Epiretinal Membrane Vitrectomy With and Without Intraoperative Intravitreal Dexamethasone Implant: A Systematic Review With Meta-Analysis

Purpose: To evaluate the efficacy of vitrectomy combined with intravitreal dexamethasone implant vs. vitrectomy without the implant in patients with epiretinal membrane (ERM) by conducting a systematic review and meta-analysis. Methods: Studies that compared ERM vitrectomy with and without intraoperative dexamethasone implant with a follow-up ≥3 months were included. The primary outcome was mean best corrected visual acuity (BCVA) change between eyes undergoing ERM vitrectomy combined with dexamethasone implant (DEX group) and eyes undergoing ERM vitrectomy alone (control group) at 3 months. Secondary outcomes included mean BCVA change at 6 months and mean optical coherence tomography central macular thickness (CMT) change at both 3-months and 6-months follow-up. Mean differences (MDs) with their 95% confidence interval (95%CI) were calculated. Meta-analyses were based either on random effect model or fixed effect model according to heterogeneity. Results: Four studies were included. At 3 months, ERM vitrectomy combined with dexamethasone implant yielded a greater visual gain compared to vitrectomy alone (MD = 9.7; 95%CI = 2.6–16.8; p = 0.01). However, significant heterogeneity was found. A sensitivity analysis excluding the only retrospective non-randomized study confirmed a greater visual gain in the DEX group (MD = 7.1; 95%CI = 2.7–11.6; p < 0.01), with no heterogeneity. At 6 months, a non-significant but borderline difference in visual gain was shown between in the two groups (MD = 5.1; 95%CI = −0.3–10.5; p = 0.06), with no heterogeneity. Three-month analysis of CMT revealed a greater reduction in the DEX group (MD = −80.2; 95%CI =−149.1–11.2; p = 0.02), but with significant heterogeneity. A sensitivity analysis excluding the only retrospective non-randomized study allowed to reduce heterogeneity, but no difference in 3-months CMT change was found between the two groups (MD = −50.0; 95%CI = −106.2–6.2; p = 0.08). At 6 months, no difference in CMT change was shown between the two groups (MD = −48.5; 95%CI = −120.5–23.5; p = 0.19), with significant heterogeneity. Conclusions: Intraoperative dexamethasone implant in eyes undergoing vitrectomy for ERM provided a better visual outcome at 3 months compared to ERM vitrectomy without the implant, with limited evidence of better anatomic outcome as well. Further studies are needed to ascertain whether dexamethasone implant would ensure a significant long-term visual benefit as a result of a faster reduction of macular thickening.


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Protocol and registration 5 Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.
-Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.

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Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.
3 Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

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Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).
3 Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.
3 Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.

3-4 Risk of bias in individual studies
12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.

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Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means).

Synthesis of results
14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis.

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Section/topic # Checklist item Reported on page # Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

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Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.

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Study selection 17 Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.

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Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.

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Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).

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Results of individual studies 20 For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.

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Synthesis of results 21 Present results of each meta-analysis done, including confidence intervals and measures of consistency.

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Risk of bias across studies 22 Present results of any assessment of risk of bias across studies (see Item 15).

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Summary of evidence 24 Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).

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Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias). For more information, visit: www.prisma-statement.org. Figure S1: Funnel plots of the comparison of BCVA (A) and CMT (B) at 3-month follow-up between ERM vitrectomy with or without intravitreal dexamethasone implant