Accuracy of Corneal Astigmatism in Different Region Modes
Study Details
Study Description
Brief Summary
To analyze the difference between measured total corneal astigmatism and actual corneal astigmatism under different region modes and optimize the region setting.
Condition or Disease | Intervention/Treatment | Phase |
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Study Design
Arms and Interventions
Arm | Intervention/Treatment |
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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.
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Outcome Measures
Primary Outcome Measures
- 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
- 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
- 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.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Age ≥ 18 years
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Patients who had received phacoemulsification surgery with or without implantation of toric IOL are with a certain amount of corneal astigmatism.
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Best corrected visual acuity ≥ 0.66 (20/30 Snellen)
Exclusion Criteria:
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Corneal diseases or severe irregular astigmatism (e.g., pterygium, keratoconus), existence of corneal opacification;
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Ocular disease which may affect visual acuity (e.g., glaucoma, uveitis, retinal disease, pathologic myopia);
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History of ocular surgery or ocular trauma before this cataract surgery;
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Decentration of IOL > 0.3mm or tilt > 5°
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Implantation of multifocal IOL
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history of wearing of rigid contact lens within the past 4 weeks or soft contact lens within 1 week;
Contacts and Locations
Locations
Site | City | State | Country | Postal Code | |
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1 | Eye Hispital of Wenzhou Medical University | Wenzhou | Zhejiang | China | 325000 |
Sponsors and Collaborators
- Wenzhou Medical University
Investigators
- Principal Investigator: AYong Yu, MD.PhD., Wenzhou Medical University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 2017ASTIGMATISM REGIONS