Dexamethasone intravitreal implants for retinal vein occlusion in a clinical setting

Editor, S tandard treatments of macular oedema (ME) due to retinal vein occlusion (RVO) include macular laser photocoagulation (The Branch Vein Occlusion Study Group 1986), intravitreal injections of antivascular endothelial growth factor agents (Brown et al. 2010; Boyer et al. 2012) and intravitreal corticosteroid injection. Recently, a sustained-release biodegradable dexamethasone intravitreal implant (DEX implant; Ozurdex ; Allergan, Inc., Irvine, Calif.) has been shown to reduce ME and improve visual acuity (VA) in patients with RVO (Haller et al. 2010, 2011). The aim of our study was to report the results and safety of DEX implant in clinical settings. The charts of 55 consecutive patients were reviewed. As a general rule, DEX implant was not used for patients requiring more than one medication to control their intraocular pressure (IOP), having undergone filtering surgery or with a history of steroidinduced IOP. During the treatment period, patients attended consultations every 2 months. At each visit, a complete eye examination was performed with best corrected visual acuity (BCVA) measurement using the ETDRS chart and OCT assessment of central macular thickness (CMT) (SDOCT, Spectralis , HRA Heidelberg, Heidelberg, Germany and Cirrus OCT, Carl Zeiss, Dublin, CA, USA). Reinjections were done from the 4th month of follow-up, when the retinal thickness was greater than 250 lm and a 2-line BCVA loss was observed. Changes in BCVA and CMT from baseline were analysed using a paired student’s t-test with significance level at ≤0.05. The main safety parameter measured was the IOP changes. Increased IOP was defined when intraocular pressure (IOP) rose above 24 mmHg or IOP increased by 10 mmHg. Patients’ mean age was 66 12 years. Proportions of central andbranch RVO among studied eyes were 54%and 46%, respectively. The mean BCVA (LogMar) was 0.69 35 at baseline, increased significantly to 0.54 0.42 at 2 months (p < 0.001) and then decreased to 0.57 0.42 at 6 months and 0.64 0.53 at 12 months. A 15-letter gain in BCVA from baseline was achieved by 32% and 22% of eyes at 2 and 12 months, respectively. At 2 months, the mean CMT significantly decreased from 589 178 lm at baseline to 300 103 lm (range: 184–787) (p < 0.001), with a mean reduction of 289 75 lm. At 6 and 12 months, the mean CMT was of 386 192 lm (range: 181–962) (p < 0.001) and 293 111 lm (range: 216–575) (p < 0.001), respectively. Reinjections were needed in 43%, 58% and 56% of patients at 4, 6 and 12 months, respectively. After 4, 6 and 12 months of follow-up, 58%, 42% and 11% of patients had only one injection, respectively. We observed a mean interval of 5 months between the first and second injection and 5 months between the second and third injection. Two months after DEX implant injection, the IOPwas elevated in 28%of patients. These patients were successfully managed with topical IOP-lowering medication. None required laser or surgical intervention. These IOP results were similar to those of the GENEVA study, where IOP-lowering medication was needed in 26% of cases (Haller et al. 2011). Our results were also in accordance with the GENEVA study in terms of efficacy on VA and ME (Haller et al. 2010, 2011), but differed in terms of duration of DEX implant efficacy and frequency of reinjections. Indeed, differently from the Geneva study where no control visit was done between the