Using a capsular tension ring to keep the lens implant centered in people with retinitis pigmentosa who need cataract surgery

Effect of Capsular Tension Ring Implantation on Postoperative IOL Position in Retinitis Pigmentosa Patients With Cataract: a Multi-center, Randomized, Self-controlled Study

This trial will try adding a capsular tension ring to one eye of adults with retinitis pigmentosa undergoing cataract surgery to see if it keeps the implanted lens more centered and reduces vision problems compared with the other eye.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 88 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Zhongshan Ophthalmic Center, Sun Yat-sen University (Academic / other)
• Locations: 3 sites (Guangzhou, Guangdong and 2 other locations)
• Trial ID: NCT07126470 on ClinicalTrials.gov

What this trial studies

Retinitis pigmentosa often causes zonular weakness and capsular changes that increase the risk of intraocular lens (IOL) tilt, decentration, and capsular contraction after cataract surgery. This self-controlled randomized trial will enroll 88 adults with bilateral cataracts and RP, implanting the same monofocal DCB00 IOL in both eyes but adding a capsular tension ring (CTR) to one randomly chosen eye while the fellow eye serves as the control. Outcomes including IOL decentration and tilt measured by anterior segment SS-OCT (CASIA2), visual acuity, and postoperative complications will be recorded at 1 week, 1 month, 3 months, 6 months, and 1 year. Intraindividual comparison aims to clarify whether CTR reduces lens malposition and related complications in this high-risk population.

Who should consider this trial

Good fit: Adults (≥18) with a clinical diagnosis of retinitis pigmentosa and bilateral cataracts appropriate for IOL implantation who can give informed consent and attend scheduled follow-up visits are the intended participants.

Not a fit: Patients with prior intraocular surgery, severe zonular dialysis (>90%) or lens dislocation, significant coexisting ocular disease (such as uveitis or pseudoexfoliation), or severe systemic illness are excluded and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, adding a CTR could keep the lens implant straighter and more stable after cataract surgery, potentially improving vision and reducing complication rates in people with RP.

How similar studies have performed: CTR use is established to stabilize the capsular bag in eyes with zonular weakness, but its specific benefit in retinitis pigmentosa remains controversial and has not been definitively proven.

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.

Where this trial is running

Guangzhou, Guangdong and 2 other locations

• Zhongshan Ophthalmic Center, Sun Yat-sen University — Guangzhou, Guangdong, China (Recruiting)
• Shenzhen Eye Hospital — Shenzhen, Guangdong, China (Not_yet_recruiting)
• Wuhan Aier Eye Hospital — Wuhan, Hubei, China (Not_yet_recruiting)

Study contacts

• Principal investigator: Xuhua Tan, PhD — Zhongshan Ophthalmic Center, Sun Yat-sen University
• Study coordinator: Yuke Pan, Master

Conditions Cataract; Retinitis Pigmentosa