Bubble release sign in keratorefractive lenticule extraction

The purpose of this study was to describe the bubble release sign that allows correct anterior and posterior lenticular plane delineation in lenticule-based refractive surgery. This sign describes the escape of the air bubble formed as a part of the opaque bubble layer on entry into the anterior plane of the lenticule. This allows ideal dissection of the lenticule from the overlying cap and underlying stroma, thereby reducing the complications arising from incorrect lenticular dissection and extraction. The escape of the bubble also acts as a confirmation that the surgeon has entered the anterior plane, and not the posterior, as the bubble forms only in the anterior plane as a result of accumulation of micro air bubbles.