Safety and long-term efficacy of repeated dexamethasone intravitreal implants for the treatment of cystoid macular edema secondary to retinal vein occlusion with or without a switch to anti-VEGF agents: a 3-year experience

Anatomical and Functional Results of Early or Late Switching from Anti-VEGF to Dexamethasone Implant in Case of Poor Anatomical Response in Naïve Patients with Macular Edema Secondary to Branch Retinal Vein Occlusion

PURPOSE

To compare the outcomes of early or late switching from intravitreal (IV) anti-vascular endothelial growth factor (anti-VEGF) injection to IV Dexamethasone (DEX) implant injection in treatment-naïve patients with macular edema secondary to branch retinal vein occlusion.

METHODS

This study included 68 eyes of 68 treatment-naïve BRVO patients who started anti-VEGF treatment. After the loading dose, the patients were divided into two groups: Early DEX group (n:34) (DEX implant treatment started after 3 loading doses) and Late DEX group (n:34) (DEX implant treatment started after 6 months). Visual acuity and examination findings were recorded at baseline, 3rd, 6th, and 12th month follow-ups. Optical coherence tomography data were recorded for central macular subfield thickness assessment.

RESULTS

A total of 30 (44.1%) women and 38 (55.9%) men participated, and the average age was 67.6 ± 6.4 years. The mean letter gains at week 52 was 15.1 and 20.9 in the Early DEX and Late DEX groups, respectively. The group with the highest gain of ≥15 letters was the Late DEX group (26/34 patients) and the gain of ≥15 letters was 14/34 in the Early DEX group (p: 0.006). At week 52, the anatomical gain was 115.3 µm and 136.9 µm in the Early DEX and Late DEX groups, respectively.

CONCLUSIONS

A gain of 15 or more letters was demonstrated to be higher in patients who switched to DEX implant late after anti-VEGF treatment. If it is necessary to switch, the late switch may be more effective for more visual gain at the end of the first year.

Short-term effectiveness prognostic factors after dexamethasone intravitreal implant in macular edema due to retinal vein occlusion

INTRODUCTION

The aim of this study was to describe functional and anatomical changes (best-corrected visual acuity [BCVA], central macular thickness [CMT], and central macular volume [CMV]) in patients with macular edema (ME) secondary to retinal vein occlusion (RVO) treated with intravitreal dexamethasone implant (IDI) and identify its clinical predictors in a real-world setting.

METHODS

Data from 111 patients who underwent IDI to treat RVO-associated ME were retrospectively reviewed. Demographic, preoperative, and postoperative variables were assessed using a logistic regression analysis to determine predictors of visual and anatomical improvement.

RESULTS

Mean BCVA, CMT, and CMV improved from baseline after IDI (p < 0.001). The strongest predictors of different treatment outcomes were: a baseline BCVA ⩽60 ETDRS letters (OR = 50.600; p < 0.001) and first IDI injection (OR = 2.988; p < 0.001) for BCVA gain ⩾15 Early Treatment Diabetic Retinopathy Study (ETDRS) letters; a baseline BCVA ⩽60 ETDRS letters (OR = 7.893; p = 0.002) and non-chronic ME (OR = 3.875; p = 0.019) for BCVA ⩾80 ETDRS letters achievement; a baseline CMT ⩾400 µm (OR = 49.083; p < 0.001) and a baseline CMV ⩾12 mm³ (OR = 4.235; p < 0.001) for CMT reduction ⩾50%; and a baseline CMT ⩾400 µm (OR = 11.471; p < 0.001) and a baseline CMV ⩾12 mm³ (OR = 10.284; p < 0.001) for CMV reduction ⩾15%.

CONCLUSION

This study confirmed the effectiveness of IDI to treat ME secondary to RVO and identified new predictive factors for two visual (⩾15 ETDRS letters gain and BCVA ⩾80 ETDRS letters) and two anatomical outcomes (>50% CMT and >15% CMV reduction).

LONG-TERM INCIDENCE AND RISK FACTORS OF OCULAR HYPERTENSION FOLLOWING DEXAMETHASONE-IMPLANT INJECTIONS: THE SAFODEX-2 STUDY

PURPOSE

To analyze the incidence, risk factors, and time to onset of ocular hypertension (OHT) after intravitreal injections (IVI) of dexamethasone implant and to evaluate the long-term cumulative probability of intraocular pressure elevation.

METHODS

Eyes of patients having received at least one dexamethasone implant IVI between October 2010 and February 2015 were included in the present study. Ocular hypertension was defined as intraocular pressure > 25 mmHg and/or an increase of 10 mmHg over the follow-up period compared with baseline intraocular pressure.

RESULTS

Four hundred ninety-four eyes were studied in 410 patients. For a total of 1,371 IVI, the incidence of OHT was 32.6% in the study eyes with a mean follow-up period of 30 months (3-62.5) and a median follow-up of 29 months. Pressure-lowering treatment was introduced for 36.9% of eyes. Topical treatment alone was sufficient to manage OHT in 97%. Young age, male sex, uveitis and retinal vein occlusion, and glaucoma treated with a double- or triple-combination topical pressure-lowering medication were found to be risk factors for OHT. The incidence of OHT did not change with an increase in the number of IVI, and there was no cumulative effect, defining by an increase of the incidence of OHT in patients after repeated IVI (P = 0.248).

CONCLUSION

This study confirmed that OHT is of moderate incidence, transient, controlled by topical treatment and provides data on the long-term cumulative probability of intraocular pressure elevation in a large cohort of eyes treated with dexamethasone implant IVI. Repeat injections of dexamethasone implant neither increase nor decrease the risk of OHT.

Real-life medium term follow-up data for intravitreal dexamethasone implant in retinal vein occlusion

Macular edema (ME) is the most frequent vision threatening consequence after retinal vein occlusion (RVO). In this study, we evaluate the effect of dexamethasone intravitreal implants (DII, Ozurdex) in a real-life cohort of 99 patients with ME due to RVO. All patients who received DII for ME following RVO between 2011 and 2016 at the University Eye Hospital Freiburg, Germany and who had fully accessible electronic medical records were eligible for this study. Most of the patients included in this study were not treatment-naïve: 61 eyes had received prior anti-VEGF drugs, 6 eyes had received intravitreal corticosteroids (triamcinolone) and 15 had been treated with both; 17 eyes were treatment-naïve. Mean follow-up was 312 ± 310 days. Mean visual acuity (VA) was maintained throughout the observation period (mean VA at baseline: 66.7 ± 23.5 letters; at last observation 64.9 ± 28.3). Central retinal thickness (CRT) decreased from 526 ± 179 µm at baseline to 431 ± 199 µm. Mean intraocular pressure (IOP) increased from 14.4 ± 3.1 mmHg at baseline to 17.1 ± 6.3 mmHg. Cataract surgery was performed in 22% of phakic eyes. DII was used as second-line treatment in the majority of cases in this cohort. The fact that mean VA remained unchanged while mean CRT decreased illustrates that morphologic improvement does not always translate into functional gain. Mean IOP was maintained within normal limits and cataract formation was as expected in this age group.

Comparison between Ozurdex and intravitreal anti-vascular endothelial growth factor treatment for retinal vein occlusion-related macular edema: A systematic review and meta-analysis of randomized controlled trials

This systematic review aimed to evaluate the effectiveness and safety of intravitreal dexamethasone (DEX) implant and intravitreal anti-vascular endothelial growth factor (VEGF) treatments for macular edema (ME) secondary to retinal vein occlusion (RVO), central retinal vein occlusion (CRVO), and branch retinal vein occlusion (BRVO). The electronic databases comprehensively searched for the studies that compared DEX with anti-VEGF treatments in patients suffering from RVO-related ME. The effectiveness was estimated using best-corrected visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP). All data were analyzed by Review Manager (RevMan) 5.3. According to the meta-analysis from five randomized control trials, both DEX implant and anti-VEGF agent treatments were effective, but no significant differences in BCVA and CRT were observed between these two treatments. Novartis’ two studies indicated that anti-VEGF agents significantly reduced the CRT compared with DEX implant at 6 months [weighted mean difference: 158.53 μm, 95% confidence interval (CI): (71.09, 245.96), P = 0.0004]. Furthermore, anti-VEGF agents showed some advantages on cataract formation [risk ratio (RR): 3.43, 95% CI: (1.35, 8.71), P = 0.009] and other adverse events [RR: 1.19, 95% CI: (1.09, 1.31), P = 0.0002] without heterogeneity (P = 0.20, I² = 35%). Anti-VEGF agents were also effective treatments for cataract formation or less adverse events for RVO-related ME. In contrast, DEX implant had higher risk for IOP elevation and lower cataract incidence than anti-VEGF agents. Hence, complementary and alternative treatments are expected.

Baseline clinical features predict visual outcome in young patients with central retinal vein occlusion

PURPOSE

To evaluate prognostic factors in young patients with central retinal vein occlusion (CRVO).

METHODS

Retrospective case series. CRVO patients aged ≤ 50 and follow-up ≥ 6 months were enrolled. The best corrected visual acuity (BCVA) and central retinal thickness (CRT) at baseline, 3 months, 6 months, and last visit were documented. Severity of retinopathy was graded by comparing to standard photos. Prognostic factors associated with visual outcome at 6 months were evaluated by multiple linear regression models.

RESULTS

A total of 73 eyes from 69 patients with mean age 37.6 ± 8.5 were enrolled. Forty-seven (68%) patients were male. The mean follow-up duration was 25.9 ± 23.0 months. LogMAR BCVA improved from 0.979 ± 0.785 at baseline to 0.594 ± 0.748 at the 6 months (p < 0.001) and CRT improved from 475 ± 222 μm to 299 ± 104 μm (p < 0.001). Forty-eight (66%) eyes required anti-vascular endothelial growth factor (anti-VEGF) treatment. The mean number of injections was 2.25 ± 1.41 in the first 6 months and 75% of eyes received ≦ 3 injections during the clinical course. The baseline BCVA (coefficient 0.518, p < 0.001), grade of retinal hemorrhage (coefficient 0.230, p = 0.006), grade of retinal venous engorgement (coefficient 0.238, p = 0.011), grade of optic disc edema (coefficient - 0.226, p = 0.005), and diabetes mellitus (coefficient 0.264, p = 0.047) were the independent factors associated with visual outcome at 6 months.

CONCLUSIONS

Baseline clinical features are useful for the prediction of visual outcome at 6 months in young CRVO patients.

Simultaneous intravitreal dexamethasone and aflibercept for refractory macular edema secondary to retinal vein occlusion

PURPOSE

To assess the functional and anatomical outcomes of concurrent administration of aflibercept injection and dexamethasone (DEX) implant in patients with macular edema (ME) secondary to retinal vein occlusion (RVO), refractory to each of the two drugs previously administered as monotherapy. Secondary outcomes included the number of retreatments required in a 12-month follow-up and safety.

METHODS

This is a prospective, interventional case series of consecutive patients with refractory ME secondary to RVO, followed over a year. One injection of aflibercept was followed by a DEX implant on the same day; retreatment was driven by the persistence of ME on SD-OCT at least 4 months after the previous combined therapy. Central retinal thickness (CRT), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were collected at 1 month and then every 2 months until the end of follow-up.

RESULTS

Thirty eyes of 30 Caucasian patients were enrolled; mean duration of RVO before the first combined treatment was 25 ± 5 months (range 11 ± 30). Baseline BCVA was 0.73 ± 0.5 LogMAR, with no significant changes at 12 months (0.77 ± 0.51 μm, p = 0.2). Baseline CRT was 578.3 ± 161 μm, reducing to 352.5 ± 81 μm at 12 months (p = 0.003). Thirteen eyes (43.3%) required a second treatment. Twenty eyes (66.6%) showed no ME at the end of follow-up. One patient (3.3%) required topical IOP-lowering therapy during the study.

CONCLUSION

In eyes with ME secondary to RVO unresponsive to either aflibercept or DEX administered singularly, a combination therapy with simultaneous administration of aflibercept and DEX was effective in resolving ME, despite the absence of visual improvement. Earlier combined treatment in the course of the disease might lead to better functional outcomes.

Protective effects of hydrogen gas in a rat model of branch retinal vein occlusion via decreasing VEGF-α expression

Background

Oxidative stress (OS) is an essential factor in the pathogenesis of branch retinal vein occlusion (BRVO). Studies have demonstrated the role of hydrogen gas in the regulation of OS. This study was designed to evaluate the efficacy of hydrogen gas on the BRVO rat model.

Methods

Twenty-four BRVO rats were randomly divided into two groups: the hydrogen gas (H) group (42% H₂, 21% O₂, 37% N₂) and the model (M) group (21% O₂, 79% N₂). Rats in the H group inhaled hydrogen gas for 8 h every day up to 30 d post-occlusion. Twelve age-matched healthy rats served as the control (C) group. Retinal function and morphology were detected at 1, 7, 14 and 30 d post-occlusion. Furthermore, the expression of vascular endothelial growth factor (VEGF-α) was detected by immunofluorescent staining.

Results

Full-field electroretinography (ffERG) revealed that the amplitude of the b-wave (dark-adaptation 3.0 response), the amplitude of the OPs2 wave and the light-adapted flicker response in the H group were all higher than those in the M group at 7 d post-occlusion (all p < 0.05). The reopen time of occlusive retinal vessels in the H group was 2.235 ± 1.128 d, which was shorter than that in the M group (4.234 ± 2.236 d, p < 0.05). The rats in the H group had a thinner IPL + GCL + NFL and an increased total retina compared with those in the M group at 3 d post-occlusion (p < 0.05), while the rats in the H group had a thicker INL, IPL + GCL + NFL and total retina compared with those at 7, 14 and 30 d post-occlusion (p < 0.05). Moreover, the flow velocity of ear vein blood was increased in the H group compared with that in the M group (p < 0.05). The expression of VEGF-α in the H group was dramatically decreased compared with that in the M group at 1, 7 and 14 d post-occlusion (p < 0.05), while the expression kept in similar level at 30 d post-occlusion (p > 0.05).

Conclusions

Our findings demonstrate that inhalation of hydrogen gas could alleviate retinal oedema, shorten reopen time and improve retinal function, and the potential mechanism might be related to a decrease in VEGF-α expression.