Acute alcohol consumption modulates corneal biomechanical properties as revealed by optical coherence elastography

Abstract

Acute alcohol ingestion has been found to impact visual functions, including eye movement, but its effects on corneal biomechanical properties remain unclear. This study aimed to investigate the influence of acute alcohol consumption on corneal biomechanical properties using optical coherence elastography (OCE). An air-coupled ultrasound transducer induced elastic waves in mice corneas in vivo, and a high-resolution phase-sensitive optical coherence tomography (OCT) system tracked the mechanical waves to quantify the elastic wave speed. In vivo measurements were performed on three groups of age- and gender-matched mice: control, placebo (administered saline), and alcohol (administered ethanol) groups. Longitudinal measurements were conducted over a one-hour period to assess acute temporal changes in wave speeds, which are associated with inherent biomechanical properties of the cornea. The results showed a significant decrease in wave speed for the alcohol group after 10 min of ingestion in comparison to pre-ingestion values (p = 0.0096), whereas the temporal wave speed changes for the placebo group were statistically insignificant (p = 0.076). In contrast, the control group showed no significant changes in elastic wave speed and corneal thickness. Furthermore, a significant difference was observed between the wave speeds of the placebo and alcohol groups at each measurement time point between 10 and 50 min (p < 0.05), though both groups exhibited a similar trend in corneal thickness change. The findings of this study have important implications for clinical assessments and research in corneal disorders, highlighting the potential of OCE as a valuable tool for evaluating such changes.

Keywords: Acute alcohol; Biomechanical properties; Cornea; Optical coherence elastography; Wave speed.

Fig. 1.

Schematic of the experimental setup comprising of a phase-sensitive OCT system and air-coupled ultrasound transducer (AT) for mouse cornea excitation. ARF: acoustic radiation force, C: collimator, FC: fiber coupler, FG: function generator, GS: 2D galvo scanner, L: lens, PC: polarization controller, RF: power amplifier, RM: reference mirror, S: spectrometer, and SLD: superluminescent diode.

Fig. 2.

(a) Cross-section of the central cornea. The blue arrow points to the excitation position, while the dashed yellow boxes indicate the regions of interest used for measuring corneal thickness. (b) Snapshots of elastic wave propagation captured at two different time instants: t = 5.04 ms (top) and t = 5.14 ms (bottom) after excitation. (c) A spatio-temporal map indicating the wave propagation in both the left and right directions from the excitation point. The wave speed was determined using the slope of the space–time map, represented by the green line, for both propagation directions. V: elastic wave speed, Δd: lateral distance, and Δt: propagation time for slope-based speed estimation. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3.

(a) Elastic wave speed and (b) central corneal thickness for control, placebo, and alcohol groups compared over a one-hour period (N = 6 eyes per group, 2 eyes per mouse).

Fig. 4.

A univariate regression analysis of the time series measurements comparing mean wave speed and central corneal thickness for (a) control, (b) placebo, and (c) alcohol groups. For the placebo and alcohol groups, only the measurements after a solution of saline and alcohol ingestion, respectively, were included in the graphs. Elastic wave speed had a significant negative correlation with central corneal thickness for placebo and alcohol groups, but the negative correlation in the control group was statistically insignificant.

Fig. 5.

Comparison of the temporal variations in elastic wave speed among the control, placebo, and alcohol groups relative to their respective baselines. The baseline refers to the wave speeds measured before the ingestion of water and ethanol for the placebo and alcohol groups, respectively, while the baseline speed for the control group corresponds to the measurement at the 0–10-minute time interval.