Detecting the real glaucomas

Correlating IOP with glaucomatous damage: Conclusion of a study
from M. Sullivan Mee 20073

“These findings suggest that DCT-IOP is correlated with glaucomatous damage, and moreover, DCT-IOP is more closely related to extent of glaucoma damage than is Goldmann IOP (GAT-IOP).

The most likely explanation for these results is that GAT-IOP systematically under­estimates IOP compared with DCT-IOP. Our findings also support the hypothesis that corneal biomechanical factors other than CCT are major confounders of applanation tonometry measurements.”


3 M. Sullivan Mee et al. Clinical comparison of PASCAL DCT
and GAT in asymmetric open-angle glaucoma;
(J Glaucoma 2007 Dec;16(8):694–9)

Frequency Distribution of GAT-IOP and DCT-IOP8

2157 eyes of primarliy Mexican ancestry showed a mean ΔIOP
between DCT and GAT of 1.7 mmHg. DCT is calibrated to true IOP
while GAT was calibrated to cadaver eyes in the 1950s.


8 A. Francis et al. Effects of CCT, Curvature, and IOP Level on GAT and DCT; (10.1016/j.ophtha.2006.06.047)