Low night diastolic ocular perfusion pressure ups risk of normal tension glaucoma progression
Low nocturnal diastolic ocular perfusion pressure (DOPP) is an independent predictor of normal tension glaucoma (NTG) progression, a recent study has found.
Researchers followed for 5 years 65 NTG patients (mean age at follow-up 68.2±9.8 years; 50.8 percent female) with baseline 24-hour intraocular pressure and blood pressure (BP) measurements. The modified Anderson criteria was used to assess disease progression, while Cox proportional hazards models were used to determine the relevant risk factors.
Over a mean follow-up time of 6.0±0.7 years, the disease progressed in 35.4 percent of the eyes (n=23) and the mean rate of global visual field (VF) change was –0.70±1.16 dB per year.
In terms of systemic BP parameters, mean daytime (75.90±10.16 vs 80.35±8.94 mm Hg; p=0.038), evening (75.54±6.90 vs 80.37±8.75; p=0.0080) and night (70.30±9.58 vs 75.82±6.82; p=0.009) diastolic BPs were significantly lower in those whose disease progressed. No between-group differences were observed in terms of systolic BP and mean arterial pressure.
Multivariable analysis revealed that low nocturnal DOPP at baseline was associated with a significantly elevated risk of glaucomatous VF progression at follow-up, such that each unit drop in night time DOPP increased the risk of progression by 1.4 times (hazard ratio [HR], 0.71; 95 percent CI, 0.55–0.93; p=0.012).
Baseline pattern standard deviation was likewise a significant predictor of progression, wherein each unit increase in baseline values was associated with a 14-percent increase in the risk of disease progression (HR, 1.14; 1.00–1.29; p=0.05).