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

NCT ID: NCT02609997

Last Updated: 2015-11-20

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

65 participants

Study Classification

INTERVENTIONAL

Study Start Date

2012-09-30

Study Completion Date

2012-12-31

Brief Summary

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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.

Detailed Description

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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.

Conditions

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Cataract

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

SINGLE

Outcome Assessors

Study Groups

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Single-piece IOL Group

Age-related cataract patients receive in-the-bag implantation of a single-piece IOL

Group Type EXPERIMENTAL

Phacomulsification lens removal cataract surgery with single-piece Intraocular lens(IOL) implantation

Intervention Type PROCEDURE

The phacoemulsification lens removal cataract surgery is performed with single-piece IOL.During Phacoemulsification.

Subconjunctival dexamethasone

Intervention Type DRUG

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

Viscoelastic materials

Intervention Type DEVICE

viscoelastic materials are used to protect corneal endothelial cells

proparacaine

Intervention Type DRUG

0.5% proparacaine (Alcaine, Alcon Laboratories)

Three-piece IOL Group

Age-related cataract patients receive in-the-bag implantation of a three-piece IOL

Group Type EXPERIMENTAL

Phacomulsification lens removal cataract surgery with three-piece Intraocular lens(IOL) implantation

Intervention Type PROCEDURE

The phacoemulsification lens removal cataract surgery is performed with three-piece IOL.During Phacoemulsification.

Subconjunctival dexamethasone

Intervention Type DRUG

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

Viscoelastic materials

Intervention Type DEVICE

viscoelastic materials are used to protect corneal endothelial cells

proparacaine

Intervention Type DRUG

0.5% proparacaine (Alcaine, Alcon Laboratories)

Interventions

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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.

Intervention Type 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.

Intervention Type PROCEDURE

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

Intervention Type DRUG

Viscoelastic materials

viscoelastic materials are used to protect corneal endothelial cells

Intervention Type DEVICE

proparacaine

0.5% proparacaine (Alcaine, Alcon Laboratories)

Intervention Type DRUG

Eligibility Criteria

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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
Minimum Eligible Age

60 Years

Maximum Eligible Age

85 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Sun Yat-sen University

OTHER

Sponsor Role lead

Responsible Party

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Haotian Lin

Principal Investigator, Home for Cataract Children, Zhongshan Ophthalmic Center

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Haotian Lin, M.D., Ph.D

Role: PRINCIPAL_INVESTIGATOR

Zhongshan Ophthalmic Center, Sun Yat-sen University

Yizhi Liu, M.D., Ph.D

Role: STUDY_CHAIR

Zhongshan Ophthalmic Center, Sun Yat-sen University

Weirong Chen, M.D.

Role: STUDY_DIRECTOR

Zhongshan Ophthalmic Center, Sun Yat-sen University

Locations

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Zhognshan Ophthalmic Center, Sun Yat-sen University

Guangzhou, Guangdong, China

Site Status

Countries

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China

References

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Korynta J, Bok J, Cendelin J. Changes in refraction induced by change in intraocular lens position. J Refract Corneal Surg. 1994 Sep-Oct;10(5):556-64.

Reference Type BACKGROUND
PMID: 7530106 (View on PubMed)

Wang L, Koch DD. Effect of decentration of wavefront-corrected intraocular lenses on the higher-order aberrations of the eye. Arch Ophthalmol. 2005 Sep;123(9):1226-30. doi: 10.1001/archopht.123.9.1226.

Reference Type BACKGROUND
PMID: 16157803 (View on PubMed)

Rosales P, Marcos S. Phakometry and lens tilt and decentration using a custom-developed Purkinje imaging apparatus: validation and measurements. J Opt Soc Am A Opt Image Sci Vis. 2006 Mar;23(3):509-20. doi: 10.1364/josaa.23.000509.

Reference Type BACKGROUND
PMID: 16539046 (View on PubMed)

de Castro A, Rosales P, Marcos S. Tilt and decentration of intraocular lenses in vivo from Purkinje and Scheimpflug imaging. Validation study. J Cataract Refract Surg. 2007 Mar;33(3):418-29. doi: 10.1016/j.jcrs.2006.10.054.

Reference Type BACKGROUND
PMID: 17321392 (View on PubMed)

Zhong X, Long E, Chen W, Xiang W, Liu Z, Chen H, Chen J, Lin Z, Lin H, Chen W. Comparisons of the in-the-bag stabilities of single-piece and three-piece intraocular lenses for age-related cataract patients: a randomized controlled trial. BMC Ophthalmol. 2016 Jul 8;16:100. doi: 10.1186/s12886-016-0283-4.

Reference Type DERIVED
PMID: 27392024 (View on PubMed)

Related Links

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http://www.gzzoc.com/

Description Home page of Zhongshan Ophthalmic Center

Other Identifiers

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CCPMOH2010-China9

Identifier Type: -

Identifier Source: org_study_id