[Influence of capsular tension ring implantation on rotational stability of intraocular lenses: a meta-analysis]

Objective: To systematically evaluate the influence of capsular tension ring (CTR) co-implantation on the rotational stability of intraocular lenses (IOLs) following cataract surgery. Methods: A systematic search was conducted in PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and Chinese databases (CNKI, Wanfang, VIP) for randomized controlled trials (RCTs) and non-randomized studies comparing postoperative IOL rotational stability with and without CTR implantation, from inception to June 2025. The primary outcomes were mean absolute IOL rotation and the proportions of eyes with IOL rotation>5°,>10°, and >15°. Secondary outcomes included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), residual astigmatism (RAS), and postoperative complications. Study quality was assessed using the Cochrane Risk of Bias tool 2.0 (RoB 2.0) for RCTs and the modified Newcastle-Ottawa Scale (NOS) for non-randomized studies. Meta-analysis was performed using R software to calculate standardized mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI). Results: A total of 15 studies (5 RCTs and 10 non-randomized studies) involving 1 536 eyes were included (CTR group: 796 eyes, non-CTR group: 740 eyes), with follow-up durations ranging from 3 to 12 months. At the final follow-up, the mean absolute IOL rotation was significantly lower in the CTR group than in the non-CTR group (SMD=-0.45, 95%CI:-0.72 to -0.17, P=0.002), with significant heterogeneity among studies (I²=80.8%, P<0.001). Time-trend analysis showed that the stabilizing effect of CTR was not significant at 1 week postoperatively (P=0.084), but became significant at 1 month (SMD=-0.48, 95%CI:-0.79 to -0.18, P=0.002) and persisted through 6 months or longer (SMD=-0.52, 95%CI:-0.99 to -0.04, P=0.033). The proportions of eyes with IOL rotation>5° (RR=0.50, 95%CI: 0.32 to 0.78, P=0.002) and>10° (RR=0.37, 95%CI: 0.17 to 0.81, P=0.014) were significantly lower in the CTR group, whereas no significant difference was found for rotation>15° (P>0.05). Subgroup analyses revealed that the beneficial effect of CTR was more pronounced in Asian populations compared with European populations (P for interaction <0.001) and in plate-haptic IOLs compared with C-loop IOLs (P for interaction<0.001). Regarding visual and refractive outcomes, no significant differences were observed between the two groups in UDVA, CDVA, or UNVA (all P>0.05), whereas postoperative RAS was significantly lower in the CTR group (SMD=-0.86, 95%CI:-1.40 to -0.32, P=0.002). No significant differences were found in the incidence of posterior capsule opacification, anterior capsule opacification, or elevated intraocular pressure between the groups (all P>0.05). Conclusion: Co-implantation of a CTR demonstrates good postoperative safety, significantly enhances IOL rotational stability, and effectively reduces postoperative residual astigmatism, though it does not lead to a significant improvement in visual acuity.