Accuracy of Corneal Astigmatism in Different Region Modes

Recruiting

• Conditions: Cornea; Astigmatism
• Interventions: Other: patients with corneal astigmatism

• Registration Number: NCT03299530
• Lead Sponsor: Wenzhou Medical University

Brief Summary

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

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2017-09-27
• Study First Submitted QC: 2017-09-27
• Study First Posted: 2017-10-03
• Study Start: 2017-10-10
• Status Verified: 2024-07
• Last Update Submitted: 2024-07-22
• Last Update Posted: 2024-07-23
• Primary Completion: 2026-06-10
• Study Completion: 2026-10-28

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 70

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 & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
patients with corneal astigmatism	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.

Primary Outcome Measures

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

Trial Locations

Locations (1)

Eye Hispital of Wenzhou Medical University; 🇨🇳 Wenzhou, Zhejiang, China