Recurrent Macular Edema in Central Retinal Vein Occlusion Treated with Intravitreal Ranibizumab using a Modified Treat and Extend Regimen.

Background: The aim of this study was to evaluate the stability over time of the individually defined interval of intravitreal ranibizumab injection (IVR) for the treatment of recurrent macular edema (ME) in central retinal vein occlusion (CRVO). Patients and Methods: A case series of treatment naïve patients followed in the Jules Gonin Eye Hospital for macular edema due to central retinal vein occlusion is presented. Patients were treated monthly with IVR until complete absence of fluid on qualitative SD-OCT with a minimum of 5 monthly IVR. Thereafter, they were followed according to a modified treat and extend regimen (mTER). Results: Twelve eyes (12 patients) with ME due to CRVO were included. The mean follow-up period was 31.3 months. Analysis showed that best corrected visual acuity (BCVA), central macular thickness and qualitative spectral domain optical coherence tomography (SD-OCT) showed comparable results under monthly interval, after titration of an individualized interval and when performed in a series. 78 % of treating intervals were within ± 2 weeks of the first individually adjusted interval. The mean first defined interval was 4.3 weeks and the mean interval over time was 5.5 weeks (p = 0.003). There was a trend towards longer interval over time. Conclusion: The adjusted interval of retreatment of patients with ME due to CRVO showed a high stability with a trend toward longer duration over time. An mTER regimen seems to be valuable to follow patients with ME with good stabilization of VA.

Bilateral deep brain stimulation: the placement of the second electrode is not necessarily less accurate than that of the first one.

BACKGROUND: Deep brain stimulation (DBS) is recognized as an effective treatment for movement disorders. We recently changed our technique, limiting the number of brain penetrations to three per side. OBJECTIVES: The first aim was to evaluate the electrode precision on both sides of surgery since we implemented this surgical technique. The second aim was to analyse whether or not the electrode placement was improved with microrecording and macrostimulation. METHODS: We retrospectively reviewed operation protocols and MRIs of 30 patients who underwent bilateral DBS. For microrecording and macrostimulation, we used three parallel channels of the 'Ben Gun' centred on the MRI-planned target. Pre- and post-operative MRIs were merged. The distance between the planned target and the centre of the implanted electrode artefact was measured. RESULTS: There was no significant difference in targeting precision on both sides of surgery. There was more intra-operative adjustment of the second electrode positioning based on microrecording and macrostimulation, which allowed to significantly approach the MRI-planned target on the medial-lateral axis. CONCLUSION: There was more electrode adjustment needed on the second side, possibly in relation with brain shift. We thus suggest performing a single central track with electrophysiological and clinical assessment, with multidirectional exploration on demand for suboptimal clinical responses.

Bilateral deep brain stimulation : the placement of the second electrode is not necessarily less accurate than that of the first one

Introduction La stimulation cérébrale profonde est reconnue comme étant un traitement efficace des pathologies du mouvement. Nous avons récemment modifié notre technique chirurgicale, en limitant le nombre de pénétrations intracérébrales à trois par hémisphère. Objectif Le premier objectif de cette étude est d'évaluer la précision de l'électrode implantée des deux côtés de la chirurgie, depuis l'implémentation de cette technique chirurgicale. Le deuxième objectif est d'étudier si l'emplacement de l'électrode implantée était amélioré grâce à l'électrophysiologie. Matériel et méthode Il s'agit d'une étude rétrospective reprenant les protocoles opératoires et imageries à résonnance magnétique (IRM) cérébrales de 30 patients ayant subi une stimulation cérébrale profonde bilatérale. Pour l'électrophysiologie, nous avons utilisé trois canules parallèles du « Ben Gun », centrées sur la cible planifiée grâce à l'IRM. Les IRM pré- et post-opératoires ont été fusionnées. La distance entre la cible planifiée et le centre de l'artéfact de l'électrode implantée a été mesurée. Résultats Il n'y a pas eu de différence significative concernant la précision du ciblage des deux côtés (hémisphères) de la chirurgie. Il y a eu plus d'ajustements peropératoires du deuxième côté de la chirurgie, basé sur l'électrophysiologie, ce qui a permis d'approcher de manière significative la cible planifiée grâce à l'IRM, sur l'axe médio- latéral. Conclusion Il y a plus d'ajustements nécessaires de la position de la deuxième électrode, possiblement en lien avec le « brain shift ». Nous suggérons de ce fait d'utiliser une trajectoire d'électrode centrale accompagnée par de l'électrophysiologie, associé à une évaluation clinique. En cas de résultat clinique sub-optimal, nous proposons d'effectuer une exploration multidirectionnelle.