Ozurdex in the management of the macular edema following retinal vein occlusion in clinical practice

Abstract

Editor, This study aims to evaluate the safety and the efficacy of the dexamethasone drug delivery system (Ozurdex®) in eyes with macular oedema (ME) secondary to retinal vein occlusion (RVO). Figure 1A summarizes the demographic and diagnostic information for our group compared with the characteristics of the GENEVA study (Haller et al. 2011). (A) Summary of the demographics and diagnostics information for our group compared with the characteristics of the GENEVA study. (B) Visual acuity gain up to 15 letters according subtype of retinal vein occlusion. (C) Maximal foveal thickness according subtype of retinal vein occlusion. (D) Percentage of patient with intraocular pressure (IOP) ≥ 25 mmHg during the follow-up. (E) Percentage of patient with IOP ≥ 25 mmHg during the follow-up, according the IOP status at the diagnosis. Complete examination was performed on 220 eyes monthly from baseline to 6 months (M6) including best-corrected visual acuity (BCVA), biomicroscopy, intraocular pressure (IOP), fundus examination; and central retinal thickness (CRT) by optical coherence tomography (OCT) and fluorescein angiography (Spectralis/HRA, Heidelberg, Germany) at M0-1-3-6. Mean BCVA was 41.43 letters ± 20.7 SD and for subgroups 36.3 letters ± 21.3 SD and 44.8 letters ± 19.6 SD (p = 0.018), respectively, for central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Mean OCT CRT was 641.86 μm ± 221.6 SD with 686 μm ± 247.1 SD and 612.4 μm ± 198.8 SD, respectively, for CRVO and BRVO (p = 0.09). Mean IOP was 15.2 mmHg ± 3.2 SD and follow-up was 10.16 months. Best-corrected visual acuity improves to 54.62 letters ± 19.8 SD at M1, 54.17 letters ± 20.9 SD at M3 and 49.12 ± 22.6 SD letters at M6. The proportion of eyes achieving at least a 15-letter improvement from baseline BCVA was 50.8% M3 and 33.9% M6. In general, the response to treatment in both subgroups (BRVO/CRVO) was qualitatively similar to the responses seen in the overall population. But improvement was greater in CRVO subgroup and was particularly marked in the analysis of mean change from baseline BCVA at M6 due to the worse BCVA at baseline in this subgroup (0.97 LogMAR ± 0.43 SD and 0.80 LogMAR ± 0.39 SD; p = 0.018, respectively, for CRVO and BRVO). The mean CRT was 326.8 μm ± 126.9 SD, 362.5 μm ± 184.8 SD and 481.7 μm ± 265.3 SD, respectively, at M1, M3 and M6. For subgroups, the patterns of response differed (Fig. 1C) with better improvement in BRVO compared with the CRVO subgroup at M6, which present an earlier recurrence of ME (p = 0.05). The principal ocular adverse event was subconjunctivals haemorrhages (14.1%). Cataracts developed for 6.8% patients, but no surgery was necessary. No severe adverse effects were reported. The increase in IOP was transient with maximum at M1 (Fig. 1D) followed by a progressive decrease. It was less frequent and lower compared with triamcinolone (Ip et al. 2009) and was more frequent in patients with glaucoma but still transient (Fig. 1E) and proportional to initial IOP. Thirty per cent of patients were re-injected at M6 and 49% were re-injected during the overall follow-up. The mean time for reinjection was 5.3 months. So, treatment by Ozurdex produced a significant improvement in both structure and function in eyes with vision loss due to ME associated with BRVO or CRVO. The greater improvements in visual acuity were accompanied by greater decreases in CRT, but it was not strictly proportional. The percentage of patients with a gain of VA > 15 letters was better than observed in GENEVA (Haller et al. 2011), probably due to the initial differences between the included patient populations enrolled in the studies (Fig. 1A). The incidence of cataract surgery in our study was very low, but the incidence increases with time. So, this rate should be higher after a longer follow-up. In general, our study found a better prognosis in BRVO compared with CRVO both in anatomical and in functional results, proving that these two diseases which are close in terms of clinical aspect are two different diseases in terms of pathophysiology and so progression (Moisseiev et al. 2013). In summary, Ozurdex provides an efficient treatment option with an acceptable risk benefit ratio for the treatment of RVO patients with ME. The response seems to be better on larger ME, low VA and in early RVO patients (<3 months; Yeh et al. 2012). It is important not to neglect IOP increase, so in a high-risk situation, it is preferable to discuss anti-VEGF treatment or to introduce a preventive IOP lowering treatment.