Abstract
To study the accuracy and reliability of optical pachymetry using the Alcon WaveLight FX500 during laser-assisted in situ her atomileusis (LASIK) I K). Materials and methods: This was a retrospective chart review of 90 eyes from 45 patients who had undergone LASIK (mean age 35.2 8.2 years||19 males, 26 females). The WaveLight ES200 lemtosecond laser was programmed to cut LASIK flaps at a desired depth of 120 pm. Optical low-coherence reflectometry (Wave Light KX500) was used to measure central corneal thickness prior to lifting the flap, and the residual stromal bed immediately after excimer ablation. Flap thickness (FT) was calculated using simple subtraction. Optical coherence tomography (OCT) was used to measure central corneal thickness, flap thickness, and residual stromal bed M the postoperative period and the results compared to intraoperative measurements. Results: Mean programmed FS200 FT Was 119 pm. Mean FT using EX500 optical pachymetry was 109 pm. The difference between FS200-programmed and EX500-measured FT was 9 pm (P<0.001). There was also a significant difference between the EX500 and OCT FT (109 p.m vs 119 pm, respectively||P<(1.001). Conclusion: FT values calculated tsing intraoperative FX500 optical pachymetry were significantly lower than programmed FS200 values or OCT measurements.