COMPARATIVE LOCALIZED CORNEAL BIOMECHANICAL CHANGES FOLLOWING LASER VISION CORRECTION USING MOTION TRACKING BRILLOUIN MICROSCOPY

Published 2023 - 27th ESCRS Winter Meeting

Reference: O1 | Type: Free Paper Submission | DOI: 10.82333/3myk-0820

Authors: Imane Tarib* ¹ , Hongyuan Zhang ¹ , Lara Asroui ¹ , Giuliano Scarcelli ² , J.Bradley Randleman ¹

¹Cole Eye Institute,Cleveland Clinic,Cleveland,United States, ²Fischell Department of Bioengineering,University of Maryland,Maryland,United States

Purpose

To identify focal biomechanical alterations after LASIK, SMILE and PRK using motion tracking Brillouin microscopy.

Setting

Prospective study at the Refractive Surgery department, Cole Eye Institute, Cleveland Clinic, Ohio, USA.

Methods

Fifteen patients, including 5 patients undergoing LASIK surgery (L), 5 patients undergoing SMILE (S) surgery and 5 patients undergoing PRK (P). Patients had motion tracking Brillouin microscopy performed preoperatively and 3 months postoperatively. Changes in localized Brillouin shift were measured at multiple points within the central 8mm of the cornea and regional Brillouin maps were constructed. Pre and Postoperative Mean Brillouin shifts (Mean) and pre-post difference maps were created, Maximum Brillouin shift (Max), Minimum Brillouin shift (Min) were measured in MHz.

Results

Main Outcome Measures: Determining the ability of motion tracking Brillouin microscopy to characterize focal biomechanical alterations in different groups of LVC. Sex (L=80% male, S=20% male, P=40% male) Mean age (L=35.2, S=35.2, P=38.6). Mean Central Corneal Thickness CCT in microns (L=559, S=562, P=523) Mean residual stromal bed in microns (L=376 S=345 P=395). Mean preoperative Brillouin shift in MHz (L=5.694 S=5.702 P=5.686) with no significant difference between all groups (p>0.05). Pre-Postoperative Brillouin shift difference maps found Mean Brillouin Shift in MHz (L=33.04 S=14.04 P=19.90), Maximum Brillouin Shift in MHz (L=40.34 S=22.05 P=28.79), Minimum Brillouin Shift in MHz (L=23.41 S=7.09 P=10.39). Significant differences were found between LASIK and SMILE and between LASIK and PRK (p<0.05), but no significant difference was found between SMILE and PRK (p>0.05)

Conclusion

Motion tracking Brillouin microscopy is sensitive to biomechanical alterations after LVC procedures. Early results indicate a difference between LASIK, SMILE & PRK with LASIK inducing greatest corneal weakening than the other procedures. SMILE & PRK induce similar weakening.