Study of Relationship between Blood Pressure and Visual Acuity among Nigerians.

Abstract

The study was aimed to determine prevalence of different types of visual acuity (VA) and blood pressure (BP) among Hausa ethnic population of northwestern Nigeria. The association of sex with VA and BP were investigated. The relationship between VA and BP was also evaluated. A total of 195 subjects (120 males and 75 females) with mean age of 20.14 ± 1.86 (18‐25 years) participated. BP and VA were determined using standard protocols. Fisher's exact (Fe) test was used to investigate the relationship using SPSS version 20. <em style=“mso‐bidi‐font‐style: normal;”>P < 0.05 was set as level of significance and +/‐ 1.96 as a critical value for the post hoc. The result shows that normal (6, 6) visual acuity had higher prevalence in both right (81%) and left (81.5%) and other forms were the least (19% right and 18.5% left). For BP 42.1% and 43.1%, 45.1% and 39.5%, 11.3% and 0%, 1.5% and 17.4% were optimal, normal, high normal and hypertensive for both systolic and diastolic respectively. Gender was found to be associated with systolic BP (Fe value= 34.47, P< 0.001), diastolic BP (Fe value= 16.54, P< 0.001), right VA (Fe value= 15.21, P< 0.001) and left VA (Fe value= 13.10, P= 0.001). A statistically significant relationship was observed between systolic BP and right VA (Fe value = 33.91, P< 0.001) Variables Systolic blood pressure Total Optimal Normal High normal hypertensive Right visual acuity Sub normal I (5,6) Count 26 3 1 0 30 Expected Count 12.6 13.5 3.4 0.5 30.0 Residual 13.4 ‐10.5 ‐2.4 ‐0.5 Std. Residual 3.8 ‐2.9 ‐1.3 ‐0.7 Normal (6,6) Count 53 83 20 2 158 Expected Count 66.4 71.3 17.8 2.4 158.0 Residual ‐13.4 11.7 2.2 ‐0.4 Std. Residual ‐1.6 1.4 0.5 ‐0.3 Sub normal II (others) Count 3 2 1 1 7 Expected Count 2.9 3.2 0.8 0.1 7.0 Residual 0.1 ‐1.2 0.2 0.9 Std. Residual 0.0 ‐0.7 0.2 2.7 Fisher's Exact Value = 33.91, P< 0.001 and left VA (Fe value = 32.44, P< 0.001). Similar relationship was noticed with diastolic BP Variables Diastolic blood pressure Optimal Normal Hypertensive Right visual acuity Sub normal I (5,6) Count 26 3 1 Expected Count 12.9 11.8 5.2 Residual 13.1 ‐8.8 ‐4.2 Std. Residual 3.6 ‐2.6 ‐1.8 Normal (6,6) Count 57 70 31 Expected Count 68.1 62.4 27.5 Residual ‐11.1 7.6 3.5 Std. Residual ‐1.3 1.0 0.7 Sub normal II (others) Count 1 4 2 Expected Count 3.0 2.8 1.2 Residual ‐2.0 1.2 0.8 Std. Residual ‐1.2 0.7 0.7 Fisher's Exact Value = 28.71, P=< 0.001 In conclusion, gender had an association with VA and BP. Moreover, VA could be influenced by BP