## 3 Results  
Figure 3 depicts the ppTMD measured in response to pairs of increasing mean pressures and pulse amplitudes in human and nonhuman primate eyes. Mean baseline pressures were experimentally controlled at 16, 24, 32, and 40 mmHg. Pulse amplitudes were set to 2.5, 5, 7.5, and 10 mmHg for each mean pressure. The pulse frequency was maintained at 30 pulses/min. In both human and monkey eyes, when mean pressure remained constant, the ppTMD increased along with the experimentally controlled increase in pulse amplitude. The ppTMD is at its highest value at the lowest mean pressure of 16 mmHg at each pulse amplitude. A systematic increase in mean baseline pressure reduces the ppTMD response at each pulse amplitude. The ppTMD values for the 4 mean pressures at lower pulse amplitudes are similar. As the mean pressure increases, the relative effect of the pulse amplitude on ppTMD decreases. The increased separation of the curves is consistent with movement along the length-tension curve as pressure rises. As the baseline stress from pressure rises, the TM experiences greater baseline strain. Increased baseline strain deformation results in progressively reduced TM deformation in response to the same pulse transient. Figure 2: Representative TM velocity (**A**) and corresponding displacement trace (**B**) resulting from 10 mmHg pressure-induced pulse transients above a baseline of 16 mmHg IOP in the human eye. The peak-to-peak TM displacement ((**B**), dashed arrow) and recoil response ((**B**), small solid arrow) were used for quantitative analysis of the data. The red line in graph (**C**) represents the normalized pressure recorded by the pressure transducer overlaid on the corresponding normalized displacement recorded by OCT (black line). Figure 4 shows how pulse frequency affects the ppTMD response to stepwise increases in mean pressure and pulse transient parameters in a nonhuman primate eye. The ppTMD curves showed quite limited differences in response to changes in frequency. At a fixed mean pressure, the ppTMD increased with the rise in pulse amplitude. When mean pressure was 16 or 24 mmHg, the ppTMD of the higher frequencies decreased slightly compared with the 30 pulse/min, made more evident with higher pulse amplitudes (7.5 mmHg and 10 mmHg). With higher mean pressure (32 mmHg or 40 mmHg), when pulse amplitude was 2.5 mmHg and 5 mmHg, the ppTMD responses to pulse frequency were similar. When pulse amplitude was 7.5 mmHg and 10 mmHg, the ppTMD was at its highest value for the lowest frequency of 30 pulse/min. Figure 5 shows the normalized TM recoil time constant for various mean pressures and pulse amplitudes in human and monkey eyes. Using a fixed pulse amplitude while increasing mean pressure, the statistical analysis revealed significant time constant differences. The mean pressure increase resulted in a decrease in the time constant while maintaining the same pulse amplitude. The \(p\) values for the TM recoil time constant over different mean pressures and pulse amplitudes are listed in Table 1. A Multiple Comparison test indicated that in all cases, the TM showed significantly faster recoil (i.e., shorter time constant) at 40 mmHg IOP compared with 16 mmHg IOP (\(p<0.05\)).