Abstract
IMPORTANCE: Capsular tension rings (CTRs) can support weak zonules and inhibit capsular shrinkage, thus potentially reducing intraocular lens (IOL) decentration and tilt. However, it has been debated whether CTRs can reduce IOL decentration and tilt in highly myopic eyes and whether CTR implantation is necessary for all highly myopic eyes. OBJECTIVE: To evaluate the influence of CTR implantation on IOL decentration and tilt in highly myopic eyes. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was conducted between November 2021 and September 2023 at the Zhongshan Ophthalmic Center, Guangzhou, China. Patients with cataract and an axial length (AL) of 26 mm or longer were enrolled. INTERVENTIONS: Participants were stratified into 3 groups based on the AL (stratum 1, 26 mm ≤ AL <28 mm; stratum 2, 28 mm ≤ AL <30mm; stratum 3, AL ≥30 mm), and further randomly assigned to the CTR group (a C-loop IOL combined with a CTR) or the control group (only a C-loop IOL) within each stratum. MAIN OUTCOMES AND MEASURES: IOL decentration at 3 months after cataract surgery was evaluated using anterior segment optical coherence tomography. RESULTS: A total of 186 eyes of 186 participants (mean [SD] age, 57.3 [10.9] years; 118 female [63.4%]) were randomized into the CTR group (93 [50%]) or control group (93 [50%]), with 87 eyes (93.6%) and 92 eyes (98.9%) completing follow-up at 3 months, respectively. The CTR group showed smaller IOL decentration (0.19 mm vs 0.23 mm; difference, -0.04 mm; 95% CI, -0.07 to -0.01 mm; P = .02) and tilt at 3 months, and lower proportions of clinically significant IOL decentration (≥0.4 mm) and tilt (≥7°) at 3 months compared with the control group. Similar results were only found in eyes with an AL of 30 mm or longer (IOL decentration: 0.20 mm vs 0.28 mm; difference, -0.08 mm; 95% CI, -0.14 to -0.02 mm; P = .01). Additionally, the CTR group showed a smaller change in IOL decentration from 1 week to 3 months, higher prediction accuracy, and better visual quality and patient satisfaction in this stratum. No differences were observed between the CTR and control groups in eyes with an AL less than 30 mm. CONCLUSIONS AND RELEVANCE: CTR implantation reduced C-loop IOL decentration and tilt, increased position stability, and improved visual quality in eyes with an AL of 30 mm or longer. These findings support use of CTR implantation in eyes with an AL of 30 mm or longer and implanted with C-loop IOLs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05161520.