Study of toric intraocular lens (IOL) versus limbal relaxing incisions in the management of cataract astigmatism

ISRCTN	ISRCTN24411195
DOI	https://doi.org/10.1186/ISRCTN24411195
Secondary identifying numbers	13/SC/0050

Submission date: 12/04/2013
Registration date: 15/05/2013
Last edited: 18/05/2017

Recruitment status: Stopped
Overall study status: Stopped
Condition category: Eye Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English Summary

Background and study aims
The quality of vision following cataract surgery is affected by the clarity of the ocular media (transparent substances of the eye, i.e the cornea, intraocular lens [IOL], lens capsule and vitreous gel), focus (corneal curvature and IOL) and co-morbidity, e.g. retinal or optic nerve disease. One aspect of focussing is astigmatism, where the vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina, and is caused in cataract post-surgical patients by asymmetry of corneal curvature. This study aims to assess the effect of two alternative means of correcting astigmatism to optimise focus. The first is the placement of additional corneal incisions to directly reduce corneal astigmatism and second is the use of toric IOLs which may alternatively be used to compensate for corneal astigmatism.

Who can participate?
Males and females aged over 18 years listed for cataract surgery.

What does the study involve?
The participants are randomly allocated to one of two groups:
Group 1: Corneal Limbal Relaxing Incisions (LRIs). These are paired partial-thickness incisions placed just within the cornea immediately prior to small incision cataract surgery. This technique corrects up to 3D of cylinder, which is the maximum level correctable on the inclusion criteria.
Group 2: IOL. The Tecnis toric IOL is implanted during cataract surgery to correct astigmatism.
The study will be conducted in compliance with the protocol, Good Clinical Practice, and all applicable regulatory requirements.

What are the possible benefits and risks of participating?
The study intervention is a choice between two alternative means of reducing post-operative astigmatism. Additional surgical incisions carry a risk of infection, reduced by the routine use of post-operative antibiotic eyedrops. The corneal incisions may also in the immediate post-operative period give a foreign body sensation in the eye. Toric IOLs may rotate in the eye; if rotation is excessive then surgical repositioning may be required. Both techniques carry the risk of over- or under-correcting astigmatism, such that spectacle correction of vision remains necessary.

Where is the study run from?
Royal Berkshire NHS Foundation Trust (UK).

When is the study starting and how long is it expected to run for?
May 2013 to January 2014

Who is funding the study?
Abbott Medical Optics Inc. (USA)

Who is the main contact?
Mr Martin Leyland

Contact information

Mr Martin Leyland
Scientific

Royal Berkshire NHS Foundation Trust
London Road
Reading
RG1 5AN
United Kingdom

Study information

Study design	Randomised controlled trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Hospital
Study type	Treatment
Participant information sheet	Not available in web format, please use the contact details to request a patient information sheet
Scientific title	Randomised controlled trial of Tecnis 1-piece toric intraocular lens (IOL) versus limbal relaxing incisions in the management of cataract astigmatism
Study hypothesis	Toric IOLs may be an effective alternative to limbal relaxing incisions (LRIs) for the treatment of astigmatism post cataract surgery.
Ethics approval(s)	Berkshire South Central NRES Committee, 05/03/2013, ref: 13/SC/0050
Condition	Cataract surgery
Intervention	Reducing astigmatism by comparing toric IOLs vs limbal relaxing incisions (LRIs). This study is a randomised controlled trial of two techniques to control post-operative astigmatism. Group 1: Corneal Limbal Relaxing Incisions (LRIs). These are paired partial thickness incisions placed just within the cornea immediately prior to small incision cataract surgery. This technique corrects up to 3D of cylinder, which is the maximum level correctable on the inclusion criteria. Group 2: IOL. The Tecnis toric IOL is can be implanted during cataract surgery to correct astigmatism, and is available in cylindrical powers of 1.00, 1.5, 2.25, 3.00 and 4.00 with a spherical diopter range of 5-34 dioptres. Toric IOL biometry calculations using a proprietary algorithm (AMO Abbott Medical Optical), cross-referenced with standard biometry calculation. The study will be conducted in compliance with the protocol, Good Clinical Practice, and all applicable regulatory requirements.
Intervention type	Procedure/Surgery
Primary outcome measure	1. Visual acuity 2. Corneal astigmatism Unaided vision will be measured 2 weeks after the operation Optician sight test will be carried out 6 weeks after the operation
Secondary outcome measures	Visual satisfaction score will be measured 6 weeks after the operation
Overall study start date	01/05/2013
Overall study end date	01/01/2014
Reason abandoned (if study stopped)	Participant recruitment issue

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	40
Participant inclusion criteria	1. Symptomatic cataract 2. Vision 6/12 or worse 3. Corneal astigmatism >0.75D horizontal or >1.25D vertical and (maximum 3.0D) 4. Males and females aged over 18 years
Participant exclusion criteria	1. <18 years of age 2. Astigmatism >3.0D or irregular 3. Dry eye severe enough to affect keratometry despite topical lubricant treatment 4. Ocular co-morbidity
Recruitment start date	01/05/2013
Recruitment end date	01/01/2014

Locations

Countries of recruitment

England
United Kingdom

Study participating centre

Royal Berkshire NHS Foundation Trust

Reading
RG1 5AN
United Kingdom

Sponsor information

Royal Berkshire NHS Foundation Trust (UK)
Hospital/treatment centre

London Road
Reading
RG1 5AN
England
United Kingdom

Website	http://www.royalberkshire.nhs.uk
"ROR"	https://ror.org/034nvrd87

Funders

Funder type

Industry

Abbott Medical Optics Inc. (USA) will provide the toric IOL at the same price as the non-toric IOL

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
Publication and dissemination plan	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
HRA research summary			28/06/2023	No	No

Editorial Notes

18/05/2017: The trial was stopped due to poor recruitment.