Working... Menu

Performance of a Single-piece Toric Acrylic Intraocular Lens

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02155959
Recruitment Status : Completed
First Posted : June 4, 2014
Last Update Posted : June 4, 2014
Information provided by (Responsible Party):
Prim. Prof. Dr. Oliver Findl, MBA, Vienna Institute for Research in Ocular Surgery

Brief Summary:
Abstract Purpose: To evaluate the visual performance and rotational stability of the Tecnis Toric one-piece IOL (AMO, USA) during the first 3 post-operative months Design: Prospective single center study Setting: VIROS - Vienna Institute for Research in Ocular Surgery, a Karl Landsteiner Institute, Hanusch Hospitel, Vienna, Austria Methods: In this prospective study patients with age-related cataract and corneal astigmatism of 1.0 to 3.0 D measured with the IOL-Master 500 (Carl Zeiss Meditec AG, Germany) were included. Pre-operatively, rotating Scheimpflug scans (Pentacam HR, Oculus, Germany) were performed and the cornea was marked in the sitting position at the slit lamp. Patients recieved a single-piece toric hydrophobic acrylic IOL (Tecnis Toric, AMO, USA). Immediately and 3 months after surgery retroillumination photographs were taken to assess the rotational stability of the IOL. Additionally, Autorefraction (Topcon, USA), subjective refraction, uncorrected and distance corrected visual acuity, keratometry, Scheimpflug and ocular wavefront (WASCA, Carl Zeiss Meditec AG, Germany) measurements were performed at the 3 months follow-up.

Condition or disease Intervention/treatment
Cataract Corneal Astigmatism Device: toric intraocular lens

Detailed Description:

Whereas first designs of toric intraocular lenses (toric IOLs) in the early 1990's showed an IOL rotation of more than 30° in one fifth of the patients, modern toric IOLs typically show a mean absolute rotation of 3° to 5°, which would result in a loss of about 10% to 15% of the astigmatism reducing effect of the toric IOL.

Rotational stability of a toric IOL depends on the interaction between the toric IOL and the posterior capsule, whereas misalignment of the toric IOL (defined in this study as the difference between the 3 months postoperatively measured axis of the toric IOL and the intended axis) depends on several factors additionally to rotational stability. Intraoperatively, misalignment may happen due to cyclotorsion of the eye in the lying position or due to peribulbar anaesthesia, and due to imprecision of the surgeon when positioning of the IOL relative to the intended meridian. Both these imprecisions can be dealt with by pre-operative marking of the eye in the sitting position and diligence by the surgeon. Postoperatively, the IOL may rotate because it is undersized for the capsule bag or due to the capsule shrinkage that takes place during fibrotic contraction of the bag in the postoperative period. Since most current IOLs are slightly oversized for the capsule bag, the former is observed rarely and would be more likely in long eyes which tend to have a larger capsule bag diameter. However, capsule bag shrinkage is thought to induce rotation in IOLs with open-loop haptics due to the asymmetry of the haptic design. Typical IOL haptic designs that improve rotational stability are either plate haptic IOLs or special Z-haptic shaped open-loop haptics that attempt to counteract the rotational effect of compression of the shrinking bag. However, both of these IOL designs are thought to have downsides. The former seems to have an increased risk of posterior capsule opacification due to a less effective lens epithelial barrier effect of the optic edge and may also show more rotation in the bag immediately after surgery due to the shorter haptic overall length. The latter IOL design, such as the Z-haptic IOL, is cumbersome to implant and may be prone to damage during implantation.

Aim of this study was to evaluate the rotational stability of a novel single-piece hydrophobic acrylic toric IOL with a C-haptic design.

Layout table for study information
Study Type : Observational
Actual Enrollment : 30 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Rotational Stability of a Single-piece Toric Acrylic Intraocular Lens: a Pilot Study
Study Start Date : March 2011
Actual Primary Completion Date : December 2012
Actual Study Completion Date : December 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Cataract

Group/Cohort Intervention/treatment
one group
one group receiving a toric intraocular lens during cataract surgery.
Device: toric intraocular lens
toric intraocular lens
Other Name: Tecnis toric IOL (Abott Medical Optics, USA)

Primary Outcome Measures :
  1. Rotational stability of the investigated toric lens [ Time Frame: 3 months ]
    Rotation of the investigated intraocular lens using a photograph technique (retroillumination images) immediately after surgery and 3 months later.

Secondary Outcome Measures :
  1. reduction in post-operative higher order aberrations [ Time Frame: 3 months ]
    the investigated intraocular lens was proven to reduce some higher order aberrations (this is a refractive problem caused by the cornea). It was shown that the investigated intraocular lens was reducind higher order aberrations in our study population.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   21 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
patients who were scheduled for cataract surgery and had corneal astigmatism

Inclusion Criteria:

  • corneal astigmatism between 1.0 D and 3.0 D
  • cataract

Exclusion Criteria:

  • irregular astigmatism
  • forme fruste Keratoconus
  • corneal scars
  • phakodonesis
  • pseudoexfoliation syndrome
  • traumatic cataract

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02155959

Sponsors and Collaborators
Prim. Prof. Dr. Oliver Findl, MBA
Layout table for investigator information
Principal Investigator: Oliver Findl, MD, MBA Vienna Institute for Research in Ocular Surgery

Layout table for additonal information
Responsible Party: Prim. Prof. Dr. Oliver Findl, MBA, Prim. Prof. Dr., MBA, Vienna Institute for Research in Ocular Surgery Identifier: NCT02155959     History of Changes
Other Study ID Numbers: toric_rotation_acrylic
First Posted: June 4, 2014    Key Record Dates
Last Update Posted: June 4, 2014
Last Verified: June 2014

Keywords provided by Prim. Prof. Dr. Oliver Findl, MBA, Vienna Institute for Research in Ocular Surgery:

Additional relevant MeSH terms:
Layout table for MeSH terms
Lens Diseases
Eye Diseases
Refractive Errors