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

Summary

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.

Conditions

• Cataract

Interventions

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.

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.

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)

Sponsors & Collaborators

• Sun Yat-sen University

  lead OTHER

Principal Investigators

• Haotian Lin, M.D., Ph.D · Zhongshan Ophthalmic Center, Sun Yat-sen University

• Yizhi Liu, M.D., Ph.D · Zhongshan Ophthalmic Center, Sun Yat-sen University

• Weirong Chen, M.D. · Zhongshan Ophthalmic Center, Sun Yat-sen University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

60 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2012-09-30

Primary Completion

2012-12-31

Completion

2012-12-31

Countries

• China

Study Locations