Clinical trial NCT01587287: A Comprehensive Assessment of Anterior Corneal Power by Different Devices
Official title: A Comprehensive Assessment of the Precision and Agreement of Anterior Corneal Power Measurements Obtained Using Different Devices
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Myopia
Keywords: Anterior corneal power
Placido topographer
Scheimpﬂug
Precision
Agreement
Lead sponsor: Wenzhou Medical University
Sponsor class: OTHER
First posted: 2012-04-30
Enrollment: 35
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The present study's definitions of reproducibility, repeatability and agreement were based on those adopted by the British Standards Institute and the International Organization for Standardization.

Corneal curvature measurement provides crucial information for calculating intraocular lens power,screening and managing corneal refractive surgeries and corneal disease.

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, at almost the same time as the first session, by the same examiner using the same protocol.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Flat corneal power
timeFrame: 2 weeks
measure: Steep corneal power
timeFrame: 2 weeks
Secondary outcomes:
measure: Vector power J0
timeFrame: 2 weeks
measure: Vector power J45
timeFrame: 2 weeks
Other outcomes:
Locations:
city: Wenzhou
country: China
facility: Wenzhou Medical College
state: Zhejiang
Study officials:
affiliation: Eye Hospital, Wenzhou Medical College, China
name: Yifang Feng, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wang Q, Savini G, Hoffer KJ, Xu Z, Feng Y, Wen D, Hua Y, Yang F, Pan C, Huang J. A comprehensive assessment of the precision and agreement of anterior corneal power measurements obtained using 8 different devices. PLoS One. 2012;7(9):e45607. doi: 10.1371/journal.pone.0045607. Epub 2012 Sep 25.