A total of 1413 potential references were obtained from PubMed (n = 401), Embase (n = 911), and the Cochrane Library (n = 113). After the exclusion of 282 duplicate references, the remaining articles were assessed for eligibility. Finally, 21 articles from 10 RCTs, 3 prospective non-RCTs, and 21 articles from 17 retrospective studies were included in this meta-analysis (Fig. 1). No evidence of asymmetry was noted by visual inspection in all funnel plots. (Supplementary-2,3,4,5)
Study Characteristics
A total of 2409 eyes were included in our study. The mean age of the patients was 62.19 years (range, 56.2–67.8 years). The follow-up duration ranged from 1 month to 12 months. The baseline BCVA ranged from 0.2 to 0.96 logMAR, and the baseline CRT ranged from 261.1 to 605.3 µm. 5 studies recruited patients with resistant DME, while 25 studies recruited patients with non-resistant DME. Eight of these studies included patients with naïve DME. Details regarding the characteristics of the included studies are summarized in Table 1.
Table 1
Characteristics of studies
Study | Study type | Year | Follow up time(m) | Persisted DME Not persisted DME Naïve DME | Treatment | Number (eye) | Age (mean) | Gender (M/F) | Pseudophakia/phakia | A1C | BCVA (logMAR) (mean) | CRT (mean) |
Aksoy et al | Retrospective | 2020 | 3 | Persisted DME | 1. Aflibercept 2. Ozurdex | 34 37 | 59.3 61.3 | 18/16 1819 | 6/31 5/23 | N/A | 0.74 0.72 | 529.1 532.04 |
Aydin et al | Retrospective | 2020 | 12 | Not persisted DME | 1. Ranibizumab 2. Ozurdex | 30 22 | 60.2 58.2 | 15/15 9/13 | N/A | 7.15 7.32 | 0.75 0.83 | 466.1 524.2 |
Bolubasi et al | Retrospective | 2019 | 3 | Not persisted DME | 1. Bevacizumab 2. Ozurdex | 32 25 | 56.4 65.1 | 13/19 9/25 | 9/23 15/10 | 7.8 7.8 | 0.6 0.8 | 490.3 540 |
Busch et al | Retrospective | 2019 | 12 | Persisted DME | 1. Anti-VEGF 2. Ozurdex | 38 38 | 61.2 63.1 | 17/21 22/16 | 15/23 18/20 | N/A | 0.54 0.54 | 496.2 504.7 |
Callanan et al | RCT | 2017 | 12 | Not persisted DME | 1. Bevacizumab 2. Ozurdex | 182 181 | 63.7 63.4 | 116/62 112/69 | 62/120 54/127 | N/A | 0.49 0.50 | 471 465 |
Ceravolo et al | Retrospective | 2020 | 3/2 | Naïve DME | 1. Ranibizumab 2. Ozurdex | 75 81 | 70.8 70.4 | 110/47 112/49 | N/A | N/A | 0.67 0.74 | 261.1 271.5 |
Comet et al | Prospective | 2020 | 12 | Naïve DME | 1. Ranibizumab 2. Aflibercept 3. Ozurdex | 19 20 21 | 65.6 69.6 66.3 | 8/11 11/9 12/9 | 9/10 8/12 9/12 | 7.5 7.8 7.6 | 0.45 0.56 0.52 | 450.1 469.5 464.5 |
Demircan et al | Retrospective | 2018 | 3 | Not persisted DME | 1. Ranibizumab 2. Ozurdex | 101 35 | 58 60.3 | 50/51 19/16 | N/A | N/A | 0.8 1.0 | 605.3 643.9 |
Giles et al (BEVODEX) | RCT | 2014 | 12 | Not persisted DME | 1. Bevacizumab 2. Ozurdex | 42 46 | 62.2 61.4 | 26/16 30/16 | N/A | 7.8 7.7 | 0.57 0.59 | 503 474.3 |
Hernández-Bel et al | Retrospective | 2019 | 12 | Not persisted DME | 1. Aflibercept 2. Ozurdex+ Aflibercept | 15 15 | 69.4 66.2 | N/A N/A | 3/12 4/11 | 7.6 8.2 | 0.28 0.19 | 411 411.4 |
Karakurt et al | Retrospective | 2018 | 1 | Not persisted DME | 1. Ranibizumab 2. Aflibercept 3. Ozurdex | 81 53 54 | 62.94 65.70 59.47 | 40/41 30/23 36/18 | N/A | N/A | N/A | N/A |
Kaya et al | RCT | 2021 | 12 | Naïve DME | 1. Ranibizumab 2. Ozurdex+ Ranibizumab | 34 34 | 66.2 64.6 | 12/12 12/10 | 10/24 12/22 | 7.0 7.0 | 0.66 0.74 | total 597 |
Limon et al | Prospective | 2021 | 3 | Persisted DME | 1. Bevacizumab 2. Ozurdex+ Bevacizumab | 30 35 | 63.20 64.34 | 14/16 12/17 | 30/0 31/4 | N/A | 0.83 0.82 | 434.42 462.34 |
Lin et al | Retrospective | 2021 | 6 | Not persisted DME | 1.Aflibercept 2. Ozurdex+ Aflibercept | 50 52 | 63.4 65.1 | 26/14 20/21 | 16/34 29/23 | 7.4 7.5 | 0.63 0.64 | 420.6 433.8 |
Maturi et al (2015) | RCT | 2015 | 12 | Not persisted DME | 1. Bevacizumab 2. Ozurdex+ Bevacizumab | 19 21 21 | 61 total Total | 13/17 Total Total | 7/12 8/13 | N/A | 0.42 0.4 | 412 372 |
Maturi et al (2018) | RCT | 2018 | 6 | Not persisted DME | 1. Ranibizumab 2. Ozurdex+ Ranibizumab | 64 63 | 66* 64* | 28/36 34/31 | 32/32 26/39 | 7.4* 7.1* | 0.44 0.44 | 396 375 |
Mastropasqua et al | Retrospective | 2019 | 6 | Naïve DME | 1. Ranibizumab 2. Ozurdex | 25 25 | 61.4 62.1 | 13/12 10/15 | 13/12 14/11 | N/A | 0.4 0.5 | 460.3 479.1 |
Mishira et al | RCT | 2021 | 4 | Not persisted DME | 1. Ranibizumab 2. Ozurdex | 70 70 | 63.15 63.3 | 38/32 37/33 | N/A | N/A | 0.96 0.96 | 460 471 |
Muftuoglu et al | retrospective | 2021 | 3 | Not persisted DME | 1. Ranibizumab 2. Ozurdex | 18 19 | 62.22 61.84 | 13/5 19/10 | 7/11 7/12 | 6.72 7.26 | 0.27 0.34 | 509 533 |
Ozsaygili et al | RCT | 2020 | 12 | Naïve DME | 1.Aflibercept 2.Ozurdex | 50 48 | 66.4 64.8 | 15/14 20/13 | 23/27 19/29 | 8.2 8.4 | 0.75* 0.77* | 576.5* 615.2* |
Podkowinski et al | RCT | 2019 | 5 | Not persisted DME | 1. Ranibizumab 2.Ozurdex | 9 9 | 66.89 64.56 | N/A | N/A | N/A | 0.2 0.36 | 440.89 471.33 |
Routier et al | Retrospective | 2021 | 2 | Naïve DME | 1. Anti-VEGF 2.Ozurdex | 55 10 | total 65.9 | total 19/26 | 26/39 | N/A | 0.56 0.56 | 498 451 |
Rübsam et al | Prospective | 2021 | 1 | Not persisted DME | 1. Anti-VEGF 2.Ozurdex | 40 19 | total 58.9 | total 39/12 | N/A | N/A | total 0.41 | 455.5 471.6 |
Sever et al | Retrospective | 2017 | 12 | Not persisted DME | 1. Ranibizumab 2.Ozurdex | 44 40 | total 56.2 | N/A | 5/39 10/30 | N/A | 0.75 0.75 | 372.6 376.6 |
Shah et al | RCT | 2016 | 7 | Not persisted DME | 1.Bevacizumab 2.Ozurdex | 23 27 | 61 65 | 13/10 12/15 | 9/14 14/13 | N/A | 0.52 0.52 | 485 458 |
Sharma et al | RCT | 2019 | 6 | Persisted DME | 1.Anti-VEGF 2.Ozurdex | 20 20 | 56.42 58.15 | N/A | 0/45 | N/A | 0.51 0.56 | 460.95 452.25 |
Shin et al | Retrospective | 2017 | 3 | Not persisted DME | 1.Bevacizumab 2.Ozurdex | 25 20 | 59.1 61.5 | 16/9 10/10 | 7/4 8/3 | N/A | 0.63 0.78 | 451.3 510.3 |
Thomas et al | Retrospective | 2016 | 3 | Persisted DME | 1. Ranibizumab 2.Ozurdex | 11 11 | total 62 | total 4/7 | 4/7 7/4 | total 6.51 | 0.39 0.42 | 421.1 461.3 |
Vujosevic et al 2017 | Retrospective | 2017 | 1 | Naïve DME | 1. Ranibizumab 2.Ozurdex | 26 23 | 65.2 66.9 | 15/11 15/8 | N/A | 7.5 7.3 | 0.55 0.68 | 518 594.6 |
Vujosevic et al 2020 | Retrospective | 2020 | 4/3 | Naïve DME | 1. Ranibizumab 2.Ozurdex | 18 15 | 63.8 63.3 | N/A | N/A | 8.4 8.7 | 0.36 0.49 | 420.48 565.5 |
*median DME: diabetic macular edema |
Bcva Change
Overall, twenty-seven trials reported the outcome of BCVA change. Four of these trials included patients with resistant DME. The pooled results revealed no significant differences between the Ozurdex group and anti-VEGF group, with high heterogeneity being noted in patients with nonresistant DME (MD: 0.00, 95% CI: −0.06–0.05, I2 = 97%, Fig. 2 − 1). However, in patients with resistant DME, a significant difference was noted between the Ozurdex group and anti-VEGF group (MD: 0.12, 95% CI: 0.02–0.21, I2 = 0%, Fig. 2). Subgroup analysis of the treatment modality in patients with nonresistant DME revealed no significant difference between anti-VEGF therapy and Ozurdex therapy. Moreover, no significant difference was noted between anti-VEGF therapy and combined anti-VEGF + Ozurdex therapy (Supplementary-6). In both linear and nonlinear meta-regression models, the mean age, treatment duration, baseline BCVA, baseline CRT, and HbA1C level were not associated with the weighted mean difference (WMD) in BCVA change between the Ozurdex and anti-VEGF groups in patients with nonresistant DME. However, the MD in CRT change was significantly associated with the MD in BCVA change in the nonlinear meta-regression model (Supplementary-7). Furthermore, no significant association was noted between the MD in BCVA change and lens status. Although a significant association was noted between the MD in BCVA change and the proportion of patients with pseudophakia (P = 0.05, deviance = 6.67, Supplementary-7 ), this analysis was not compatible with the clinical status.
Crt Decrease
Twenty-eight trials reported the outcome of CRT decrease. Five of these trials recruited patients with resistant DME. Pooled analysis of patients with resistant DME revealed a greater decrease in CRT in the Ozurdex group than in the anti-VEGF group (WMD: 65.37, 95% CI: 3.62 − 127.13, P < 0.01, I2 = 83%, Fig. 3); however, high heterogenicity was noted. Moreover, analysis of patients with nonresistant DME revealed a significant difference between the Ozurdex group and anti-VEGF group (WMD: 49.58, 95% CI: 19.27–79.89, I2 = 94%, Fig. 3). Subgroup analysis revealed a significant difference between anti-VEGF therapy and Ozurdex therapy. Although a combination of Ozurdex and anti-VEGF could not lead to a significantly greater decrease in CRT than either therapy alone, a trend favoring the combination therapy in terms of CRT decrease was noted (Supplementary-8). The results of meta-regression revealed no association between CRT decrease and the mean age, treatment duration, baseline BCVA, baseline CRT, and HbA1C level. However, in the nonlinear meta-regression model, a significant association was noted between the MD in CRT decrease and baseline CRT. The parabola in the meta-regression revealed that Ozurdex therapy led to a greater decrease in CRT if the baseline CRT was more than 413um (P = 0.033, deviance = 125.66, Supplementary-9).
Iop Change
A total of 10 trials reported the outcome of IOP change. Only one of these trials recruited patients with resistant DME. The pooled results revealed no significant difference in IOP change between the Ozurdex group and anti-VEGF group (WMD: -0.42, 95% CI: -1.00–0.15, I2 = 40%, Supplementary-10). Moreover, subgroup analysis of the treatment modality in patients with nonresistant DME revealed that Ozurdex therapy did not lead to a significant increase in IOP. (Supplementary-10) Meta-regression could not detect the association between IOP change and the baseline IOP, mean age, and treatment duration.
Severe Ocular Adverse Events
Overall, 13 trials reported the outcome of the occurrence of severe ocular adverse events. Three of these trials recruited patients with resistant DME. The severe ocular adverse events reported in these trials included endophthalmitis, retinal detachment, and glaucoma that could not be controlled by glaucomatous eye drops. The pooled results revealed no significant difference between the Ozurdex group and anti-VEGF group, with low heterogeneity being noted(RR: 0.64, 95% CI: 0.28–1.49, P = 0.63, I2 = 0% Supplementary-11)
Risk Of Bias Assessment
Generally, the quality of the 9 included RCTs was moderate, with some “unclear” and “high risk”. “Some concerns” risk of bias was raised in the domain of random sequence generation and allocation concealment due to the incomplete information in the article. “High risk’ in the blinding domain was raised in some studies due to the studies were unmasked. The observational studies were assessed and qualified by (ROBINS-I) tool. Overall, the level of evidence of included studied was downgraded due to high risk of bias of confounding factor, and the moderate risk of bias in measurement of the outcomes. The detail of risk of bias assessment was listed on the Supplement (Supplementary-12,13)