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Retinal capillary density in patients with arterial hypertension: 2-year follow-up
P Kutschbach1, S Wolf, M Sieveking
1Augenklinik der Medizinischen Fakultät der RWTH Aachen, Germany.
Insights
Essential hypertension worsens retinal microcirculation over time, evidenced by decreasing capillary flow velocity. This progression occurs even when blood pressure is controlled, indicating ongoing vascular damage.
Area of Science:
- Ophthalmology
- Cardiovascular Science
- Medical Imaging
Background:
- Arterial hypertension is a significant risk factor for cerebrovascular and cardiovascular diseases.
- Essential hypertension is associated with reduced perifoveal capillary density and flow velocity.
- Retinal microcirculation changes in hypertension require further investigation for their time course.
Purpose of the Study:
- To prospectively quantify changes in the retinal microcirculation in patients with essential hypertension.
- To evaluate the time course of alterations in the perifoveal capillary network.
Main Methods:
- Video-fluorescein angiography was performed on 33 essential hypertension patients at baseline and after 2 years.
- A scanning laser ophthalmoscope captured digital angiograms for off-line analysis.
- Digital image analysis quantified perifoveal intercapillary areas (PIA) and mean capillary flow velocity.
Main Results:
- Hypertensive patients exhibited increased PIA and decreased capillary flow velocity at baseline compared to controls.
- Capillary flow velocity significantly decreased further during the 2-year follow-up period.
- Perifoveal intercapillary areas (PIA) did not show significant changes over the follow-up.
Conclusions:
- A continuous decline in capillary flow velocity indicates progressive microcirculatory impairment in essential hypertension, even with controlled blood pressure.
- This suggests ongoing vascular damage not fully captured by blood pressure monitoring alone.
- Further research using this technique could assess antihypertensive therapy effectiveness and identify patients at risk for cerebrovascular events.
Background:
Arterial hypertension is known to be an important risk factor for cerebral and cardiovascular disease. Previous studies have demonstrated a decrease of capillary density in the perifoveal network in tandem with decreased capillary flow velocity in patients with essential hypertension. In a prospective study we quantified the retinal microcirculation in order to evaluate the time course of changes in the perifoveal network.
Methods:
Thirty-three patients with essential hypertension (mean age 45 +/- 14 years) underwent video-fluorescein angiographic studies at baseline and at 2 years 28 +/- 6 months) thereafter. The angiograms were obtained with a scanning laser ophthalmoscope and were digitally recorded. By means of digital image analysis we quantified off-line the mean area of perifoveal intercapillary areas (PIA) and the mean capillary flow velocity.
Results:
At baseline, the patients with hypertension showed significantly increased PIA and a significantly decreased capillary flow velocity compared with reference values. During the follow-up period the capillary flow velocity decreased further significantly, whereas the PIA showed no significant change.
Conclusions:
The continuous decrease of capillary flow velocity demonstrates a progression of altered microcirculation in patients with essential hypertension whose blood pressure was believed to be well controlled. Further studies with this technique may be useful to determine the influence of antihypertensive therapy and may help to identify patients at risk for cerebrovascular events.