Assessing the Astigmatism Reducing Effect With Toric IOLs in Eyeswith Low Astigmatism (Low Asti)

Comparison of the astigmatism reducing effect of a toric IOL with a non toric IOL in eyes with low corneal astigmatism.

Study Overview

• Status: Unknown
• Conditions: Cataract; Astigmatism
• Intervention / Treatment: Procedure: toric intraocular lens; Procedure: non toric intraocular lens

Detailed Description

With increasing demands of patients concerning refractive outcome after cataract surgery, toric intraocular lenses (IOLs) that correct corneal astigmatism have been introduced more widely to cataract surgery. Originally, toric IOLs were used mainly for patients with high degrees of astigmatism. Since a couple of years, toric IOLs are available from numerous manufacturers to correct moderate amounts of astigmatism which are much more prevalent with about 8% having a corneal astigmatism of 2.0D or more in the cataract population. 5Using toric IOLs for these eyes results in less spectacle dependence of patients due to the astigmatic correction. Other astigmatism reducing techniques, such as peripheral corneal relaxing incisions and opposite clear corneal incisions were shown to be less predictable. Although the use of toric IOLs became the gold standard to correct corneal astigmatism during cataract surgery , there is still uncertainty, if low astigmatism should be corrected. Visser et al. showed that moderate astigmatism of than 1.5D should be corrected for monofocal IOLs and Hayashi showed that remaining astigmatism of 1.0D already decreases visual quality in eyes with multifocal IOLs. Although correction of low corneal astigmatism appears to be beneficial, some hurdles have to be taken into account. In eyes with low corneal astigmatism the accuracy of measuring the astigmatism meridian is relatively low. Furthermore, different corneal measurement techniques are not always comparable and it is difficult to know, which device shows the correct amount of astigmatism. Additionally, the correction of the spherical equivalent is of high importance, as a refractive surprise will also attenuate the astigmatism reducing effect of the toric IOL. Aim of this study is to assess, if toric IOLs are useful in patients with low amounts of corneal astigmatism and to quantify the sources of error in toric IOL power calculation.

• Study Type: Interventional
• Enrollment (Anticipated): 25
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Julius Hienert, MD; Phone Number: +43 01 91021 57564; Email: j.hienert@viros.at
• Study Contact Backup: Name: Nino Hirnschall, MD; Phone Number: +43 01 91021 57564; Email: nino.hirnschall@googlemail.com

Study Locations

• Austria
  • Vienna, Austria, 1140
    • Recruiting
    • Vienna Institute for Research in Ocular Surgery (VIROS)
    • Contact: Julius Hienert, MD; Phone Number: 01 90121-57564; Email: j.hienert@viros.at
    • Contact: Nino Hirnschall, MD; Phone Number: 01 90121-57564; Email: nino.hirnschall@wgkk.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 100 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• cataract
• Age 21 and older
• Regular corneal astigmatism 0.5D up to 1.5 D and difference between eyes not more than 0.75D
• written informed consent prior to surgery

Exclusion Criteria:

• relevant other ophthalmic diseases such as: pseudoexfoliation, glaucoma, traumatic cataract corneal scars, and other co-morbidity that could affect capsule bag stability ( e.g. Marfan syndrome)
• Irregular corneal astigmatism on corneal topography
• In case of pregnancy (pregnancy test will be taken preoperatively in women of reproductive age)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Toric intraocular lens (IOL); toric intraocular lens for low astigmatism correction	Procedure: toric intraocular lens; cataract surgery with implantation of an toric intraocular lens
SHAM_COMPARATOR: Non toric intraocular lens (IOL); non toric intraocular lens	Procedure: non toric intraocular lens; cataract surgery with implantation of a non toric intraocular lens

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Subjective refraction to detect remaining astigmatism (in Diopters) between both groups	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biometrical measurement of axial length (in mm), anterior chamber depth (in mm), corneal astigmatism (radii and axial degrees)		12 months
Purkinjemeter measurement of Tilt (in degrees) and Decentration (in degrees) of the intraocular lens		12 months
Wavefront analysis of high order aberrations (root mean square, in microns)		12 months
Questionnaire to asses patients subjective satisfaction with visual outcome	In the questionnaire the patient has to choose if different tasks (e.g. reading, driving, watching TV) are easier for him/ her with the right eye, the left eye, or if there is no difference between both eyes	12 months

Collaborators and Investigators

• Sponsor: Prim. Prof. Dr. Oliver Findl, MBA

Study record dates

Study Major Dates

• Study Start (ACTUAL): May 2, 2018
• Primary Completion (ANTICIPATED): May 2, 2020
• Study Completion (ANTICIPATED): August 1, 2020

Study Registration Dates

• First Submitted: April 30, 2018
• First Submitted That Met QC Criteria: May 15, 2018
• First Posted (ACTUAL): May 29, 2018

Study Record Updates

• Last Update Posted (ACTUAL): October 2, 2019
• Last Update Submitted That Met QC Criteria: October 1, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Keywords: Cataract; Low Astigmatism
• Additional Relevant MeSH Terms: Eye Diseases; Lens Diseases; Refractive Errors; Cataract; Astigmatism
• Other Study ID Numbers: Low Asti

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No