AIM: To investigate the relationship between nocturnal blood-pressure declining(dip)and retinal nerve injury of patients with open angle glaucoma and normal tension glaucoma.

METHODS: The procedure included vision field examination, OCT checking of the average retinal nerve fiber layer thickness, 24-hour monitoring of intraocular pressure, 24-hour ambulatory blood pressure monitoring on 51 ophthalmic clinic's test subjects(51 eyes)with open angle glaucoma and normal-tension glaucoma, then the differences between three DIP groups were compared.

RESULTS:The patients were classified into three groups according to dip, and there were significant variance in the value of mean defect(MD)(P=0.032), intraocular pressure peak value(P=0.003), and visual field defect score deviation(P=0.041)among the three groups. There was significant dip differences(P=0.028)among the visual field defect progressing group, visual field defect invariant group and visual field defect improving group: The visual field defect progressing incidence rate in overdipper group(50%)was higher than that in non-overdipper group(7%). The RNFL correlated factors were the nocturnal minimum mean arterial-pressure and dip(P=0.011, P=0.032,R²=0.081); MD correlated factor was intraocular pressure fluctuations(P=0.026,R²=0.115); pattern standard deviation's correlated factors were intraocular pressure fluctuations and dip(P=0.020, P=0.044, R²=0.141).

CONCLUSION: Normal tension glaucoma demonstrated a higher incidence rate of excessive declining of nocturnal blood pressure than open angle glaucoma. Overdipper group has a higher incidence rate of visual field defect progressing than non-overdipper group. This result supports that there is obvious vision damage progress in the nocturnal blood-pressure excessive declining group. The nocturnal blood pressure value of declining in the visual field defect progressing group is higher than the other two groups. The data confirms that both the excessive declining of nocturnal blood pressure and the excessive fluctuations of diurnal intraocular pressure are high risk influential factors in glaucoma retinal nerve injury progressing.