Intraocular pressure rises during laser in situ keratomileusis: Comparison of 3 femtosecond laser platforms

Measurement of the Intraocular Pressure Elevation During Laser-Assisted In Situ Keratomileusis Flap Creation Using a Femtosecond Laser Platform

“…The WaveLight FS200 shares with the IntraLase family the fact that both FS laser platforms use a flat interface for corneal applanation but they differ in the suction mechanism: the FS200 uses a suction ring with an automatic suction pump, whereas the IntraLase uses a manual syringe as a pump, coupled to the suction ring. Interestingly, using the same validated methodology for measuring IOP, as in our study, both the IntraLase 60-kHz 7 and the iFS 150-kHz 14 -the latest generation of the IntraLase family -induce an increase in IOP of nearly 80 to 90 mm Hg during the suctioning phase and 110 to 120 mm Hg during the cutting phase, values that are significantly higher compared to those obtained with the FS200 in the current study. Similar to the IntraLase family, Vetter et al 15 found that the Femto LDV (Ziemer Ophthalmic Systems AG) induce higher suction IOP levels during the corneal flap cut (up to 184 ± 28 mm Hg) in porcine eyes.…”

“…Another important factor to determine is the total time needed to complete the procedure. Interestingly, those platforms that use an independent suction ring spend longer total surgical times (25.10 ± 4.3 seconds with the iFS, 29.5 ± 4.4 seconds with the FS200the current study -and 33.40 ± 3.1 seconds with the Victus), 14 whereas the LenSx showed not only the lowest IOP rise during the cutting phase but also the shortest total surgical time (17.21 ± 0.7 seconds 14 ; see Table 2).…”

“…Our group has previously evaluated the IOP rises when using the Victus and the LenSx for LASIK flap creation 14 and the Catalys for FLACS, 21 using the same methodology as in the current study. As theoretically expected, due to its CI, the LenSx induced a small IOP increase of only 20 ± 5.3 mm Hg during the cutting phase.…”

“…[22][23][24][25] In addition, we also found a clear relationship between the early postoperative flap optical density (OD) (that is an indicator of corneal transparency) and the level of IOP reached during LASIK flap creation. Thus, OD was initially lower in flaps obtained with platforms that induce a high IOP increase 7,14 (i.e. flap OD was 134.5 ± 26.9 gray scale units [GSUs with the IntraLase iFS-150kHz at 1 day postoperatively) 22 compared to those platforms that induce a low IOP increase, 14 such as the LenSx (158.9 ± 18.6 GSU) 22 and FS200 (149.6 ± 28.4 GSU).…”

“…Thus, OD was initially lower in flaps obtained with platforms that induce a high IOP increase 7,14 (i.e. flap OD was 134.5 ± 26.9 gray scale units [GSUs with the IntraLase iFS-150kHz at 1 day postoperatively) 22 compared to those platforms that induce a low IOP increase, 14 such as the LenSx (158.9 ± 18.6 GSU) 22 and FS200 (149.6 ± 28.4 GSU). 23 Fortunately, this transient corneal edema found in the LenSx and the FS200 eyes tend to decrease over time, without affecting the final visual outcomes and the corneal transparency at 3 months postoperatively.…”