Comparative Study of Corneal Thickness before and after FemtoLasik Surgery with Pentacam® AXL and Ultrasound Device (Tomey SP-100)

Main Article Content

E. Pateras
E. Kontogeorgou


Aims: The purpose of our research is to evaluate corneal thickness, pre-operative and post-operatively after FemtoLasik surgery, using “Pentacam® AXL” and Ultrasound device. To evaluate the correlation of the two devices and their interchangeability.

Sample and Study Design: Our data includes 70 eyes of patients, age 19- 59 years, who undergone Lasik surgery for myopia. The data concerned pre-operative and post-operative central corneal pachymetry using Ultrasound pachymeter (Tomey SP-100) and “Pentacam® AXL”.

Methodology - Place and Duration of Study: University of West Attica Dept Biomedical Science Course Optics & Optometry in collaboration with Private Ophthalmology Clinic “Athens Opthalologiko” during the period between May 2018 until September 2018. In this study, a comparison of data taken with Pentacam and Ultrasound was performed concerning central corneal thickness before and after FemtoLasik to evaluate the correlation of these devices. All the FemtoLasik surgeries were performed by the same experienced surgeon in order to ensure good repeatability of surgical procedures and all the patients selected had healthy eyes with no other ophthalmic pathology or systemic disease and myopia ranging from -1.00 to 9.25 Diopters. All patients were measured one month after FemtoLasik having achieved 6/6 visual acuity.

Results: Central corneal thickness before FemtoLasik measured by ultrasound device had an arithmetic mean value of 552.43 μm ± SD 26.95. The thickness preoperatively with “Pentacam” had an arithmetic mean value of 556.26 μm ± SD 27.82. The corneal thickness after Lasik measured by ultrasound device had an arithmetic mean value of 493.21μm ± SD 36.30, while for “Pentacam” the arithmetic mean value was 499.07μm ± SD 36.17. The two devices correlate strongly (0.9218 and 0.9986 respectively with significant level P<0,0001)

Conclusion: Our conclusions after statistical analysis are that Ultrasound pachymetry and “Pentacam” topography correlated strong.

Central corneal thickness, refractive surgery, Lasik, depth of ablation, residual stromal bed, “Pentacam”, ultrasound, corneal flap

Article Details

How to Cite
Pateras, E., & Kontogeorgou, E. (2020). Comparative Study of Corneal Thickness before and after FemtoLasik Surgery with Pentacam® AXL and Ultrasound Device (Tomey SP-100). Ophthalmology Research: An International Journal, 13(3), 20-27.
Original Research Article


Usama Fares, Mouhamed Ali Al-Aqaba, Ahmad Muneer Otri, Harminder S Dua. A review of refractive surgery. European Ophthalmic Review. 2011;5(1): 50-5 Available:

Gimbel HV, Levy SG. Indications, results, and complications of LASIK. Current Opinion in Ophthalmology. 1998;9(4):3-8.

DOI: 10.1097/00055735-199808000-00002

Azar TD. Refractive surgery. Mosby El sevier, China; 2007.

ISBN: 978-0-323-03599-6

Azar TD, Koch DD. LASIK. Marcel Deckner inc, USA; 2002.

ISBN: 0-8247-0797-4

Han T, Xu Y, Han X, et al. Three-year outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia and myopic astigmatism. Br J Ophthalmol. 2019;103:565–568.

Timothy Todd, et al. LASIK flap stability after severe ocular injury. American Journal of Ophthalmology Case Reports. 2020;18:1-4.


Alió J, Muftuoglu O, Ortiz D, et al. Ten-year follow-up of laser in situ keratomileusis for myopia of up to – 10 diopters. Am J Ophthalmol. 2008;145: 46–54.

Amano S, Honda N, Amano Y, Yamagami S, Miyai T, Samejima T, et al. Comparison of central corneal thickness measurements by rotating Scheimpflug camera, ultrasonic pachymetry, and scanning-slit corneal topography. Ophthalmology. 2006;113(6):937–41.

DOI: 10.1016/j.ophtha.2006.01.063

Rainer G, Petternel V, Findl O, et al. Comparison of ultrasound pachymetry and partial coherence interferometry in the measurement of central corneal thickness. J Cataract Refract Surg. 2002; 28(12):2142–2145.

Ho T, Cheng AC, Rao SK, Lau S, Leung CK, Lam DS. Central corneal thickness measurements using Orbscan II, Visante, ultrasound, and Pentacam pachymetry after laser in situ keratomileusis for myopia. J Cataract Refract Surg. 2007; 33(7):1177–82.

DOI: 10.1016/j.jcrs.2007.03.028

Hashemi H, Mehravaran S. Central corneal thickness measurement with Pentacam, Orbscan II, and ultrasound devices before and after laser refractive surgery for myopia. J Cataract Refract Surg. 2007;33(10):1701–7.

DOI: 10.1016/j.jcrs.2007.05.040

Sadoughi MM, Einollahi B, Einollahi N, Rezaei J, Roshandel D, Feizi S. Measurement of Central Corneal Thickness Using Ultrasound Pachymetry and Orbscan II in Normal Eyes. J Ophthalmic Vis Res. 2015;10(1):4–9.

DOI: 10.4103/2008-322X.156084

Ciolino JB, Khachikian SS, Belin MW. Comparison of corneal thickness measurements by ultrasound and Scheimpflug photography in eyes that have undergone laser in situ keratomileusis. Am J Ophthalmol. 2008; 145(1):75–80.

DOI: 10.1016/j.ajo.2007.08.026

Sedaghat MR, Daneshvar R, Kargozar A, Derakhshan A, Daraei M. Comparison of central corneal thickness measurement using ultrasonic pachymetry, rotating Scheimpflug camera, and scanning-slit topography. Am J Ophthalmol. 2010; 150(6):780–9.

DOI: 10.1016/j.ajo.2010.06.013

Al-Mezaine HS, Al-Amro SA, Kangave D, Al-Obeidan S, Al-Jubair KM. Comparison of central corneal thickness measurements using Pentacam and ultrasonic pachymetry in post-LASIK eyes for myopia. Eur J Ophthal. 2010;20(5): 852–7.

Tai LY, Khaw KW, Ng CM, Subrayan V. Central corneal thickness measurements with different imaging devices and ultrasound pachymetry. Cornea. 2013; 32(6):766–1.

DOI: 10.1097/ICO.0b013e318269938d

Mohammad Reza Djodeyre, et al. Long-term evaluation of eyes with central corneal thickness <400 μm following laser in situ keratomileusis. Clin Ophthalmol. 2016;10:535–540.

DOI: 10.2147/OPTH.S100690

Sherif Emerah, Ehab EL Zakzouk, Mohamed Farag. Comparison of Central Corneal Thickness Measurements by Pentacam and Ultrasound Pachymetry in Normal Myopic Patients. Electron Physician. 2016;8(12): 3441–3444.