[Spectral domain optical coherence tomography to assess the association between the inner caliber of large retinal vessel and the primary hypertension].

ABSTRACT

OBJECTIVE: To assess the inner caliber of large retinal vessel quantitatively using spectral domain optical coherence tomography (SD-OCT) and to reveal the association between changes in the inner caliber of large retinal vessel and the primary hypertension. METHODS: A retrospective case-control study was carried out including 215 cases (with primary hypertension) and 210 controls (without primary hypertension) admitted to our hospital since 2009 and all the cases and controls were grouped according to age. SD-OCT was performed to assess the inner caliber of large retinal vessel quantitatively including retinal artery inner caliber (RAIC), retinal vein inner caliber (RVIC) and retinal arterio-venous inner caliber ratio (RAVICR). The differences in the inner caliber of large retinal vessel between the cases and the controls in each age groups were analyzed by t test. In all cases, multiple comparisons were performed according to their blood pressure level by SNK test of one way ANOVA. The RAVICR was also correlated with the following relevant determinants via multiple stepwise regression analysis: age, diastolic and systolic blood pressure. RESULTS: In each age group of cases (< 40, 40 to 49, 50 to 59, 60 to 69, ≥ 70 years), the values of RAIC were (93.0 ± 6.3), (86.2 ± 6.1), (84.5 ± 5.1), (84.0 ± 5.5), and (81.7 ± 5.4) µm respectively, and the values of RVIC were (129.4 ± 5.8), (130.7 ± 6.5), (129.6 ± 5.4), (132.2 ± 6.4), and (131.6 ± 5.1) µm respectively, and the values of RAVICR were (0.720 ± 0.07), (0.661 ± 0.06), (0.653 ± 0.04), (0.637 ± 0.06), and (0.621 ± 0.05) µm respectively. Compared with controls, RAIC (t = -4.813, -10.893, -15.689, -8.811, and -10.151 respectively; P < 0.05) and RAVICR (t = -3.276, -8.654, -13.470, -7.801, and -9.210 respectively; P < 0.05) were significantly decreased in each age group of cases. Multiple comparisons were made among each systolic and diastolic pressure groups in all cases. In systolic groups, difference of RAIC or RAVICR were significant (SNK test)between 140 to 149 mm Hg (1 mm Hg = 0.133 kPa) and 170 to 179 mm Hg group (q = 9.46, 10.61; P < 0.05), 140 to 149 mm Hg and ≥ 180 mm Hg group (q = 11.03, 13.98; P < 0.05), 150 to 159 mm Hg and 170 to 179 mm Hg group (q = 8.13, 8.82; P < 0.05), 150 to 159 mm Hg group and ≥ 180 mm Hg group (q = 9.01, 9.97; P < 0.05). In diastolic groups, difference of RAIC or RAVICR were significant (SNK test) between 90 to 99 mm Hg and 100 to 109 mm Hg group (q = 6.79, 5.95;P < 0.05), 90 to 99 mm Hg and ≥ 110 mm Hg group (q = 9.72, 10.21; P < 0.05), 100 to 109 mm Hg and ≥ 110 mm Hg group (q = 5.93, 6.07; P < 0.05). RAVICR was associated with the diastolic and systolic blood pressure revealed by the multiple stepwise regression analysis (ANOVA F = 11.231; Standardized regression coefficient ß = -0.024, -0.019, respectively; P < 0.05). CONCLUSIONS: Quantitative assessment for the inner caliber of large retinal vessel can be done by SD-OCT. The value of RAI and RAVICR were correlated with diastolic and systolic blood pressure in primary hypertension.