Background Physiological decrease in systemic blood pressure during sleep and the effect of antihypertensive drugs may lead to reduction in ocular perfusion and development of optic neuropathy. The aim of this study was to assess blood flow in the vessels of the eyeball and changes in the optic nerve among patients with hypertension and primary open-angle glaucoma.
Material and methods The study was conducted on a group of 69 patients with glaucoma and treated, controlled hypertension. All patients in the survey have been examined both, subjectively and objectively. Additionally 24-h blood pressure records were taken. During ophthalmologic examination the thickness of the nerve fibers and the visual field defects were assessed. Many times during the day intraocular pressure was studied. The ultrasound-Doppler estimated peak systolic velocity, end-diastolic velocity and vascular resistance index in ophthalmic, central retinal and short posterior ciliary arteries. Because of the value of nocturnal blood pressure fall (NBPF) the patients were divided in two groups: non-dippers (NBPF ≥ 10%) and dippers (NBPF > 10%).
Results In the group of dippers perfusion pressure was significantly lower and reduced thickness of the nerve fibers and a greater decrease in the visual field was observed. Statistically significant relationship between peak systolic, end-diastolic flow in ophthalmic and central retinal artery and night perfusion pressure, thickness of nerve fibers, loss in visual field was observed.
Conclusion The night blood pressure fall > 10% is connected with more advanced loss in the visual field and greater degeneration of optic nerve fibers which may result from decrease perfusion in ophthalmic and central retinal artery. The risk factors for progression of glaucoma include low night-pressure perfusion, minimal diastolic blood pressure below 45 mm Hg and reduce ocular blood flow. The above presented correlations are shown to avoid excessive drops of blood pressure in patients with glaucoma and arterial hypertension and indicate the necessity of further research on determining the target value of blood pressure in these patients. The results indicate the necessity for this group of patients to perform the ambulatory blood pressure monitoring study and quantify the pressure drop in the night.
Arterial Hypertension 2010, vol. 14, no 2, pages 128-141.