Intraocular pressure profile during the modified diurnal tension curve using Goldman applanation tonometry and dynamic contour tonometry

The aim of this study was to compare the intraocular pressure (IOP) profile during the modified diurnal tension curve (mDTC) using Goldman applanation tonometry (GAT) and dynamic contour tonometry (DCT) in treated glaucomatous eyes. Eligible subjects were submitted to the mDTC using GAT and DCT in this sequence. IOP measurements were performed at 8 a.m., 10 a.m., 2 p.m., and 4 p.m.. Central corneal thickness was measured using ultrasound pachymetry in the morning. Statistical analysis was performed using paired Student's t test and Bland-Altman plot. The mean difference between DCT and GAT measurements was 0.9 mmHg. The mean +/- SD IOP measurements during the mDTC were 19.68 +/- 4.68, 17.63 +/- 4.44, 17.25 +/- 5.41, and 17.32 +/- 4.25 mmHg using GAT and 19.97 +/- 4.75, 18.79 +/- 4.61, 19.53 +/- 5.30, and 19.43 +/- 5.45 mmHg using DCT. IOP measurements were higher in the morning (8 a.m.) and decreased throughout the day using both tonometers. The difference between IOP measurements using GAT and DCT was smaller in the morning and increased throughout the day. The IOP variability using GAT was higher than using DCT. Corneal biomechanical properties might help explain our findings.