Age-dependence of in vivo Brillouin-spectroscopy measurements in normal cornea

Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Monday 09/10/2017 | 08:00-10:30

Paper Time: 10:16

Venue: Room 2.1

First Author: : P.Shao USA

Co Author(s): :    A. Eltony   T. Seiler   T. Seiler   S. Yun           

Abstract Details

Purpose:

Brillouin spectroscopy can non-invasively measure biomechanical constants of soft tissue like the cornea, and it has been introduced to ophthalmology applications. However, how aging is influencing Brillouin measurements is unclear. In this paper, we present the age dependence of the longitudinal modulus of the central cornea in vivo using Brillouin scattering data in healthy subjects.

Setting:

Institute of Refractive Surgery (IROC), Zürich, Switzerland and Wellman Center for Photomedicine, Harvard Medical School, Boston, USA

Methods:

Brillouin-shift measurements were performed using a Brillouin-microscope (Brillouin optical scanning system, BOSS, Intelon Optics, Boston). 5 axial scans in the central region of the corneas (< ~ 1 mm form the pupil center) were carried out on each volunteer. Average Brillouin frequency shift of the anterior stroma was quantified. Statistical comparison was performed. 100 volunteers were recruited for the study, with an average age 40.02 ± 14.04 yld (15 – above 55, 45% female). General inclusion criteria is healthy cornea with no history of surgical procedures, and no high myopia/hyperopia.

Results:

The reproducibility of the measurement (3 different days, same eye and same operator) was ±7.2 MHz (SD). The mean Brillouin shift across all ages is 5.725 ± 0.016 GHz (SD). A trend towards increasing Brillouin shift with age was observed, despite significant inter subject variation, with a rate of increase of about ~ 4 MHz/decade (p < 0.001, Pearson’ r = 0.3). No significant difference was observed between left and right eyes.

Conclusions:

Despite with the person-to-person variation, we observed a pattern of increasing Brillouin shift with age, which suggests increasing corneal stiffness. This trend is consistent with prior studies showing a stiffening effect with age in ex vivo human corneas via direct stress-strain measurement and provides base line for measurements on corneas with pathological conditions.

Financial Disclosure:

NONE