Effect of corneal thickness on intraocular pressure measurements with the Pascal dynamic contour, Canon TX‐10 non‐contact and Goldmann applanation tonometers in healthy subjects

Abstract

Purpose:To investigate the effects of central corneal thickness (CCT) on intraocular pressure (IOP) measurements of the Pascal dynamic contour tonometry (DCT), Canon TX-10 non-contact tonometry (NCT) and Goldmann applanation tonometry measurements (GAT) in healthy subjects. Methods: IOP values of 135 eyes with normal corneas of 135 healthy volunteers were determined by DCT, NCT and by GAT. The CCT was measured using an ultrasonic pachymeter after all IOP determinations had been made. Results: When DCT measurements were compared (IOP = 17.52 Ϯ 2.0 mmHg) with NCT measurements (IOP = 16.54 Ϯ 2.77 mmHg) and GAT measurements (IOP = 15.07 Ϯ 2.35 mmHg), DCT measurements were significantly higher than NCT and GAT (p < 0.001). There was a significant correlation between CCT with both NCT (r = 0.260, p = 0.003) and GAT measurements (r = 0.257, p = 0.005). There was a weak correlation that was not statistically significant between CCT and DCT (r = 0.160, p = 0.079). Conclusion:The IOP measurements with DCT seem to be less dependent on CCT. NCT appears to be more affected by variation in CCT than GAT.

Reproducibility of ocular response analyzer measurements and their correlation with central corneal thickness

“…A previous study comparing GAT, DCT and noncontact tonometry (NCT) measurements in healthy subjects confirmed significant correlation between CCT and both NCT and GAT. No significant correlation between CCT and DCT measurements was found [13]. Another study found DCT measurements to be affected by corneal curvature [10,11].…”

Goldmann applanation tonometry versus non-contact tonometry: a comparative study

“…Many previous studies have also included eyes on anti-glaucoma medications. 1,3,8,10,13 The effect of treatment on the hydration properties of the cornea was overlooked as this was not the aim of the present study.…”

“…1,3,9,13 The shortcomings of present study were dependency bias since both eyes of a subject was included. Also, certain biases like observer bias may creep in, though measures were taken to avoid same by taking average of multiple readings and masking.…”

Intraocular pressure in keratoconus

“…2002; Tonnu et al. 2005; Pelit et al. 2009) and subjects with glaucoma and ocular hypertension (Erdurmus et al.…”

“…Previous studies of both normal (Tonnu et al. 2005; Pelit et al. 2009) and keratoconus (Edmonds 1993; Papastergiou et al.…”