The Influence of Corneal Thickness on Level of Intraocular Pressure in the Group of Healthy Persons and Patients with Primary Open Angle Glaucoma (POAG)

Overview

Aim:
To asses the relation between the level of intraocular pressure (IOP) and central corneal thickness (CCT), and to examine the dependence of CCT on age, sex and refraction in the control group of healthy persons (CG) and the group of patients with POAG.

Methods:
The control group was formed by 42 eyes of healthy people and 20 eyes of patients with POAG. There were 26 women and 16 men in CG with a median age of 27.5 years and a median refraction of 0 D. The study group with POAG included 9 women and 11 men, with a median age of 71 years and median refraction of 0 D. The corneal thickness was measured with an ultrasonic pachymeter and the IOP with an applanation tonometer.

Results:
A mean IOP level in CG was 15,4 ± 5,6 mm Hg and a mean CCT level 558 ± 42 μm. In the study group of POAG there was a mean IOP level 19,6 ± 4,6 mm Hg, and a mean CCT level 562.7 ± 35.7 μm. In the CG a significant positive correlation was found between CCT and IOP (p = 0.01). The dependence of CCT on sex (p = 0.92), refraction (p = 0.99) and age (p = 0.41) was not statistically significant. On the contrary, in the study group of POAG no significant correlation between CCT level and IOP level was found (p = 0.15). The dependence of CCT level on sex (p = 0.43), refraction (p = -0.08) and age (p = -⁠ 0.17) was also not statistically significant. The difference in the CCT level between CG and the study group of POAG was not significant (p = 0.81). The IOP level appeared to be the only significant difference between both groups (p = 0.007).

Conclusion:
The level of IOP was influenced by CCT only in the control group of healthy persons. This dependence was not significant in the group of persons with POAG.

Key words:
central corneal thickness, pachymetry, intraocular pressure, applanation tonometer, primary open angle glaucoma