Abstract: Objective To evaluate the 5-year or longer clinical safety and efficacy of CTR model capsular tension ring implantation. Design Prospective cohort study. Participants 36 subjects completed 5-year continuous observation, including 18 subjects in the study group and 18 subjects in the control group. The clinical research centers were Zhongshan Ophthalmic Center, Sun Yat-sen University; Department of Ophthalmology, Army Medical Center of PLA, Army Characteristic Medical Center (Daping Hospital) and Eye Hospital; Wenzhou Medical University. Methods The subjects who underwent lens extraction combined with capsular tension ring and intraocular lens implantation and completed 1 year follow-up(monocular enrollment) were observed for more than 5 years. In the early stage, the subjects were randomly divided into two groups, the subjects in study group were implanted with the CTR model capsular tension ring and the subjects in control group were implanted with the TENSIOBAG model capsular tension ring. Main Outcome Measures Uncorrected distance visual acuity(UDVA) (LogMAR), best-corrected distance visual acuity (BCDVA) (LogMAR), spherical equivalent (SE), intraocular pressure (IOP), corneal endothelial cell density, slit lamp examination results, subjective visual evaluation results, hyperopia out of lens rate and overall satisfaction. Results There were no significant differences between the two groups in terms of baseline basic data and ophthalmologic examinations, balanced and comparable. At different visit time points after operation, there was no significant difference in UDVA, BCDVA, and objective SE between the two groups (all P>0.05). At 5 years after operation, UDVA was improved from 0.49±0.41 to 0.20±0.20 in the study group and from 0.52±0.51 to 0.32±0.33 in the control group. The UDVA reached 0.30 or better ratio was 88.89% in the study group, and was 72.22% in the control group; BCDVA was from 0.44±0.37 to 0.09±0.12 in the study group and from 0.34±0.23 to 0.10±0.21 in the control group; the objective SE was from -3.52±8.70 D to -0.70±2.05 D in the study group and from -4.49±7.14 D to -0.51±1.32 D in the control group. There was no significant difference in visual acuity and SE between 5 years or above after operation and other time points after operation in the study group, while the control group fluctuated to a certain extent. At 5 years or above after operation, there was no significant difference in IOP between the two groups (all P>0.05), and there was no significant difference compared with the baseline period (all P>0.05). At 5 years or above after operation, there was no significant difference in corneal endothelial cell density between the two groups (P=0.128). There was no IOL deviation, abnormal position and shrinkage of the capsular bag in two groups. There were no significant differences in slit lamp examination, subjective evaluation of poor visual symptoms, hyperopia out of lens rate and overall satisfaction between the two groups at 5 years or above after operation (all P>0.05). Conclusion Through a small sample size study of 5 years or more after CTR model capsular tension ring implantation, it was found that the long-term visual acuity and SE of the subjects after operation were relatively stable, IOP and corneal endothelial cell density were normal, the subjects complained of no obvious visual adverse symptoms, and the overall satisfaction was high, and has good long-term safety and efficacy. (Ophthalmol CHN, 2022, 31: 423-428)

Key words:  capsular tension ring, cataract