Corneal diameter measurements by corneal topography and angle-to-angle measurements by optical coherence tomography: Evaluation of equivalence

Abstract

The WTW and ATA distance measurements were not equivalent and thus are not interchangeable. There was no linear model for an accurate prediction of the ATA from the WTW.

Intraobserver and interobserver repeatability of ocular components measurement in cataract eyes using a new optical low coherence reflectometer

“…Third generation formulas for IOL calculation use WW as a parameter in determining the IOL power [12], while the selection of angle supported and posterior chamber phakic intraocular lenses (pIOL) is based on calculations using the WW [13]. Angle-supported pIOLs have been associated with complications which arise from poor pIOL sizing.…”

Intrasubject repeatability of corneal morphology measurements obtained with a new Scheimpflug photography–based system

“…In addition to pachymetry, excellent consistency was also obtained for ACD and WTW parameters, with repeatability comparable to that reported for several other devices. 5,6,9,20,25,26 In summary, this new Sirius topography system based on the combination of a rotating Scheimpflug camera and a Placido disk provided repeatable anterior and posterior curvature and shape-factor measurements as well as pachymetry measurements using a fast, noninvasive technique. In addition, the device provided WTW and ACD measurements with excellent intrasubject repeatability.…”

A review of corneal diameter, curvature and thickness values and influencing factors*

“…Routinely, in optometric practice, CD is often measured with a hand-held millimeter ruler, a ruler combined with a magnifier or use of the slit-lamp graticule 11 . But CD can be more accurately measured with the instruments such as an autorefractometer (for example, the Canon Autoref R-1), corneal topographers such as the Orbscan II system and via optical coherence tomograph 12 . The horizontal diameter of the cornea on average is 10 mm in infants and 11 mm in adults while the vertical diameter is usually 11 mm in infants and 12 mm in adults 11,13 .…”