Measurement device and derivation formula for static ocular compliance

To introduce a device for measuring static ocular compliance (SOC) and propose a best-fit formula. An observational experimental study involving patients with age-related cataracts was conducted between May 2024 and September 2024. Pearson's correlation analysis was used to screen for potential variables that were significantly associated with the SOC. Then, the SOC at six different height differences (recorded as "Δh") was compared, and the best-fit equations for SOC were screened by linear regression analysis. C_Δh was defined as SOC at height difference of Δh mm. A total of 47 eyes of 47 patients (22 males [46.8%] and 25 females [53.2%]) were enrolled. The mean SOC was (0.846 ± 0.274) µL/cmH₂O, with a 95% confidence interval of (0.813-0.879) µL/cmH₂O, with ocular axial length (AL) of (23.74 ± 1.83) mm and central corneal thickness of (541.13 ± 35.34) µm. Furthermore, Pearson's correlation analysis revealed a significant correlation between SOC and AL (all P < 0.001). Using our device, the best-fit formula can be expressed as SOC = 0.948 x C₆₀₀ + 0.067 x AL (R² = 0.985; P = 0.000), with an optimal height difference of 600 mm. The designed in vivo measurement device can accurately measure SOC and derive a best-fit formula.