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Comparative analysis of corneal measurements obtained from a S cheimpflug camera and an integrated P lacido‐optical coherence tomography device in normal and keratoconic eyes
Author(s) -
Viswanathan Deepa,
Kumar Nikhil L.,
Males John J.,
Graham Stuart L.
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.12622
Subject(s) - keratometer , ophthalmology , optical coherence tomography , medicine , corneal topography , keratoconus , repeatability , cornea , optics , chemistry , physics , chromatography
Purpose To assess the agreement between a S cheimpflug camera ( P entacam) and a combined P lacido‐optical coherence tomography device ( V isante OMNI ) in measuring corneal curvature, thickness and elevation values in normal and keratoconic eyes. Methods Corneal measurements of 110 normal eyes (one eye per subject) and 70 keratoconic eyes were obtained from both devices and compared. Agreement was determined using the B land– A ltman analysis 95% limits of agreement ( L o A ). Results The P entacam measured significantly greater keratometry readings in the flattest ( K 1) and steepest meridians ( K 2) in normal and keratoconic eyes. The 95% L o A in normal eyes were −0.32 to 0.59 dioptres ( D ) ( K 1) and −0.41 to 0.74 D ( K 2). In keratoconic eyes, the 95% L o A were −1.35 to 1.92 D ( K 1) and −1.38 to 1.99 D ( K 2). The P entacam recorded significantly higher central corneal thickness ( CCT ) values in both groups of eyes. The 95% L o A were −4.31 to 39.89 microns ( μ ) and −12.92 to 41.35 μ in normal and keratoconic eyes, respectively. Pentacam anterior and posterior corneal elevations were significantly greater in both groups of eyes. The devices demonstrated excellent repeatability and reproducibility for corneal curvature and thickness but not elevation measurements. Conclusions The P entacam measured significantly greater corneal curvature, thickness and elevation values compared to the V isante OMNI in normal and keratoconic eyes. The devices agree moderately for anterior corneal elevations in normal eyes and do not appear to be interchangeable for corneal measurements in clinical practice.