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RecruitingNCT03299530Updated Aug 19, 2026

Accuracy of Corneal Astigmatism in Different Region Modes

An observational study in Astigmatism and Cornea, sponsored by Wenzhou Medical University. Recruiting at 1 site in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-19.

Sponsored by Wenzhou Medical University · Observational

Study type
Observational
Model
Case-only
Time perspective
Cross-sectional
Enrollment
70
Ages
18 Years and older
Sex
All
01

Study summary

To analyze the difference between measured total corneal astigmatism and actual corneal astigmatism under different region modes and optimize the region setting.

02

Conditions studied

  • Astigmatism
  • Cornea

Keywords

  • Corneal Astigmatism
  • Scheimpflug
  • pupil size
  • Toric
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

Patients who received cataract surgery in The Eye Hospital of Wenzhou Medical University

Inclusion criteria

  • Age ≥ 18 years
  • Patients who had received phacoemulsification surgery with or without implantation of toric IOL are with a certain amount of corneal astigmatism.
  • Best corrected visual acuity ≥ 0.66 (20/30 Snellen)

Exclusion criteria

Exclusion Criteria:

  • Corneal diseases or severe irregular astigmatism (e.g., pterygium, keratoconus), existence of corneal opacification;
  • Ocular disease which may affect visual acuity (e.g., glaucoma, uveitis, retinal disease, pathologic myopia);
  • History of ocular surgery or ocular trauma before this cataract surgery;
  • Decentration of IOL > 0.3mm or tilt > 5°
  • Implantation of multifocal IOL
  • history of wearing of rigid contact lens within the past 4 weeks or soft contact lens within 1 week;
04

Study design

Observational model
Case-only
Time perspective
Cross-sectional
Enrollment
70 participants (estimated)
Patient registry
No

Groups and cohorts

  • patients with corneal astigmatism

    Patients who had received phacoemulsification surgery with or without implantation of toric IOL are with a certain amount of corneal astigmatism.

    Other: patients with corneal astigmatism

Interventions

  • Otherpatients with corneal astigmatism

    The total corneal astigmatism, anterior chamber depth, will be measured by a Scheimpflug tomographer. Pupil size will be measured by itrace device and MONCV3 device. Residual astigmatism will be tested by subjective refraction.

05

What researchers measure

Primary outcomes

  1. Vectorial difference

    The vectorial difference between measured corneal astigmatism (under multiple different region mode settings) and actual corneal astigmatism.

    Time frame: ≥1 month after surgery

  2. pupil size

    pupil size of patients in a bright environment measured by itrace device and MONCV3 device

    Time frame: ≥1 month after surgery

  3. pupil size 2

    pupil size of patients measured by Pentacam HR device

    Time frame: ≥1 month after surgery

  4. residual astigmatism

    residual astigmatism tested by subjective refraction

    Time frame: ≥1 month after surgery

  5. total corneal astigmatism

    Total corneal astigmatism measured by a scheimpflug tomographer under different region mode settings.

    Time frame: ≥1 month after surgery

  6. Anterior chamber depth

    The distance between corneal apex and anterior surface of IOL measured by a scheimpflug tomographer

    Time frame: ≥1 month after surgery

  7. actual corneal astigmatism

    actual corneal astigmatism is derived from residual astigmatism at corneal plane and cylindrical power of IOL at corneal plane through Holladay 2 formula.

    Time frame: ≥1 month after surgery

06

Study locations

1 of 1 sites recruiting
  • Eye Hispital of Wenzhou Medical University
    Wenzhou, Zhejiang 325000, China
    Recruiting
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03299530
Lead sponsor
Wenzhou Medical University
Responsible party
A-Yong Yu (Director of the Cataract Clinical Center, Wenzhou Medical University) — Principal investigator
First posted
Oct 3, 2017
Start date
Oct 10, 2017
Primary completion
Jun 10, 2027 (estimated)
Completion
Oct 28, 2027 (estimated)
Last update
Aug 19, 2026

Study contacts

AYong Yu, MD.PhD.
Contact
yaybetter@hotmail.com
+86-0577-88068880
Xu Shao, MD
Contact
564056712@qq.com
AYong Yu, MD.PhD.
principal investigator · Wenzhou Medical University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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