The aim of this study was to evaluate the effect of vitrectomy with sterile air in treatment of idiopathic macular hole (IMH) by using Meta-analysis.

The comparison of vitrectomy with C3F8 and sterile air in treatment of IMH from Chinese and English literature was identified after searching of Pubmed, Web of Science, Cochrane Library, Embase and Wanfang medical database. According to the inclusion and exclusion criteria, the data were extracted and divided into two groups: C3F8 group and sterile air group. Then Meta-analysis was performed to evaluate the postoperative vision, operation time, postoperative prone posturing period and macular hole closure rate using the ReviewManager 5.4 software. The mean difference (MD) and a confidence interval (CI) of 95% were used to describe the effect sizes of continuous data. Heterogeneity was examined by Q test and I² statistics. When P<0.05 or I²>50%, the heterogeneity was considered to be greater, and performed with a random effects model; otherwise, the fixed effects model was performed.

In all databases, 84 literatures were retrieved. After excluding the repetitive literatures, the literatures with in consistent contents or incomplete main outcome indicators and the literatures with data that cannot be extracted, there were 6 studies recruited for meta-analysis, including 505 eyes (255 eyes in air group and 250 eyes in C3F8 group). After the random bias risk assessment, 3 literatures were rated as high risk and then Minors assessment was performed. These were rated as qualifited. 6 literatures involved were rated as low risk after using follow-up bias, report bias and other biases analysis. There was non-significant heterogeneity between the air group and C3F8 group in operation time (I²=0) and significant heterogeneity in postoperative prone posturing period (I²=99%). After fixed effects model analysis, it was found that there were statistical significance difference in operation time between them (MD=-6.34, 95%CI: -8.98 to -3.71; P<0.05). After a random effects model analysis, there also was shown the significance difference in postoperative prone posturing period bewteen them (MD=-18.90, 95%CI: -24.78 to -13.01; P<0.05). There was non-significant heterogeneity between the air group and C3F8 group macular hole closure rate (I²=0) and significant heterogeneity in postoperative vision (I²=66%). However, after a random effects model analysis, there was no significant difference between the air group and C3F8 group in postoperative vision (MD=0.00, 95%CI: -0.16 to 0.16; P>0.05). After fixed effects model analysis, there was no significant difference in macular hole closure rate between them (MD=0.91, 95%CI: 0.45 to 1.83; P>0.05).

Vitrectomy with sterile air was more effective in reducing operation time and postoperative prone posturing period in the treatment of idiopathic macular hole.