Copenhagen 2016 Registration Programme Exhibitor Information Virtual Exhibition Satellite Meetings Glaucoma Day 2016 Hotel Star Alliance

10 - 14 Sept. 2016, Bella Center, Copenhagen, Denmark

This Meeting has been awarded 27 CME credits


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New technique to reduce incidence of opaque bubble layer formation (OBL) during LASIK flap creation using VisuMax femtosecond laser

Poster Details

First Author: D. Hamilton UNITED STATES

Co Author(s):    N. Wu                    

Abstract Details


To identify risk factors for OBL formation and to compare the incidence of OBL using a new technique versus the original technique for LASIK flap creation using the VisuMax laser.


UCLA Laser Refractive Center (Academic Center), Stein/Doheny Eye Institute, Los Angeles, CA


Retrospective study examining videos of flap creation using VisuMax to identify flaps in which OBL occurred. Group 1: Eyes where OBL occurred using original technique. Group 2: Eyes where OBL did not occur using original technique. Pre-operative measurements including simKs, WTW, pachymetry, patient age/gender, amount of correction, flap parameters, energy setting and corneal resistance factor were analyzed to identify parameters with statistical difference between Groups 1 and 2. Group 3: Eyes in which a new technique was used for LASIK flap creation (larger flap diameter). Incidence of OBL was compared between original technique and new technique.


OBL incidence is significantly lower with the new technique 7.6% (7 of 92 eyes) than with the old technique 28.8% (34 of 118 eyes) (Fisher exact, P = 0.0009). Factors identified with a significant difference between eyes with and without OBL using the old technique are: pachymetry (OBL: 561.2, no OBL: 549.6, P=0.0132), WTW (OBL: 11.6, no OBL: 11.9 , P=0.0048), CRF (OBL: 10.4, no OBL: 9.6, P= 0.0329), K average (OBL: 44.4, no OBL: 43.6, P=0.0550), K2-K1 (OBL: 0.8, no OBL: 1.0, P=0.0472), Axis (refraction) (OBL: 57.6, no OBL: 93.5, P=0.0550).


Steeper, thicker, denser and smaller corneas could be risk factors for OBL using the original technique for flap creation. A new technique for flap creation which allows for a larger flap diameter is associated with significantly lower risk of OBL formation, even in eyes with significant risk factors for OBL using the original technique.

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