Prevalence of hypertensive retinopathy in patients with pregnancy-induced hypertension (PIH) at Parirenyatwa Group of Hospitals.

Abstract

Pregnancy-induced hypertension(PIH)is a spectrum of disorders associated with significant fetal and maternal morbidity and mortality. It is a multisystem disorder which does not spare the visual system. Some effects of PIH on the retina(hypertensive retinopathy)and choroid(hypertensive choroidopathy),can be potentially blinding if not recognised and managed promptly though in the majority of patients there is resolution within six weeks post-partum without sequelae. As the eye is the “window to one’s body”, the presence of hypertensive retinopathy can predict fetal outcomes, severity and likelihood of progression of pregnancy-induced hypertension.

Objectives: This study sought to: Determine the prevalence of hypertensive retinopathy in patients with PIH presenting at Parirenyatwa Group of Hospitals. Establish the severity of hypertensive retinopathy in the study population. Identify associations between hypertensive retinopathy with age, parity, previous history of PIH, blood pressure (systolic and diastolic), degree of proteinuria and the presence of the Human Immunodeficiency virus (HIV)in the study population. Identify sight-threatening complications associated with hypertensive retinopathy in the study population.

Study design: This was a hospital based cross-sectional study and was carried out fromthe8thofSeptember 2016to the 31stof March2017.Methods: Participants were selected by convenience sampling from patients admitted at Mbuya Nehanda Maternity Hospital. Eligible patients were pregnant women from 24 weeks gestation onwards with a diagnosis of PIH. Patients unwilling to participate in the study, those with pre-existing hypertension, media opacities and systemic illnesses which caused retinal pathology similar to hypertension were excluded from the study. Data was collected using a specially designed study tool .All subjects had a medical history taken and an ocular examination which included visual acuity, anterior segment examination and a dilated fundus examination with both the direct and indirect ophthalmoscope. Fundus photographs were taken for selected cases. The Keith-Wagener-Barker classification of hypertensive retinopathy was used for grading of retinopathy. An overall grade of the hypertensive retinopathy was assigned to each patient on the basis of the eye with the most severe changes.

Results: A total of163 patients were recruited. Seventy-five patients (46%) had gestational hypertension, 74 (45.4%) had pre-eclampsia and 14 (8.6%) had eclampsia. A total of 111 subjects (68.1%) had clinically evident hypertensive retinopathy. Fifty-eight participants(52.3%) had grade 1 changes, 32(28.8%)had grade 2changes, 17(15.3%)had grade 3 and 4(3.6%)had grade 4 hypertensive retinopathy respectively. There was a statistically significant positive association(p<0.05),between hypertensive retinopathy and blood pressure(both systolic and diastolic), proteinuria, severity of PIH, duration of PIH since diagnosis and parity. There was no significant association(p>0.05),between hypertensive retinopathy and HIV status, visual acuity, gestation and maternal age. None of the patients had retinal detachment or choroidopathy.

Conclusion: The prevalence of hypertensive retinopathy was significantly high in our study population in comparison to other studies. Positive risk factors for developing hypertensive retinopathy in our study population included high blood pressure, severity of PIH, proteinuria, duration with PIH and increasing parity. However, the majority of patients did not have sight threatening complications.