Comparison of In-the-bag Stability Between Single-piece and Three-piece Intraocular Lens

November 18, 2015 updated by: Haotian Lin, Sun Yat-sen University

Comparison of In-the-bag Stability Between Single-piece and Three-piece Intraocular Lens Via Scheimpflug Imaging System

Rapid advances of cataract surgery techniques and intraocular lens (IOL) technology have enabled the transition of cataract surgery from blindness relief to refractive correction. An ideal IOL is the critical component to achieve the refractive target of cataract surgery. Biocompatibility, rate of posterior capsule opacification (PCO) and visual quality have all been suggested as the critical factors of an ideal IOL and widely investigated. Recently, stability of IOL position has also been suggested as one of those critical factors due to its close correlation with postoperative visual function. Data suggests that IOL forward movement of 0.29 mm along the visual axis is associated with -0.4D myopic shift. Wang and colleagues recently reported that 0.5mm decentration of an aspheric IOL could eliminate its aberration-correcting effect. Poor stability could even lead to IOL exchange, an additional surgery that put both surgeons and patients in pain.

As the supporting element of an IOL, the haptics are crucial to keep the IOL in place. Various haptic designs are being compared in terms of position stability of IOLs. Haptic designs of single-piece versus 3-piece are often compared because they are currently the most commonly used types. Single-piece IOLs have soft and broader haptics which are made of the same material as the optic, usually hydrophobic or hydrophilic acrylic, whereas 3-piece IOLs have rigid haptics which are made of poly methyl methacrylate (PMMA). Clinical studies comparing these haptic designs have yielded controversial results regarding their position stability in the capsular bag, which is the most recommended site for IOL fixation in an uneventful cataract surgery.

Study Overview

Status

Status

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

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

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Detailed Description

Rapid advances of cataract surgery techniques and intraocular lens (IOL) technology have enabled the transition of cataract surgery from blindness relief to refractive correction. An ideal IOL is the critical component to achieve the refractive target of cataract surgery. Biocompatibility, rate of posterior capsule opacification (PCO) and visual quality have all been suggested as the critical factors of an ideal IOL and widely investigated. Recently, stability of IOL position has also been suggested as one of those critical factors due to its close correlation with postoperative visual function. Data suggests that IOL forward movement of 0.29 mm along the visual axis is associated with -0.4D myopic shift. Wang and colleagues recently reported that 0.5mm decentration of an aspheric IOL could eliminate its aberration-correcting effect. Poor stability could even lead to IOL exchange, an additional surgery that put both surgeons and patients in pain.

As the supporting element of an IOL, the haptics are crucial to keep the IOL in place. Various haptic designs are being compared in terms of position stability of IOLs. Haptic designs of single-piece versus 3-piece are often compared because they are currently the most commonly used types. Single-piece IOLs have soft and broader haptics which are made of the same material as the optic, usually hydrophobic or hydrophilic acrylic, whereas 3-piece IOLs have rigid haptics which are made of poly methyl methacrylate (PMMA). Clinical studies comparing these haptic designs have yielded controversial results regarding their position stability in the capsular bag, which is the most recommended site for IOL fixation in an uneventful cataract surgery.

Most previous studies measure the IOL position based on Purkinje reflections. The measurement is time-consuming and patients are reluctant to cooperate during image acquisition. Purkinje measurement does not detect anterior chamber depth (ACD) and as such cannot reveal the IOL position along the axis. Clinical Scheimpflug systems based on rotating Scheimpflug imaging, on the other hand, is able to acquire sufficient 3-dimensioinal data points within a reasonably short period, usually seconds. It was shown that these systems are one of the best methods to estimate IOL position. To better compare the intracapsular stability between single-piece and 3-piece IOLs, the investigators measured IOL positions with rotating Scheimpflug imaging systems and tested the visual quality of patients implanted with these IOLs.

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.
65

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

  • China
    • Guangdong
      • Guangzhou, Guangdong, China, 510060
        • Zhognshan Ophthalmic Center, Sun Yat-sen University

Participation Criteria

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Eligibility Criteria

Eligibility Criteria

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Ages Eligible for Study

60 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • diagnosis of bilateral age-related cataract and age between 60 to 85 years

Exclusion Criteria:

  • vision-impairing diseases other than cataract, severe refractive error (Preoperative spherical equivalent of either eye >-6.00D or +5.00D)
  • history of ocular trauma, past refractive surgery or other ophthalmic surgery, capsular or zonular disorders that might affect the post-operative centration of IOLs
  • surgical complications including severe hyphema, iris injury, repeated IOL implantation
  • unable to achieve in-the-bag implantation of IOL, corneal sutures during surgery

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.
Experimental: Single-piece IOL Group
Age-related cataract patients receive in-the-bag implantation of a single-piece IOL
Procedure: Phacomulsification lens removal cataract surgery with single-piece Intraocular lens(IOL) implantation
The phacoemulsification lens removal cataract surgery is performed with single-piece IOL.During Phacoemulsification.
Drug: Subconjunctival dexamethasone
All patients received subconjunctival dexamethasone (2 mg) during surgery. Topical anesthesia, consisting of a single drop of 0.5% proparacaine (Alcaine, Alcon Laboratories), was administered three times at intervals of 5 minutes prior to surgery
Device: Viscoelastic materials
viscoelastic materials are used to protect corneal endothelial cells
Drug: proparacaine
0.5% proparacaine (Alcaine, Alcon Laboratories)
Experimental: Three-piece IOL Group
Age-related cataract patients receive in-the-bag implantation of a three-piece IOL
Drug: Subconjunctival dexamethasone
All patients received subconjunctival dexamethasone (2 mg) during surgery. Topical anesthesia, consisting of a single drop of 0.5% proparacaine (Alcaine, Alcon Laboratories), was administered three times at intervals of 5 minutes prior to surgery
Device: Viscoelastic materials
viscoelastic materials are used to protect corneal endothelial cells
Drug: proparacaine
0.5% proparacaine (Alcaine, Alcon Laboratories)
Procedure: Phacomulsification lens removal cataract surgery with three-piece Intraocular lens(IOL) implantation
The phacoemulsification lens removal cataract surgery is performed with three-piece IOL.During 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
Time Frame
The grade of in-the-bag stability between single-piece intraocular lenses (IOLs) and three-piece intraocular lenses(IOLs)
Time Frame: 3 months after the surgery
3 months after the surgery

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
Time Frame
The visual acuity between single-piece intraocular lenses (IOLs) and three-piece intraocular lenses(IOLs)
Time Frame: 3 months after the surgery
3 months after the surgery

Collaborators and Investigators

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

Sponsor

Sponsor

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Sun Yat-sen University

Publications and helpful links

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General Publications

Helpful Links

Study record dates

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Study Major Dates

Study Start

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.
September 1, 2012

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.
December 1, 2012

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.
December 1, 2012

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).
November 14, 2015

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.
November 18, 2015

First Posted (Estimate)

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.
November 20, 2015

Study Record Updates

Last Update Posted (Estimate)

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.
November 20, 2015

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.
November 18, 2015

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.
November 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • CCPMOH2010-China9

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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