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International Ophthalmology
Published in: International Ophthalmology 4/2018

01-08-2018 | Original Paper

Validation of Fourier analysis of videokeratographic data

Authors: Haris Sideroudi, Georgios Labiris, Fienke Ditzel, Efi Tsaragli, Kimonas Georgatzoglou, Haralampos Siganos, Vassilios Kozobolis

Published in: International Ophthalmology | Issue 4/2018

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Abstract

Purpose

The aim was to assess the repeatability of Fourier transfom analysis of videokeratographic data using Pentacam in normal (CG), keratoconic (KC) and post-CXL (CXL) corneas.

Methods

This was a prospective, clinic-based, observational study. One randomly selected eye from all study participants was included in the analysis: 62 normal eyes (CG group), 33 keratoconus eyes (KC group), while 34 eyes, which had already received CXL treatment, formed the CXL group. Fourier analysis of keratometric data were obtained using Pentacam, by two different operators within each of two sessions. Precision, repeatability and Intraclass Correlation Coefficient (ICC), were calculated for evaluating intrassesion and intersession repeatability for the following parameters: Spherical Component (SphRmin, SphEcc), Maximum Decentration (Max Dec), Regular Astigmatism, and Irregularitiy (Irr). Bland–Altman analysis was used for assessing interobserver repeatability.

Results

All parameters were presented to be repeatable, reliable and reproductible in all groups. Best intrasession and intersession repeatability and reliability were detected for parameters SphRmin, SphEcc and Max Dec parameters for both operators using ICC (intrasession: ICC > 98%, intersession: ICC > 94.7%) and within subject standard deviation. Best precision and lowest range of agreement was found for the SphRmin parameter (CG: 0.05, KC: 0.16, and CXL: 0.2) in all groups, while the lowest repeatability, reliability and reproducibility was detected for the Irr parameter.

Conclusions

The Pentacam system provides accurate measurements of Fourier tranform keratometric data. A single Pentacam scan will be sufficient for most clinical applications.
Literature
1.
Kennedy RH, Bourne WM, Dyer JA (1986) A 48-year clinical and epidemiologic study of keratoconus. Am J Ophthalmol 101:267–273CrossRefPubMed
2.
3.
Wilson SE, Klyce SD (1994) Screening for corneal topographic abnormalities before refractive surgery. Ophthalmology 101:145–152
4.
Nesburn A, Bahri S, Salz J, Rabinowitz YS, Maguen E, Hofbauer J, Berlin M, Macy JI (1995) Keratoconus detected by videokeratography in candidates for photorefractive keratectomy. J Refract Surg 11:194–201PubMed
5.
Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, Shin JA, Sterling JL, Wagner H, Gordon MO (1998) Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci 39:2537–2546PubMed
6.
Spoerl E, Huhle M, Seiler T (1998) Induction of cross-links in corneal tissue. Exp Eye Res 66:97–103CrossRefPubMed
7.
Wollensak G, Spoerl E, Seiler T (2003) Riboflavin/ultraviolet-A–induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 135:620–627CrossRefPubMed
8.
Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, Shin JA, Sterling JL, Wagner H, Gordon MO (2010) Anterior chamber characteristics of keratoconus assessed by rotating Scheimpflug imaging. J Cataract Refract Surg 36:1101–1106CrossRef
9.
Piñero DP, Alió JL, Alesón A, Escaf Vergara M, Miranda M (2010) Corneal volume, pachymetry, and correlation of anterior and posterior corneal shape in subclinical and different stages of clinical keratoconus. J Cataract Refract Surg 36:814–825CrossRefPubMed
10.
Raasch TW (1992) Quantitative model of corneal astigmatism from topographic data. In: OSA Technical Digest Series, vol 3. Noninvasive Assessment of the Visual System. Washington: Optical Society of America, pp 24–27
11.
Hjortdal JO, Erdmann L, Bek T (1995) Fourier analysis of videokeratographic data. Ophthalm Physiol Opt 15:171–185
12.
Wyzinski I (1990) Escalation of keratospeak: regular and irregular astigmatism. Refract Corneal Surg 6:23–31
13.
Oshika T, Tanabe T, Tomidokoro A, Amano S (2002) Progression of keratoconus assessed by Fourier analysis of videokeratography data. Ophthalmology 109:339–342CrossRefPubMed
14.
Suzuki M, Amano S, Honda N, Usui T, Yamagami S, Oshika T (2007) Longitudinal changes in corneal irregular astigmatism and visual acuity in eyes with keratoconus. Jpn J Ophthalmol 51:265–269CrossRefPubMed
15.
Sideroudi H, Labiris G, Georgatzoglou K, Ditzel F, Kozobolis V (2016) Fourier analysis of videokeratography data: clinical usefulness in stage I and subclinical keratoconus. J Cataract Refract Surg 42:731–737CrossRefPubMed
16.
Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310CrossRefPubMed
17.
18.
19.
BlandJM AltmanDG (1999) Measuring agreement in method comparison studies. Stat Methods Med Res 8:135–160CrossRef
20.
McAlinden C, Khadka J, Pesudovs K (2011) A comprehensive evaluation of the precision (repeatability and reproducibility) of the Oculus Pentacam HR. Invest Ophthalmol Vis Sci 52:7731–7737CrossRefPubMed
21.
Shankar H, Taranath D, Santhirathelagan CT, Pesudovs K (2008) Anterior segment biometry with the Pentacam: comprehensive assessment of repeatability of automated measurements. J Cataract Refract Surg 34:103–113CrossRefPubMed
22.
Hernández-Camarena JC, Chirinos-Saldaña P, Navas A, Ramirez-Miranda A, de la Mota A, Jimenez-Corona A, Graue-Hernindez EO (2014) Repeatability, reproducibility, and agreement between three different Scheimpflug systems in measuring corneal and anterior segment biometry. J Refract Surg 30:616–621CrossRefPubMed
23.
Sideroudi H, Labiris G, Giarmoulakis A, Bougatsou N, Mikropoulos D, Kozobolis V (2013) Repeatability, reliability and reproducibility of posterior curvature and wavefront aberrations in keratoconic and cross-linked corneas. Clin Exp Optom 96:547–556CrossRefPubMed
24.
Labiris G, Giarmoukakis A, Sideroudi H, Bougatsou P, Lazaridis I, Kozobolis VP (2012) Variability in Scheimpflug image-derived posterior elevation measurements in keratoconus and collagen-crosslinked corneas. J Cataract Refract Surg 38:1616–1625CrossRefPubMed
25.
Labiris G, Giarmoukakis A, Rampotas A, Symeou M, Bougatsou P, Sideroudi H, Kozobolis VP (2015) Variability of different reference bodies in normal, keratoconus, and collagen crosslinked corneas. Eur J Ophthalmol 25:468–473CrossRefPubMed
Metadata
Title
Validation of Fourier analysis of videokeratographic data
Authors
Haris Sideroudi
Georgios Labiris
Fienke Ditzel
Efi Tsaragli
Kimonas Georgatzoglou
Haralampos Siganos
Vassilios Kozobolis
Publication date
01-08-2018
Publisher
Springer Netherlands
Published in
International Ophthalmology / Issue 4/2018
Print ISSN: 0165-5701
Electronic ISSN: 1573-2630
DOI
https://doi.org/10.1007/s10792-017-0602-7

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