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. 2018 May 17:12:935-942.
doi: 10.2147/OPTH.S164570. eCollection 2018.

Evaluation of femtosecond laser in flap and cap creation in corneal refractive surgery for myopia: a 3-year follow-up

Mohamed Nagy Elmohamady  1 , Walid Abdelghaffar  1 , Ahmed Daifalla  1 , Tamer Salem  1
Affiliations

Evaluation of femtosecond laser in flap and cap creation in corneal refractive surgery for myopia: a 3-year follow-up

Mohamed Nagy Elmohamady et al. Clin Ophthalmol. .

Abstract

Purpose: To evaluate femtosecond laser in flap and cap creation, detect some corneal biomechanical changes, and evaluate dry eye after laser in situ keratomileusis (LASIK), Femto-LASIK, and small incision lenticule extraction (SMILE) with 3-year follow-up.

Patients and methods: Preoperative evaluation taken: full ophthalmic examination, Pentacam, ocular response analyzer, ocular surface disease index (OSDI), and tear breakup time (TBUT). LASIK flap was created using Moria microkeratome in 30 eyes (LASIK group) and using VisuMax femtosecond laser in 38 eyes (FS-LASIK group) and SMILE was done by VisuMax in 35 eyes (SMILE group). Postoperative evaluation: anterior segment optical coherence tomography to measure flap and cap thickness, ocular response analyzer to measure corneal hysteresis (CH) and corneal resistance factor (CRF), OSDI, and TBUT at 1, 3, 6, 12, 24, and 36 months after surgery.

Results: This study included 103 eyes of 103 patients. The mean deviation of central cap or flap thickness from intended was statistically higher in the LASIK group (P<0.001). Both CH and CRF showed significant reduction postoperatively but were significantly higher in the SMILE group during follow up (P<0.05). The mean OSDI scores were significantly elevated in all groups postoperatively (P<0.01) but were significantly lower in the SMILE group 3 months postoperatively (P<0.05). The mean TBUT was significantly decreased in all groups postoperatively (P<0.01) but was significantly higher in the SMILE group 6 months postoperatively (P<0.05).

Conclusion: Femtosecond laser is more accurate than microkeratomes. CH and CRF changes were least after SMILE. The three procedures led to significant dryness but for shorter duration with SMILE.

Keywords: LASIK; SMILE; corneal biomechanics; dry eye; femtosecond laser; myopia.

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Conflict of interest statement

Disclosure The authors report no conflicts of interest in this work.

Figures

Figure 1
Figure 1
Preoperative (pre-op) and postoperative (post-op) corneal hysteresis (CH) changes in the three groups. Abbreviations: LASIK, laser in situ keratomileusis; FS-LASIK, femtosecond laser-LASIK; SMILE, small incision lenticule extraction.
Figure 2
Figure 2
Preoperative (pre-op) and postoperative (post-op) corneal resistance factor (CRF) changes in the three groups. Abbreviations: LASIK, laser in situ keratomileusis; FS-LASIK, femtosecond laser-LASIK; SMILE, small incision lenticule extraction.
Figure 3
Figure 3
Preoperative (pre-op) and postoperative (post-op) ocular surface disease index (OSDI) changes in the three groups. Abbreviations: LASIK, laser in situ keratomileusis; FS-LASIK, femtosecond laser-LASIK; SMILE, small incision lenticule extraction.
Figure 4
Figure 4
Preoperative (pre-op) and postoperative (post-op) tear breakup time (TBUT) changes in the three groups. Abbreviations: LASIK, laser in situ keratomileusis; FS-LASIK, femtosecond laser-LASIK; SMILE, small incision lenticule extraction.
See this image and copyright information in PMC

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