Ocular pulse amplitude in normal tension and primary open angle glaucoma.

PURPOSE: (1) To investigate the relationship of ocular pulse amplitude (OPA) with intraocular pressure (IOP) and corneal thickness. (2) To evaluate OPA in patients with primary open angle and normal tension glaucoma (NTG).

METHODS

Patients with NTG (n=28), primary open angle glaucoma (POAG) (n=19), and age-matched healthy controls (n=22) underwent 2 consecutive Goldmann and dynamic contour tonometry measurements within 1 month. Central corneal thickness was also measured. A regression model was applied to compare OPA between the diagnostic groups.

RESULTS

OPA increased with rising IOP (slope 0.026/0.033 and P=0.002/<0.0001 for Goldmann/Dynamic tonometry), whereas corneal thickness did not influence pulse amplitude measurements (slope-0.0017/-0.0013 and P=0.11/0.21 after correction for Goldmann/Dynamic tonometry). In a multivariate model correcting for IOP and corneal thickness, OPA was reduced in patients with NTG (P=0.014/0.017 corrected for Goldmann/Dynamic tonometry) or POAG (P=0.015/0.014).

CONCLUSIONS

OPA is reduced in normal tension and POAG patients compared with healthy controls. OPA is influenced by IOP, but not by corneal thickness.