Maria A Henriquez MD Luis Izquierdo MD Jackeline Parraga MD

1. Reproducibility and repeatability of corneal flap thickness measured by anterior segment optical coherence tomography The authors have no financial interest in the subject matter of this e-poster Maria A Henriquez MD Luis Izquierdo MD JackelineParraga MD

2. PURPOSE • To evaluate the interexaminer reproducibility and intraexaminer repeatability in the measured of the flap thickness obtained by anterior segment optical coherence tomography (AS-OCT).

3. METHODS • This prospective, randomized study included 128 eyes that underwent LASIK procedure. • 3 months after an anterior segment OCT was performed. • 2 different examiner performed the measurement at 0 mm, 3 mm nasal and 3 mm temporal in a high resolution corneal at the axis of 0° to 180°. • 3 times for each examiner the measurement was done. • The repeatability and reproducibility of the measurements were evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method.

4. AS-OCT scan with measurement of the flap thickness at 3 points. Center 3 mm temporal 3 mm nasal

5. RESULTS Table 1. Mean flap thickness at 0 mm, 3 mm nasal y 3 mm temporal points (* standard deviation).

6. The ICC was 0.75 having GOOD concordance between the measurements. Concordance according the intraclass correlation coefficients (ICCs) ICC: 0.75

7. CONCLUSIONS • Measurement of the flap thickness performed with the AS-OCT showed good repeatability and reproducibility, showing that this device it is accuracy in the preoperative evaluation of the patients before LASIK enhancement.

8. REFERENCES • Xu Y, Zhou X, Wang L, Xu H. A morphological study of corneal flap after thin-flap laser-assisted in situ keratomileusis by anterior segment optical coherence tomography. J Int Med Res. 2010;38(6):1952-60 • Zhang QW, et al. Analysis of flap thickness created with mechanical microkeratome in LASIK by using anterior segment optical coherence tomography. Zhonghua Yan Ke Za Zhi. 2010 Dec;46(12):1104-1109. • Kucumen RB et al. AS-OCT as a tool for flap thickness measurement after femtosecond-assisted LASIK. Ophthalmic Surg Lasers Imaging. 2011 Jan 1;42(1):31-6. • Yu ZQ, et al. Analysis of flap thickness by anterior segment optical coherence tomography in different flap preparation styles of excimer laser surgery. Zhonghua Yan Ke Za Zhi. 2010 Mar;46(3):203-8. Chinese • Bansal AS, Doherty T, Randleman JB, Stulting RD. Influence of flap thickness on visual and refractive outcomes after laser in situ keratomileusis performed with a mechanical keratome. J Cataract Refract Surg. 2010 May;36(5):810-3.

9. MARIA ALEJANDRA HENRIQUEZ BERTAGGIA • Medical School. ULA Merida. Venezuela. Magnacumlaude. • OpthalmologyResidency, Universidad Nacional Federico Villarreal.Peru. • Master in Ophthalmology. Universidad de Salta. Argentina. • PhD in Medicine. USMP Lima Peru. . • Medical Director of OFTALMOSALUD Institute of eyes. Lima- Peru. • Chief of ResearchDepartment at OftalmosaludInsitute of Eyes.