Effect of Chatter Lines and Opaque Bubble Layer on Enhancement Rate for Optimized Femto-LASIK
Narrative Responses:
Purpose
To determine the relationship between chatter lines and opaque bubble layer (OBL) and enhancement rate for FS200 LASIK flaps.
Methods
We reviewed medical records of patients who underwent LASIK on the FS200/Allegreto Wavelight platform at the Cole Eye Institute, Cleveland, OH from March 2011 through August 2012. We analyzed all eyes corrected for distance and monovision. Patients were divided into four groups based on spherical equivalent: high myopia (>-6D, n=149), moderate myopia (>-3D to 6D, n=263), mild myopia (0D to -3D, n=192) and hyperopia (n=69). Patients were excluded for follow up less than 3 months.
Results
We reviewed a total of 673 eyes, of which, we excluded 109. We found no significant difference between enhanced and non-enhanced eyes regarding incidence of chatter, incidence of OBL, preoperative keratometry and corneal astigmatism among all groups. Enhanced highly myopic patients had statistically significantly thicker corneas compared to non-enhanced. Otherwise, no other groups showed a difference in preoperative pachymetry. Among all myopic groups, those who received enhancements were significantly older, while only the moderate myopic group showed a significantly higher proportion of monovision treatments among the enhanced group compared to the non-enhancement group.
Conclusion
Chatter lines and OBL generated by the FS200 do not appear to significantly increase the enhancement rate. Additionally, keratometry and corneal astigmatism do not correlate with enhancement rate. Older age may correlate with increased rate of enhancement. Also, thicker corneas may increase the need for enhancement in high myopic treatments.