Comparison of available clinical and imaging tools to assess good positioning of a fluocinolone acetonide implant (Iluvien^?) in the vitreous cavity after injection

Introduction. - Sustained-release corticosteroid implants are injected into the vitreous cavity using preloaded pens. The fluocinolone (FAc) implant is approximately half the size of the dexamethasone implant (Dex-I). It is simply introduced in the vitreous base rather than propelledinto the vitreous cavity as is Dex-I. Verification of its positioning after injection is thus difficultby indirect ophthalmoscopy. The goal of our study is to compare the performance of availableclinical and imaging tools to confirm the presence of the FAc in the vitreous cavity following injection. Methods. - Twelve eyes of 12 consecutive patients were included in a retrospective, single-center, observational study carried out at the Bordeaux University Hospital, France. All patients were injected with the FAc after pupil dilation, and presence of the implant was immediately checked by indirect biomicroscopy, wide-field retinography (Clarus((R)), Carl-Zeiss-Meditec, Dublin, CA, USA) and ultra-wide-field retinography (California((R)), Optos, Edinburgh, United-Kingdom). Seven days later, a B-mode ultrasonography (10 MHz, AVISO, Quantel-medical, France) and an UBM ultrasonography (50 MHz, AVISO, Quantel-medical, France) were performed. Results. - Indirect biomicroscopy and wide-field retinography detected 4/12 implants (33.3%). Ultra-wide-field retinophotography detected 6/12 implants (50%). All the implants seen using indirect biomicroscopy and wide-field retinography were also visualized with ultra-wide-field. B-mode ultrasonography showed 5/12 implants (41.6%) and UBM 9/12 implants (75%). Finally, one implant dislocated into the anterior chamber and was seen in the iridocorneal angle ongonioscopy. Conclusion. - Objective confirmation of the proper positioning of the FAc implant in the vitreous cavity is mandatory. If both indirect ophthalmoscopy and anterior examination fail to detectit, ultra-wide field retinography along with UBM ultrasonography, if necessary, appear to be the two best imaging modalities to use. (c) 2023 Published by Elsevier Masson SAS.