Validation of Fourier Analysis of Videokeratographic Data

Overview

Journal Int Ophthalmol

Specialty Ophthalmology

Date 2017 Jun 17

PMID 28620708

Citations 3

Authors

Haris Sideroudi

Georgios Labiris

Fienke Ditzel

Efi Tsaragli

Kimonas Georgatzoglou

Haralampos Siganos

Vassilios Kozobolis

Affiliations

Soon will be listed here.

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.

Citing Articles

Fourier analysis of corneal irregular astigmatism after small-incision lenticule extraction and transepithelial photorefractive keratectomy: A comparative study.

Ning J, Zhang L Medicine (Baltimore). 2024; 103(9):e37340.

PMID: 38428861 PMC: 10906594. DOI: 10.1097/MD.0000000000037340.

Fourier analysis of corneal Scheimpflug imaging: clinical use in keratoconus.

Akincioglu D, Ozge G, Ayyildiz O, Gokce G, Karaca U, Mutlu F Int J Ophthalmol. 2021; 14(12):1963-1969.

PMID: 34926215 PMC: 8640755. DOI: 10.18240/ijo.2021.12.23.

Fourier Analysis of Keratometric Data in Epithelium Removal versus Epithelial Disruption Corneal Cross-linking.

Bamdad S, Zaheryani S, Mohaghegh S, Shirvani M J Ophthalmic Vis Res. 2020; 15(1):16-23.

PMID: 32095204 PMC: 7001009. DOI: 10.18502/jovr.v15i1.5934.

References

Bland J, Altman D . Measurement error and correlation coefficients. BMJ. 1996; 313(7048):41-2. PMC: 2351452. DOI: 10.1136/bmj.313.7048.41. View

Sideroudi H, Labiris G, Giarmoulakis A, Bougatsou N, Mikropoulos D, Kozobolis V . Repeatability, reliability and reproducibility of posterior curvature and wavefront aberrations in keratoconic and cross-linked corneas. Clin Exp Optom. 2013; 96(6):547-56. DOI: 10.1111/cxo.12044. View

Shankar H, Taranath D, Santhirathelagan C, Pesudovs K . Anterior segment biometry with the Pentacam: comprehensive assessment of repeatability of automated measurements. J Cataract Refract Surg. 2008; 34(1):103-13. DOI: 10.1016/j.jcrs.2007.09.013. View

Bland J, Altman D . Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986; 1(8476):307-10. View

Nesburn A, Bahri S, Salz J, Rabinowitz Y, Maguen E, Hofbauer J . Keratoconus detected by videokeratography in candidates for photorefractive keratectomy. J Refract Surg. 1995; 11(3):194-201. View

Labiris G, Giarmoukakis A, Sideroudi H, Bougatsou P, Lazaridis I, Kozobolis V . Variability in Scheimpflug image-derived posterior elevation measurements in keratoconus and collagen-crosslinked corneas. J Cataract Refract Surg. 2012; 38(9):1616-25. DOI: 10.1016/j.jcrs.2012.04.039. View

Suzuki M, Amano S, Honda N, Usui T, Yamagami S, Oshika T . Longitudinal changes in corneal irregular astigmatism and visual acuity in eyes with keratoconus. Jpn J Ophthalmol. 2007; 51(4):265-9. DOI: 10.1007/s10384-007-0453-2. View

Wyzinski P . Escalation of keratospeak: regular and irregular astigmatism. Refract Corneal Surg. 1990; 6(3):231. View

Bland J, Altman D . Measurement error. BMJ. 1996; 313(7059):744. PMC: 2352101. DOI: 10.1136/bmj.313.7059.744. View

10.

Hernandez-Camarena J, Chirinos-Saldana P, Navas A, Ramirez-Miranda A, de la Mota A, Jimenez-Corona A . Repeatability, reproducibility, and agreement between three different Scheimpflug systems in measuring corneal and anterior segment biometry. J Refract Surg. 2014; 30(9):616-21. DOI: 10.3928/1081597X-20140815-02. View

11.

Bland J, Altman D . Measuring agreement in method comparison studies. Stat Methods Med Res. 1999; 8(2):135-60. DOI: 10.1177/096228029900800204. View

12.

Wilson S, Klyce S . Screening for corneal topographic abnormalities before refractive surgery. Ophthalmology. 1994; 101(1):147-52. DOI: 10.1016/s0161-6420(94)31372-8. View

13.

Rabinowitz Y . Keratoconus. Surv Ophthalmol. 1998; 42(4):297-319. DOI: 10.1016/s0039-6257(97)00119-7. View

14.

Sideroudi H, Labiris G, Georgatzoglou K, Ditzel F, Siganos C, Kozobolis V . Fourier analysis of videokeratography data: Clinical usefulness in grade I and subclinical keratoconus. J Cataract Refract Surg. 2016; 42(5):731-7. DOI: 10.1016/j.jcrs.2016.01.049. View

15.

Pinero D, Alio J, Aleson A, Escaf Vergara M, Miranda M . Corneal volume, pachymetry, and correlation of anterior and posterior corneal shape in subclinical and different stages of clinical keratoconus. J Cataract Refract Surg. 2010; 36(5):814-25. DOI: 10.1016/j.jcrs.2009.11.012. View

16.

Spoerl E, Huhle M, Seiler T . Induction of cross-links in corneal tissue. Exp Eye Res. 1998; 66(1):97-103. DOI: 10.1006/exer.1997.0410. View

17.

Wollensak G, Spoerl E, Seiler T . Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol. 2003; 135(5):620-7. DOI: 10.1016/s0002-9394(02)02220-1. View

18.

Oshika T, Tanabe T, Tomidokoro A, Amano S . Progression of keratoconus assessed by fourier analysis of videokeratography data. Ophthalmology. 2002; 109(2):339-42. DOI: 10.1016/s0161-6420(01)00903-4. View

19.

Labiris G, Giarmoukakis A, Rampotas A, Symeou M, Bougatsou P, Sideroudi H . Variability of different reference bodies in normal, keratoconus, and collagen crosslinked corneas. Eur J Ophthalmol. 2015; 25(6):468-73. DOI: 10.5301/ejo.5000621. View

20.

Zadnik K, Barr J, Edrington T, Everett D, Jameson M, McMahon T . Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998; 39(13):2537-46. View