Brillouin Microscopy In Patients With Myopia: A Pilot Study

Brillouin microscopy is a non-invasive imaging technique that assesses tissue mechanical properties by analyzing light–acoustic interactions. It enables in vivo evaluation of corneal elastic and viscoelastic properties and may provide insight into corneal biomechanics in ocular disease. Established biomechanical parameters have been shown to be negatively associated with spherical equivalent and axial length; however, data on Brillouin shift measurements in myopic eyes are lacking. This study evaluates potential biomechanical differences between myopic and emmetropic eyes using the Brillouin Optical Scanner System (BOSS, Intelon Optics) and assesses measurement repeatability.

Vienna Institute for Research in Ocular Surgery (VIROS), a Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria.

This prospective pilot study is designed to include 60 participants, with 20 subjects per group (emmetropic controls, low myopia, and high myopia). Corneal Brillouin modulus (BM) was measured three times per study eye using BOSS, and the mean value was used for analysis. Group differences in mean BM were assessed using one-way ANOVA and ANCOVA adjusted for age. Refractive error (subjective spherical equivalent), axial length, anterior chamber depth, and best-corrected visual acuity (logMAR) were compared across groups. Measurement repeatability was evaluated using the intraclass correlation coefficient (ICC).

A preliminary analysis of 58 eyes showed no significant difference in mean corneal BM between emmetropic, low myopic, and high myopic subjects (ANOVA, p = 0.639). Adjustment for age using ANCOVA confirmed the absence of a group effect (p = 0.656). Spherical equivalent differed significantly between groups (p < .001), as did axial length (23.20 mm, 24.44 mm, and 26.78 mm for emmetropic, low, and high myopic groups, respectively; p < .001). Repeatability analysis demonstrated moderate reliability for single Brillouin measurements (ICC = 0.671, p < .001) and good reliability when averaging three scans (ICC = 0.859, p < .001).

In this preliminary cohort, Brillouin-based corneal biomechanical properties did not differ across refractive groups despite significant refractive and biometric differences. Averaging multiple scans improved measurement reliability. These findings support the feasibility and repeatability of Brillouin microscopy and provide a basis for larger future studies.