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NCT Number: NCT03299530

Accuracy of Corneal Astigmatism in Different Region Modes

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

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Key information

Conditions

Astigmatism Cornea Corneal Diseases Eye Diseases Refractive Errors

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Eye Hispital of Wenzhou Medical University

Wenzhou, Zhejiang, 325000, China

Location status: Recruiting

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

  • 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;

Treatment and study plan

patients with corneal astigmatism

Other

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.

Primary outcomes

  1. Vectorial difference

    Time frame: ≥1 month after surgery

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

  2. pupil size

    Time frame: ≥1 month after surgery

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

  3. pupil size 2

    Time frame: ≥1 month after surgery

    pupil size of patients measured by Pentacam HR device

  4. residual astigmatism

    Time frame: ≥1 month after surgery

    residual astigmatism tested by subjective refraction

  5. total corneal astigmatism

    Time frame: ≥1 month after surgery

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

  6. Anterior chamber depth

    Time frame: ≥1 month after surgery

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

  7. actual corneal astigmatism

    Time frame: ≥1 month after surgery

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

Study contacts

Contact information is provided by the study sponsor or research team.

AYong Yu, MD.PhD.

CONTACT

[email protected]

+86-0577-88068880

Xu Shao, MD

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

Wenzhou Medical University

Other

Registry information

Important dates

Study start
2017
Primary completion
2026
Study completion
2026
First posted
Oct 3, 2017
Registry last updated
Jul 23, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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