A Comprehensive Assessment of Anterior Corneal Power by Different Devices

A Comprehensive Assessment of the Precision and Agreement of Anterior Corneal Power Measurements Obtained Using Different Devices

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01587287

Enrollment

Registered

2012-04-30

Start date

2011-04-30

Completion date

2011-07-31

Last updated

2012-05-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Myopia

Keywords

Anterior corneal power, Placido topographer, Scheimpﬂug, Precision, Agreement

Brief summary

To comprehensively assess the precision and agreement of anterior corneal power measurements using 8 different devices.

Detailed description

Volunteers with healthy corneas will be measured by different instruments to detect their anterior corneal power. Only the right eye of each subject was selected. Measurements were repeated in the second session scheduled 1 to 2 weeks later.

Interventions

DEVICECorneal power measurement

All subjects will be underwent a full ophthalmic examination including vision, auto- and subjective refraction, slit-lamp examination, non-contact tonometry, corneal power measurements with the 8 devices and fundus examination.

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to 55 Years

Healthy volunteers

Yes

Inclusion criteria

* healthy cornea, * best corrected distance visual acuity (BCVA) equal to or better than 20/25, * willing and able to comply with scheduled visits and other study procedures.

Exclusion criteria

* History of refractive surgery or any keratoplasty procedure, * use of contact lenses, * history of corneal dystrophies or degenerative diseases, * history of glaucoma or ocular hypertension, * significant subjective dry eye symptoms, Schirmer I test results of less than 5.0 mm, tear film break-up time shorter than 5 seconds and corneal fluorescein staining positive.

Design outcomes

Primary

Measure	Time frame	Description
Flat corneal power	2 weeks	The intrasession repeatability and intersession reproducibility of ﬂat corneal curvature measurements by using the 8 commercially available instruments.
Steep corneal power	2 weeks	The intrasession repeatability and intersession reproducibility of Steep corneal curvature measurements by using the 8 commercially available instruments.

Secondary

Measure	Time frame	Description
Vector power J0	2 weeks	The intrasession repeatability and intersession reproducibility of vector power J0 measurements by using the 8 commercially available instruments.
Vector power J45	2 weeks	The intrasession repeatability and intersession reproducibility of vector power J45 measurements by using the 8 commercially available instruments.

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 25, 2026