1. Maria A Henriquez MD Luis Izquierdo MD Jackeline Parraga MD
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
Jackeline Parraga 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 nasal
3 mm temporal

5. RESULTS Examiner #1 Examiner #2 Mean SD* SD * LOCALIZATION 0 mm
38.78 µm
39.05
3 mm Nasal µm
37.01 µm
47.8
3 mm Temporal µm
40.55 µm
39.83
Table 1. Mean flap thickness at 0 mm, 3 mm nasal y 3 mm temporal points (* standard deviation).

6. Concordance according the intraclass correlation coefficients (ICCs)
The ICC was having GOOD concordance between the measurements.
Concordance according the intraclass correlation coefficients (ICCs)
ICC Value
Concordance
> 0.90
Very goog
Good
Moderate
Medium
< o.30
Bad
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):
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 Dec;46(12):
Kucumen RB et al. AS-OCT as a tool for flap thickness measurement after femtosecond-assisted LASIK. Ophthalmic Surg Lasers Imaging 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 Mar;46(3): 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 May;36(5):810-3.

9. MARIA ALEJANDRA HENRIQUEZ BERTAGGIA
Medical School. ULA Merida. Venezuela. Magnacumlaude.
Opthalmology Residency, 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 Research Department at Oftalmosalud Insitute of Eyes.