Capsular Tension Ring With Hydrophilic Versus Hydrophobic Intraocular Lenses (CTR-IOL-3ARM)

September 21, 2026 updated by: Ehab Mohamed Elsayed Mohamed Saad, Benha University

Outcomes of Hydrophilic Intraocular Lens Implantation With and Without a Capsular Tension Ring Versus Hydrophobic Intraocular Lens Implantation Alone: A Randomized Controlled Trial

This study compares three approaches to cataract surgery. Cataract surgery involves removing the eye's cloudy natural lens and replacing it with an artificial intraocular lens (IOL) to restore clear vision. IOLs are made from different materials, most commonly a "hydrophilic" (water-attracting) acrylic or a "hydrophobic" (water-repelling) acrylic. Hydrophilic lenses are generally easier and less expensive to use, but have been linked in past research to a higher chance of the lens capsule becoming cloudy again after surgery (posterior capsule opacification, or PCO), sometimes requiring a follow-up laser treatment. Hydrophobic lenses tend to have lower rates of this problem but can cost more.

A capsular tension ring (CTR) is a small flexible ring that can be placed inside the eye at the time of surgery to help hold the lens capsule in a stable, round shape. This study asks whether adding a CTR when a hydrophilic lens is used can reduce the disadvantages usually seen with that lens material.

600 adult patients (ages 50-80) undergoing cataract surgery at three hospitals in Egypt were randomly assigned to one of three groups: (1) a hydrophilic lens plus a CTR, (2) a hydrophobic lens alone (the common comparison approach), or (3) a hydrophilic lens alone without a CTR. Patients were followed for 24 months, and researchers compared vision, glasses prescription accuracy, lens position, capsule clouding, need for laser treatment, and surgical complications between the groups.

The results showed that adding a CTR to a hydrophilic lens produced results very similar to using a hydrophobic lens alone. In contrast, using a hydrophilic lens without a CTR resulted in worse vision, less accurate glasses prescriptions, more lens shifting or tilting, more capsule clouding, a higher need for laser treatment, and more complications compared with the hydrophobic lens. These findings suggest that adding a CTR may be a simple, low-cost way to improve outcomes when a hydrophilic lens is used for cataract surgery.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Detailed Description

Background and rationale: Phacoemulsification with intraocular lens (IOL) implantation is the standard treatment for age-related cataract. IOL material (hydrophilic versus hydrophobic acrylic) is a recognized determinant of long-term capsular biocompatibility, with hydrophobic acrylic lenses generally associated with lower rates of posterior capsule opacification (PCO) and reduced need for neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy compared with hydrophilic acrylic lenses. Capsular tension rings (CTRs) are polymethyl methacrylate devices that stabilize the capsular bag equator and have been proposed to mitigate capsular contraction, lens decentration, and PCO, independent of IOL material. Prior comparative work has generally examined either IOL material effects or CTR effects in isolation, or has compared a composite intervention (hydrophilic IOL plus CTR) against a hydrophobic IOL alone, without a design capable of isolating the CTR's independent contribution.

Objectives: To compare visual, refractive, anatomical (IOL position and posterior capsule opacification), and safety outcomes among three approaches to routine cataract surgery: (1) hydrophilic acrylic IOL implantation combined with a CTR (Group A); (2) hydrophobic acrylic IOL implantation alone (Group B); and (3) hydrophilic acrylic IOL implantation alone, without a CTR (Group C). The inclusion of Group C, using the same hydrophilic IOL model as Group A but without CTR insertion, was designed specifically to allow assessment of the CTR's independent contribution when compared against Group A, in addition to the material-based comparisons of Groups A and C against Group B.

Design: Prospective, randomized, parallel-group, three-arm controlled trial conducted at three tertiary ophthalmology centers in Egypt (Zagazig University Hospital, Benha University Hospital, and Al-Azhar University Hospital). Eligible adults aged 50-80 years with visually significant age-related cataract (LOCS III grade >=3) were randomized 1:1:1 using a computer-generated allocation sequence, with allocation concealment via sealed opaque envelopes opened intraoperatively. Outcome assessors and data analysts were blinded to treatment allocation; operating surgeons were not blinded due to the nature of the intervention.

Interventions: All participants underwent standardized phacoemulsification via a 2.2 mm clear corneal incision with a ~5.5 mm continuous curvilinear capsulorhexis. Group A received a hydrophilic acrylic IOL (Eyecryl, Biotech Healthcare, India) plus a polymethyl methacrylate CTR (Auroring CTR 11, Aurolab, India). Group B received a hydrophobic acrylic IOL (AcrySof IQ, Alcon Laboratories, USA) without a CTR. Group C received the same hydrophilic acrylic IOL as Group A, without CTR insertion.

Outcomes: Primary outcomes were best-corrected visual acuity (logMAR) and manifest spherical equivalent refractive error at 24 months, with longitudinal assessment at 1, 3, 6, 12, 18, and 24 months. Secondary outcomes included posterior capsule opacification grade (slit-lamp retroillumination, graded per Aslam et al.), Nd:YAG capsulotomy rate, IOL centration and tilt (anterior segment optical coherence tomography), and intraoperative and postoperative complications (posterior capsule rupture, zonular dialysis, vitreous loss, iris trauma, cystoid macular edema, intraocular pressure elevation, corneal edema, and endophthalmitis).

Follow-up: Scheduled visits at day 1, week 1, and months 1, 3, 6, 12, 18, and 24 postoperatively, with the 24-month visit representing the final prespecified assessment.

Statistical analysis: Continuous variables were compared across groups using one-way ANOVA or Kruskal-Wallis testing as appropriate, with post-hoc pairwise comparisons for Group A vs. Group B and Group C vs. Group B. Categorical variables were compared using chi-square or Fisher's exact test. Repeated-measures ANOVA assessed longitudinal group x time interactions for visual and refractive outcomes.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
600

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
    • Benha
      • Banhā, Benha, Egypt, 13111
        • Benha University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age 50-80 years
  • Visually significant age-related cataract, defined as nuclear opacity grade >=3 according to the Lens Opacities Classification System III (LOCS III), graded preoperatively under standardized mydriasis via slit-lamp biomicroscopy
  • Clear cornea
  • Adequate pupillary dilation
  • Anatomically normal capsular bag with no evidence of zonular weakness
  • No ocular comorbidities expected to affect visual or refractive outcomes

Exclusion Criteria:

  • Previous intraocular surgery
  • Ocular trauma
  • Pseudoexfoliation syndrome
  • Posterior polar cataract
  • Zonular instability
  • Complicated cataract
  • Active intraocular inflammation
  • Retinal or optic nerve pathology
  • Anticipated need for additional capsular support devices beyond the study protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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Phacoemulsification with implantation of a hydrophilic acrylic intraocular lens (Eyecryl, Biotech Healthcare, India) combined with insertion of a polymethyl methacrylate capsular tension ring (Auroring CTR 11, Aurolab, India).
Device: Hydrophilic acrylic intraocular lens (Eyecryl)

Foldable hydrophilic acrylic intraocular lens implanted in the capsular bag following phacoemulsification.

Device: Capsular tension ring (Auroring CTR 11)

Polymethyl methacrylate capsular tension ring (overall diameter 13.0 mm, compressed diameter 11.0 mm) inserted into the capsular bag to distribute equatorial zonular forces and maintain capsular bag contour.
Active Comparator: Group B: Hydrophobic IOL alone

Phacoemulsification with implantation of a hydrophobic acrylic intraocular lens (AcrySof IQ, Alcon Laboratories, USA), without a capsular tension ring.
Device: Hydrophobic acrylic intraocular lens (AcrySof IQ)

Foldable hydrophobic acrylic intraocular lens implanted in the capsular bag following phacoemulsification.
Experimental: Group C: Hydrophilic IOL alone

Phacoemulsification with implantation of the same hydrophilic acrylic intraocular lens used in Group A (Eyecryl, Biotech Healthcare, India), without capsular tension ring insertion.
Device: Hydrophilic acrylic intraocular lens (Eyecryl)

Foldable hydrophilic acrylic intraocular lens implanted in the capsular bag following phacoemulsification.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Best-corrected visual acuity (BCVA)
Time Frame: 24 months postoperatively

Best-corrected visual acuity measured in logMAR units, assessed longitudinally at 1, 3, 6, 12, 18, and 24 months, with between-group comparison at 24 months as the primary efficacy endpoint.
24 months postoperatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Manifest spherical equivalent refractive error
Time Frame: 24 months postoperatively

Manifest spherical equivalent refractive error (diopters), assessed longitudinally at 1, 3, 6, 12, 18, and 24 months, with between-group comparison at 24 months as the primary efficacy endpoint. Proportion of eyes within +/-0.5 D and +/-1.0 D of target refraction was also assessed at 24 months.
24 months postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Benha University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 15, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 15, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 21, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 21, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 25, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 25, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ZU-BU-AU-CTR-IOL-3ARM-2023

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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