The effect of capsule tension ring on posterior capsule opacification: A meta-analysis

Background: Posterior capsule opacification is one of the most common complications after cataract surgery. Studies have suggested that the introduction of a capsule tension ring might play a critical role in the prevention of capsule opacification, yet quantitative evidence is still lacking. This work consists of a meta-analysis on available data in order to explore the influence of a capsule tension ring on posterior capsule opacification. Methods: A comprehensive review of the literature on capsule tension ring and posterior capsule opacification was carried out using the Embase, Pubmed, Web of Science, and Cochrane electronic databases. The selected studies included randomized controlled trials, retrospective studies and prospective studies published before June 2020. The studies of interest were selected by two reviewers independently from the included studies. Odds ratios (ORs) and standardized mean differences (SMD) were used in order to assess the association. A fixed-effects model or a random-effects model was applied to combine data according to heterogeneities. Sensitivity analysis was used to assess the heterogeneity of the studies. Publication bias was estimated using the Egger test. Statistical analysis was performed using the stata15.1 software. Results: The meta-analysis included in total 8 studies involving 379 cases and 333 controls. There was a statistically significant difference of Nd:YAG laser capsulotomy rate (OR=0.241, 95% CI: 0.145, 0.400 I2=42.1%) between the capsule tension ring group and the control group, indicating that the tension ring reduced the Nd:YAG laser capsulotomy rate. Further studies with continuous data also revealed that the use of capsule tension ring was associated with a lower posterior capsule opacification score (SMD = -1.402, 95% CI: -2.448, -0.355 I2=95.0%). The sensitivity analysis suggested that the result of the re-combined analysis did not change notably, indicating that the result was reliable and stable. Both pooled analysis showed no evidence of publication bias. Conclusion: The findings of this meta-analysis confirmed that capsule tension ring might reduce capsule opacification. Further studies should be made to validate the result.