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.

Study Overview

• Status: Recruiting
• Conditions: Astigmatism; Cornea
• Intervention / Treatment: Other: patients with corneal astigmatism

• Study Type: Observational
• Enrollment (Estimated): 70

Contacts and Locations

• Study Contact: Name: AYong Yu, MD.PhD.; Phone Number: +86-0577-88068880; Email: yaybetter@hotmail.com
• Study Contact Backup: Name: Xu Shao, MD; Email: 564056712@qq.com

Study Locations

• China
  • Zhejiang
    • Wenzhou, Zhejiang, China, 325000
      • Recruiting
      • Eye Hispital of Wenzhou Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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

Description

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;

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vectorial difference	The vectorial difference between measured corneal astigmatism (under multiple different region mode settings) and actual corneal astigmatism.	≥1 month after surgery
pupil size	pupil size of patients in a bright environment measured by itrace device and MONCV3 device	≥1 month after surgery
pupil size 2	pupil size of patients measured by Pentacam HR device	≥1 month after surgery
residual astigmatism	residual astigmatism tested by subjective refraction	≥1 month after surgery
total corneal astigmatism	Total corneal astigmatism measured by a scheimpflug tomographer under different region mode settings.	≥1 month after surgery
Anterior chamber depth	The distance between corneal apex and anterior surface of IOL measured by a scheimpflug tomographer	≥1 month after surgery
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.	≥1 month after surgery

Collaborators and Investigators

• Sponsor: Wenzhou Medical University
• Investigators: Principal Investigator: AYong Yu, MD.PhD., Wenzhou Medical University

Study record dates

Study Major Dates

• Study Start (Actual): October 10, 2017
• Primary Completion (Estimated): June 10, 2024
• Study Completion (Estimated): October 28, 2024

Study Registration Dates

• First Submitted: September 27, 2017
• First Submitted That Met QC Criteria: September 27, 2017
• First Posted (Actual): October 3, 2017

Study Record Updates

• Last Update Posted (Estimated): December 7, 2023
• Last Update Submitted That Met QC Criteria: December 6, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: pupil size; Toric; Scheimpflug; Corneal Astigmatism
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Astigmatism
• Other Study ID Numbers: 2017ASTIGMATISM REGIONS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No