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

ISRCTN ISRCTN10086721
DOI https://doi.org/10.1186/ISRCTN10086721
Secondary identifying numbers N/A
Submission date
22/06/2018
Registration date
23/06/2018
Last edited
16/07/2018
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Eye Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

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

Contact information

Dr Shasha Xue
Public

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

Phone +86 (0)17863961151
Email xueshasha1104@126.com

Study information

Study designinterventional randomised controlled study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details to request a patient information sheet
Scientific titleEffect of incision on visual outcomes after implantation of a trifocal diffractive intraocular lens
Study objectivesVisual outcomes with corneal steep-axis incision are better than 135° incision after implantation of trifocal diffractive intraocular lens (IOL).
Ethics approval(s)Ethics committee of the Affiliated Hospital of Qingdao University, 30/12/2015, ref: qddxfsyy2614
Health condition(s) or problem(s) studiedPatients undergoing cataract surgery with implantation of a trifocal diffractive IOL
InterventionThis 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 typeProcedure/Surgery
Primary outcome measure1. 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 measures1. 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 study start date01/12/2015
Completion date31/03/2018

Eligibility

Participant type(s)Patient
Age groupSenior
SexBoth
Target number of participants101 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).
Key inclusion criteriaPatients with cataract or presbyopia suitable for refractive lens exchange seeking spectacle independence who had preexisting corneal astigmatism of less than 1.00 D
Key exclusion criteriaPatients 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
Date of first enrolment01/01/2016
Date of final enrolment31/12/2017

Locations

Countries of recruitment

  • China

Study participating centre

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

Sponsor information

The Affiliated Hospital of Qingdao University
Hospital/treatment centre

No.16 Jiangsu Road
Shinan District
Qingdao
266000
China

ROR logo "ROR" https://ror.org/026e9yy16

Funders

Funder type

Government

National Natural Science Foundation of China (81470609, 81300730)
Government organisation / National government
Alternative name(s)
Chinese National Science Foundation, Natural Science Foundation of China, National Science Foundation of China, NNSF of China, NSF of China, 国家自然科学基金委员会, National Nature Science Foundation of China, Guójiā Zìrán Kēxué Jījīn Wěiyuánhuì, NSFC, NNSF, NNSFC
Location
China
National Natural Science Foundation of Shandong (ZR2017BH025)

No information available

Results and Publications

Intention to publish date15/07/2018
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryStored in repository
Publication and dissemination planPlanned publication in a high impact peer-reviewed journal.
IPD sharing planData 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).

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 13/07/2018 Yes No

Editorial Notes

16/07/2018: Publication reference added.