Condition category
Eye Diseases
Date applied
22/06/2018
Date assigned
23/06/2018
Last edited
16/07/2018
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Intraocular lenses (IOLs) are implanted inside the eye to replace the eye's natural lens when it is removed during cataract surgery. Trifocal diffractive IOLs have been demonstrated to restore intermediate vision without damaging distance or near vision. This new concept of IOL has confirmed good performance for visual outcomes, patient satisfaction and spectacle independence. However, patients’ corneal astigmatism (imperfection in the curvature of the cornea) is critical to the choice of trifocal diffractive IOL, which is a key factor influencing the visual acuity and refractive outcomes after the operation. Many studies have shown that the location of the corneal incision (cut) has an impact on postoperative corneal astigmatism and higher-order aberrations (HOAs), such as degradation of vision at night, halos and glare. However, there is no research on the effect of incisions on visual outcomes after implantation of trifocal diffractive IOLs. This study aims to evaluate visual acuity, corneal astigmatism and corneal HOAs after implantation of a trifocal diffractive IOL operated with either a corneal steep-axis incision or a 135° incision.

Who can participate?
Patients with cataract or presbyopia suitable for refractive lens exchange, who have pre-existing corneal astigmatism of less than 1.00 D, and who are seeking spectacle independence

What does the study involve?
Participants are randomly allocated to one of two groups: group A are treated with a 2.8 mm clear corneal incision at the steep-axis and group B are treated with a 2.8 mm clear corneal incision at 135°. According to their preoperative corneal astigmatism, groups A and B are separated into two subgroups: A1 (0 ~ 0.50 D), A2 (0.51 ~ 1.00 D), B1 (0 ~ 0.50 D), and B2 (0.51 ~ 1.00 D). Visual acuity, corneal astigmatism and corneal HOAs are followed up for 3 months. Visual outcomes are assessed between group A1 and group B1 and between group A2 and group B2 to evaluate the usability of the intervention.

What are the possible benefits and risks of participating?
After the end of the study the participants are expected to gain high-quality refractive outcomes and spectacle independence. There are no risks associated with the intervention.

Where is the study run from?
The Affiliated Hospital of Qingdao University (China)

When is the study starting and how long is it expected to run for?
December 2015 to March 2018

Who is funding the study?
1. National Natural Science Foundation of China
2. National Natural Science Foundation of Shandong

Who is the main contact?
Dr Shasha Xue
xueshasha1104@126.com

Trial website

Contact information

Type

Public

Primary contact

Dr Shasha Xue

ORCID ID

Contact details

The Affiliated Hospital of Qingdao University
No.16 Jiangsu Road
Shinan District
Qingdao
266000
China
+86 (0)17863961151
xueshasha1104@126.com

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Effect of incision on visual outcomes after implantation of a trifocal diffractive intraocular lens

Acronym

Study hypothesis

Visual outcomes with corneal steep-axis incision are better than 135° incision after implantation of trifocal diffractive intraocular lens (IOL).

Ethics approval

Ethics committee of the Affiliated Hospital of Qingdao University, 30/12/2015, ref: qddxfsyy2614

Study design

interventional randomised controlled study

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet

Condition

Patients undergoing cataract surgery with implantation of a trifocal diffractive IOL

Intervention

This prospective study enrolled patients randomly assigned to different groups. According to preoperative corneal astigmatism, patients were assigned into group A1 (0 ~ 0.50 D) or A2 (0.51 ~ 1.00 D) with a corneal steep-axis incision or group B1 (0 ~ 0.50 D) or B2 (0.51 ~ 1.00 D) with a 135° incision. Visual acuity, corneal astigmatism and corneal higher-order aberrations (HOAs) were followed up for 3 months.

Intervention type

Procedure/Surgery

Phase

Drug names

Primary outcome measure

1. Corneal astigmatism measured with a Galilei device (Galilei G2, Ziemer ophthalmic systems AG, Port, Switzerland) at 1 day, 2 weeks, 1 month, or 3 months postoperatively
2. Uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA) obtained by the standard logarithmic chart at 1 day, 2 weeks, 1 month, or 3 months postoperatively
3. Total corneal wavefront aberration, root mean square value of corneal higher-order aberrations (RMS HOAs), spherical aberration (SA), coma, or trefoil measured with a Galilei device (Galilei G2, Ziemer ophthalmic systems AG, Port, Switzerland) at 1 day, 2 weeks, 1 month, or 3 months postoperatively

Secondary outcome measures

1. The proportion of astigmatic axial length with the rule (WTR) (90°± 30°), against the rule (ATR) (0°to 30°or 150°to 180°), and oblique (30°to 60°or 120°to 150°) at pre operation and 3 months post operation
2. Surgically induced astigmatism (SIA) calculated using Jaffe/Clayman vector analysis at 3 months post operation
3. UDVA and CDVA between the subgroups obtained by the standard logarithmic chart pre operation

Overall trial start date

01/12/2015

Overall trial end date

31/03/2018

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

Patients with cataract or presbyopia suitable for refractive lens exchange seeking spectacle independence who had preexisting corneal astigmatism of less than 1.00 D

Participant type

Patient

Age group

Senior

Gender

Both

Target number of participants

101 eyes of 77 patients undergoing cataract surgery with implantation of a trifocal diffractive IOL (AT LISA tri 839MP, Carl Zeiss Meditec, Germany) were divided into two groups: group A including 49 eyes of 37 patients with a 2.8 mm clear corneal incision at the steep-axis and group B including 52 eyes of 40 patients with a 2.8mm clear corneal incision at 135°. According to the preoperative corneal astigmatism, groups A and B were separated into two subgroups: A1 (0 ~ 0.50 D with 22 eyes), A2 (0.51 ~ 1.00 D with 27 eyes), B1 (0 ~ 0.50 D with 23 eyes), and B2 (0.51 ~ 1.00 D with 29 eyes).

Participant exclusion criteria

Patients with a history of glaucoma, retinal detachment, corneal disease, irregular corneal astigmatism, abnormal iris, macular degeneration or retinopathy, neuro-ophthalmic disease, ocular inflammation, or previous ocular surgery

Recruitment start date

01/01/2016

Recruitment end date

31/12/2017

Locations

Countries of recruitment

China

Trial participating centre

The Affiliated Hospital of Qingdao University
No.16 Jiangsu Road Shinan District
Qingdao
266000
China

Sponsor information

Organisation

The Affiliated Hospital of Qingdao University

Sponsor details

No.16 Jiangsu Road
Shinan District
Qingdao
266000
China

Sponsor type

Hospital/treatment centre

Website

Funders

Funder type

Government

Funder name

National Natural Science Foundation of China (81470609, 81300730)

Alternative name(s)

National Science Foundation of China, Natural Science Foundation of China, NSFC

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government

Location

China

Funder name

National Natural Science Foundation of Shandong (ZR2017BH025)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Planned publication in a high impact peer-reviewed journal.

IPD sharing statement
Data will be available indefinitely at the Data Repository of the Affiliated Hospital of Qingdao University. All of the individual participant data collected during the trial will be shared after deidentification. Participant Information sheet, Study Protocol, Statistical Analysis Plan, Informed Consent Form, and Clinical Study Report will also be available. Data will be available immediately following publication with no end date for anyone who wishes to access the data for any purpose. Anyone who intends to access the datasets could contact Dr Shasha Xue (xueshasha1104@126.com).

Intention to publish date

15/07/2018

Participant level data

Stored in repository

Basic results (scientific)

Publication list

2018 results in: https://www.ncbi.nlm.nih.gov/pubmed/30005634

Publication citations

Additional files

Editorial Notes

16/07/2018: Publication reference added.