Distribution Of Intraocular Pressure And Related Risk Factors In A Highly Myopic Chinese Population: An Observational, Cross-Sectional Study

Background: The aim of this work is to investigate the distribution of intraocular pressure and the correlated risk factors in a highly myopic Chinese population. Methods: A total of 884 Chinese participants with bilateral high myopia (<= -6.00 D spherical power) were included from the Zhongshan Ophthalmic Center-Brien Holden Vision Institute High Myopia Cohort Study. All participants underwent a comprehensive ocular examination, including ocular biometry, cycloplegic refractometry, and intraocular pressure measurement with Goldmann applanation tonometry. Information on smoking and drinking status was also collected. Results: The mean spherical equivalence of left eyes was -10.02 +/- 3.58 D with a mean axial length of 27.48 +/- 1.55 mm. The overall mean intraocular pressure was 15.1 +/- 2.4 mmHg (95% confidence interval, 15.0 to 15.3 mmHg). The intraocular pressure in the -6.00D to -7.99D spherical equivalence group, -8.00D to -9.99D spherical equivalence group, and <= -10.00 D group were 15.3 +/- 2.4 mmHg, 15.1 +/- 2.5 mmHg, and 15.0 +/- 2.4 mmHg, respectively (p = 0.979). In multiple regression models, intraocular pressure in high myopes was not associated with spherical equivalence (p = 0.354) or axial length (p = 0.601), but significantly higher in those who were younger (non-standardised beta, -0.018; p = 0.007), smoked tobacco (non-standardised beta, 1.085; p = 0.001) and had greater central corneal thickness (non-standardised beta, 0.021; p < 0.001). Conclusion: Intraocular pressure was 15.1 +/- 2.4 mmHg among subjects with a mean age of 22.8 years in this highly myopia Chinese population. These findings suggested that highly myopic Chinese persons of a younger age and greater central corneal thickness were more likely to have higher intraocular pressure.