Impact of Capsular Tension Ring on Intraocular Lens Position in Retinitis Pigmentosa Cataract Patients

Sun Yat-sen University

Status: Enrolling

Conditions: Cataract; Retinitis Pigmentosa (RP)

Treatments: Procedure: CTR implantation

Study type: Interventional

Funder types: Other

Identifiers

NCT07126470

2025KYPJ066

Details and patient eligibility

About

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.

Full 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.

Enrollment: 88 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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88 participants in 2 patient groups

Treatment Group: IOL Plus CTR implantation

Experimental group

Description:

Patients will undergo phacoemulsification combined with IOL and CTR implantation

Treatment:

Procedure: CTR implantation

Control Group: IOL implantation Only

No Intervention group

Description:

Patients will undergo phacoemulsification combined with IOL implantation. 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, IOL (J\&J Tecnis DCB00) is implanted in the capsular bag.