Peripheral and central pressure waveform parameters are associated with normal tension and primary open-angle glaucoma

Aims: To investigate the association of peripheral and central pulsatile blood pressure with normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG). Methods: Radial pressure pulse waveforms were recorded in 110 glaucoma patients and central blood pressure calculated using a validated transfer function. Glaucoma was defined as definite neuroretinal rim loss assessed by stereo disc assessment, with corresponding confirmed field defect. Diagnosed and current intraocular pressure were recorded as was disease progression within the last 3 years. Comparison was drawn between NTG and POAG, and age/sex matched controls. Results: Self-reported white coat hypertensives were excluded, leaving 70 POAG and 33 NTG patients, age 67±12 yrs, BMI 22±5 kg.m-2, 55 male. Peripheral and central pulse pressures were lower in glaucoma patients than controls (p<0.01 and p<0.0001 respectively). Ocular diastolic and pulse perfusion pressures were lower in subjects with glaucoma (p<0.01). POAG patients had a lower peripheral form factor ((mean-diastolic)/pulse pres- sure) than NTG patients (0.34 and 0.36, p<0.01). The subendocardial viability ratio (SEVR) was lower in NTG than in POAG (1.71 and 1.56, p<0.05) and was negatively associated with glaucoma progression (1.58 in progression, 1.72 stable glaucoma, p<0.05) suggesting a role of diastolic blood perfusion in the eye, an organ that itself has a positive internal pressure. Conclusions: These results indicate that pressure pulsatility and ocular perfusion, especially during diastole, are contributing factors in glaucoma and the progression of the disease.