.2 μg/day) is indicated for the treatment of persistent and recurrent Diabetic macular edema (DME) and it is known to release a sustained microdose of FAc 0.2 μg/day for up to 3 years. The aim of this study was to evaluate the long-term effectiveness of FAc implant as a treatment of recurrent and persistent DME based on OCT biomarkers assessment.
This is a retrospective analysis in which efficacy parameters as well as OCT biomarkers assessments of patients with persistent and recurrent DME treated with a single ILUVIEN® implant were analyzed, performed at Centro Hospitalar Universitário do Porto, Portugal.
Retrospective observational analysis, with 36 months follow-up after FAc implantation. The demographic data of the patients as well as duration of DME and number of prior intravitreal injections were recorded at baseline. Best Corrected Visual Acuity (BCVA) and central subfoveal thickness (CST) were recorded at baseline and then evaluated at month 6, 12, 24 and 36. All patients underwent OCT scanning before and after implantation of FAc, in all time-points. The characteristics of DME were analyzed in all OCTs, according to the classification for diabetic maculopathy proposed by ESASO, taking into account 7 parameters: (1) quantitative measurement of the CST; (2) the size of the intraretinal cysts (IRC); (3) the visibility of the external limiting membrane (ELM) and the ellipsoid zone (EZ) at the fovea; (4) the presence of disorganization of retinal inner layers (DRIL); (5) the presence of subretinal fluid (SF); (6) the presence and the number of hyperreflective foci (HF); and (7) the vitreoretinal relationship.
Forty-five eyes from 35 patients with a mean age of 70.4 ± 7.6 years were evaluated. Sixteen patients (46%) were men. At baseline, 22% of the eyes were phakic. DME duration was 4.3 ± 1.3 years. All eyes received intravitreal injections of anti-VEGF and/or short-action corticosteroids prior to the FAc implant (6.9 ± 5.3). The mean BCVA at baseline was 42.1 ± 18.4 ETDRS letters, with an average increase of +14.1 ETDRS letters observed 3 years after FAc implant (p <0.001). The mean CST decreased by 182.9 μm from the baseline to 36 months (p <0.001). After the FAc implant, presence of SF (from 18.6% to 6.7%), EZ/ELM disruption (from 72.1% from 53.3%) and presence of IRC (from 97.7% to 64.4%) significantly decreased by month 6 (p<0.05) and stabilized until end of follow-up. Similar trends, without statistical significance, were observed in presence of HF and DRIL. No variation was observed in vitreomacular interface, with no abnormalities since baseline. According to ESASO classification, staging of diabetic maculopathy went from 76% eyes with advanced DME to 14% at 36 months and from 24% of eyes with early DME at baseline to 86 % with early DME at 36 months.
This analysis suggests that intravitreal FAc implant is effective in the improvement of several OCT parameters, namely decrease in CST, decrease in cysts, improvement in EZ / ELM disruption and decrease in the presence of FS, thus showing that FAc implant allows an improvement in both the parameters associated with inflammation / edema and those associated with structural changes in the retina. The treatment of persistent and recurrent DME with FAc implant also proves to be effective, and this study has shown that there are anatomical and functional gains, maintained over 3 years.