## 3 Results  
### Iop Measurements  
Analyzing the cavitation bubble dynamics through the Rayleigh-Plesset relation, or energy and momentum conservation equations, the first bubble collapse time \(\tau_{c}\) can be related to the maximum bubble radius or to the bubble energy by [27,28]:  
\[\tau_{c}=0.915R_{max}\sqrt{\frac{\rho}{p_{0}}} \tag{1}\]  
\[E_{B}=\frac{4}{3}\tau\rho R_{max}^{3}(\frac{0.915}{\tau_{c}})^{2}, \tag{2}\]  
where \(R_{max}\) is the maximum bubble radius, \(p_{0}\) is the liquid pressure, \(\rho\) is the density, and \(E_{B}\) is the bubble energy. In addition, \(\tau_{c}\) can be written as follows:  
\[\tau_{c}=(\frac{3E_{B}}{4\pi})^{1/3}\frac{0.915\sqrt{\rho}}{p_{0}^{5/6}} \tag{3}\]  
which could be rewritten as:  
\[p_{0}=(\frac{0.915}{\tau_{c}})^{6/5}(\frac{3E_{B}}{4\pi})^{2/5}\rho^{3/5}. \tag{4}\]  
These relations show that the first bubble collapse time \(\tau_{c}\) and its maximum bubble radius \(R_{max}\) depend on the applied laser pulse energy [29]; part of this energy is converted into luminescence light, mechanical energy, i.e., shock waves, and about 20% of the laser pulse energy (for 6 ns pulses) is converted into bubble energy [28]. Therefore, based on Equation (4) and under constant bubble  
Figure 7: Typical STM signal generated in the AC of an ex vivo pig eye. (**a**) Growth and first collapse of the cavitation bubble \(\tau_{c}\), (**b**) region (3) corresponds to the contribution of multiple microbubbles after the first collapse, and (**c**) shows a zoom into (**b**)’s inset, which corresponds to the segment of the STM that contains the collapse time value of interest for three close per-pulse energy levels. The signals were triggered to match at the bubble collapse. energy and media properties, it is possible to infer the liquid pressure by measuring the first bubble collapse time. We used Equation (3) to analyze and understand the results from the cavitation effect in the AC, because it shows how the first collapse time of the cavitation bubble depends on the fluid pressure and the laser pulse energy. Figure 8 shows the influence of the applied pressure (within the IOP range) on the collapse time for two values of pump energy. These results are in good agreement with the work published by [PERSON] et al. and [PERSON] [21; 26], where they obtained the same STM trends for a larger pressure range (0-100 or 0-250 mmHg) and pressure resolution (10 or 50 mmHg). It must be noted that they used a quartz pressure chamber (2 mL) and a tonometric artificial eye model, respectively. Figure 8 shows that the collapse time follows a linear trend within the IOP range and that it is independent of the pig eye size (S and M). In the range between 10 and 30 mmHg, we can observe a slight dispersion of the collapse time, most likely due to the accommodation effects (AE) in the AC, as reported by [PERSON] et al. [30]. The accommodation effect occurs while pressurizing an ex vivo pig eye through the optic nerve, causing a decrease in the depth of the AC; if the external applied pressure begins on 10 mmHg and it increases up to 30 mmHg, the AC depth decreases \(\approx\)100 \(\upmu\)m. In the experimental setup, the cavitation bubbles are generated \(\approx\)200 \(\upmu\)m below the corneal endothelium. Figure 9 is similar to Figure 8, but uses single STM signals per data point, i.e., does not use averages. With three shots-per-pressure values, we can observe a minimal dispersion of the data for medium-sized pig eyes (circles and diamonds), and a linear trend is preserved; however, for the small pig eye (squares), the dispersion increases and the linear trend is not is clear; this is probably due to the AE within the AC (10 to 30 mmHg). For small eyes, it is clear that the cavitation bubble would be closer to the boundaries, such as the iris and cornea; it could be expected, then, that the bubble growth follows a different trend. Figure 8: Collapse time vs. external pressure induced into the AC for two ex vivo pig eyes.