Ocular pulse amplitude in normal tension and primary open angle glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Ocular Biomechanics

Background:

• Glaucoma diagnosis and monitoring rely on intraocular pressure (IOP) and structural assessments.
• Ocular pulse amplitude (OPA) reflects pulsatile changes in IOP, potentially offering novel diagnostic insights.
• Understanding factors influencing OPA is crucial for its clinical application in glaucoma.

Purpose of the Study:

• To determine the relationship between ocular pulse amplitude (OPA) and intraocular pressure (IOP) along with corneal thickness.
• To assess OPA levels in patients diagnosed with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG).

Main Methods:

• A comparative study involving patients with NTG (n=28), POAG (n=19), and healthy controls (n=22).
• Goldmann and dynamic contour tonometry were used for IOP and OPA measurements; central corneal thickness was also recorded.
• Regression analysis was employed to analyze OPA variations across diagnostic groups, adjusting for IOP and corneal thickness.

Main Results:

• OPA demonstrated a positive correlation with increasing IOP (P<0.001) but was not significantly affected by corneal thickness (P>0.11).
• Multivariate analysis revealed significantly reduced OPA in both NTG (P=0.014) and POAG (P=0.015) patients compared to controls, after adjusting for IOP and corneal thickness.

Conclusions:

• Ocular pulse amplitude (OPA) is significantly diminished in patients with normal tension glaucoma and primary open angle glaucoma.
• OPA is a pressure-dependent parameter, but corneal thickness does not appear to be a confounding factor in its measurement.
• Reduced OPA may serve as a potential biomarker for glaucoma, warranting further investigation.