Clinical Ophthalmology (May 2013)

Accuracy and precision of cap thickness in small incision lenticule extraction

  • Ozgurhan EB,
  • Agca A,
  • Bozkurt E,
  • Gencer B,
  • Celik U,
  • Cankaya KI,
  • Demirok A,
  • Yilmaz OF

Journal volume & issue
Vol. 2013, no. default
pp. 923 – 926

Abstract

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Engin Bilge Ozgurhan,1 Alper Agca,1 Ercument Bozkurt,1 Baran Gencer,2 Ugur Celik,1 Kadir İlker Cankaya,1 Ahmet Demirok,1,3 Omer Faruk Yilmaz41Beyoglu Eye Training and Research Hospital, Istanbul, Turkey; 2Ophthalmology Department, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey; 3Department of Ophthalmology, Medeniyet University, Istanbul, Turkey; 4Private practice, Istanbul, TurkeyAims: To report and compare the cap thickness predictability of small incision lenticule extraction (SMILE) and flap thickness of femtosecond laser-assisted in situ keratomileusis (femto-LASIK).Settings and design: Beyoglu Eye Training and Research Hospital, Refractive Surgery Department, Istanbul, Turkey. Retrospective pilot study.Materials and methods: Medical records of patients who had SMILE in one eye and femto-LASIK in the other eye were reviewed. Visante corneal Optical Coherence Tomography (OCT) images at 1 week and 1 month post-surgery were analyzed. Both cap and flap thickness at the temporal edge and the nasal edge were measured and compared to each other.Statistical analyses used: PAWS Statistics 18 and unpaired student t-test were used to compare the groups.Results: The study included 66 eyes of 33 patients (24.7 ± 3.8 years, 20 females and 13 males). Mean flap thickness was 114.88 µm ± 4.96 µm, and mean cap thickness was 114.63 µm ± 5.18 µm. In group 1 (SMILE), cap thickness values were 115.84 µm ± 6.84 µm, 114.75 µm ± 7.36 µm, 113.66 µm ± 6.88 µm, and 114.27 µm ± 6.90 µm in measurement zones 1, 2, 3, and 4, respectively. In group 2 (FemtoLASIK), flap corneal thickness values were 115.96 mmHg ± 7.01 mmHg, 114.72 mmHg ± 7.17 mmHg, 113.54 mmHg ± 6.45 mmHg, and 115.30 mmHg ± 6.64 mmHg in measurement zones 1, 2, 3, and 4, respectively. In both groups, no statistically significant change within the measurement zones was observed.Conclusion: The predictability of cap thickness in SMILE surgery does not differ from the femto-LASIK flaps created using the same femtosecond laser platform.Keywords: SMILE, small incision lenticule extraction