Impact of Capsular Tension Ring on Intraocular Lens Position in Retinitis Pigmentosa Cataract Patients
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: CTR implantation.
- Who it may be relevant to
- Registry conditions: Cataract, Retinitis Pigmentosa (RP). Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- China
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Effect of Capsular Tension Ring Implantation on Postoperative IOL Position in Retinitis Pigmentosa Patients With Cataract: a Multi-center, Randomized, Self-controlled Study
Overview
This is a self-controlled randomized clinical trial to investigate the effect of capsular tension ring (CTR) implantation on intraocular lens (IOL) position in cataract patients with retinitis pigmentosa(RP). Each patient will receive CTR implantation in one eye, with the fellow eye serving as control. Postoperative outcomes, including visual acuity, IOL position, and postoperative complications will be compared between eyes.
Detailed description
Patients with retinitis pigmentosa (RP) have a higher risk of developing cataracts, often accompanied by abnormalities such as zonular laxity and vitreous liquefaction, which increases the risk of intraocular lens (IOL) tilt, decentration, and capsular contraction after surgery. The capsular tension ring (CTR) can support the zonules and maintain the stability of the capsular bag, but its effect in RP patients remains controversial.
In this self-controlled clinical trial, we are going to recruit 88 RP patients scheduled for bilateral cataract surgery. Both eyes receive a monofocal DCB00 IOL, while only on eye receives an additional CTR. Follow up visits take place 1 week, 1 month, 3 months, 6 months, and 1 year postoperatively. At the follow up visits, IOL decentration and tilt (determined by anterior segment SS-OCT Casia 2), visual acuity, and postoperative complications will be compared intraindividually at different timepoints.
Interventions
- Procedure CTR implantation
Device: CTR (275001G, OPHTEC BV, Netherlands) All patients undergo uneventful phacoemulsification by a 2.2 mm temporal transparent corneal incision using Centurion Vision System (Alcon Laboratories, Fort Worth, TX, USA). After the nucleus and cortex are removed, a capsular tension ring is implanted in the capsular bag and then IOL (J\&J Tecnis DCB00) is implanted.
Primary outcome measures
- IOL dencentration [Time frame: 3 months after surgery]
Secondary outcome measures (4)
- IOL dencentration [Time frame: Baseline (before surgery), 1 week, 1 month, 6 months, 1 year after surgery]
- IOL tilt [Time frame: Baseline (before surgery), 1 week, 1 month, 3 months, 6 months, 1 year after surgery]
- BCVA [Time frame: Baseline (before surgery), 1 week, 1 month, 3 months, 6 months, 1 year after surgery]
- Postoperative complications [Time frame: 1 week, 1 month, 3 months, 6 months, 1 year after surgery]
Eligibility criteria
Inclusion criteria
- Age ≥ 18 years.
- Clinical diagnosis of retinitis pigmentosa (RP).
- Bilateral cataract meeting the indications for IOL implantation.
- Willingness to participate in the study and provision of signed informed consent.
Exclusion criteria
- History of intraocular surgery.
- Severe zonular weakness (e.g., zonular dialysis >90°, lens subluxation/dislocation)
- Other ocular comorbidity: such as pseudoexfoliation syndrome, ocular trauma, corneal dystrophies, uveitis, etc.
- Severe systemic diseases: such as severe hypertension, diabetes, heart disease, Alzheimer's, Parkinson, etc.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Single blind
- Primary purpose
- Treatment
Study locations
China · 3 centers
- Zhongshan Ophthalmic Center, Sun Yat-sen University — Guangzhou
- Shenzhen Eye Hospital — Shenzhen
- Wuhan Aier Eye Hospital — Wuhan
Identifiers
NCT: NCT07126470 · 2025KYPJ066