High blood pressure remains a major health issue worldwide, with profound-and often silent-multisystem effects.

Systemic hypertension (HTN) is a common health problem—affecting more than 800 million people worldwide—that often remains asymptomatic until late in the disease course. It is a major risk factor for both coronary artery disease and cerebrovascular accident.

Although HTN has both genetic and environmental factors, the exact mechanism in the majority of affected individuals is largely unknown. Cardiac hypertrophy, heart failure, aortic dissection and renal failure are all systemic sequelae of the disease process. As we know, hypertensive ocular changes can be the initial finding in a patient with undiagnosed HTN and may have sight-threatening consequences.

Types of Hypertension

Blood pressure (BP) varies throughout the population, based on age, gender, body mass index and diet.

Essential hypertension. About 95% of HTN occurs as this form. Essential HTN does not cause short-term problems and is often called benign hypertension.

Secondary hypertension. A small amount of HTN patients (5%) have this form. It’s caused by underlying conditions, such as renal or adrenal disease.

Malignant hypertension. Some patients have a rapid rise in BP that, if untreated, may lead to death within a year or two. Malignant HTN is characterized by severely elevated BP (systolic greater than 200mg Hg, diastolic greater than 120mm Hg), renal failure, retinal hemorrhages and exudates with or without optic nerve head swelling.

New Definition and Guidelines

The American College of Cardiology recently published the 2017 Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. See Table 1 below for the revised BP categories.

Table 1.

Highlights of the New Definition and Guidelines

HTN is now defined as readings of 130 mm Hg and higher for the systolic BP measurement, or readings of 80 and higher for the diastolic measurement. That is a change from the old definition of 140/90 and higher, reflecting complications that can occur at those lower numbers.

In the first update to comprehensive U.S. guidelines on HTN detection and treatment since 2003, the category of prehypertension is eliminated.

While about 14 percent more people will be diagnosed with HTN and counseled about lifestyle changes, there will only be a small increase in those who will be prescribed medication.

By lowering the definition of HTN, the guidelines recommend earlier intervention to prevent further increases in BP and the complications of HTN.

The Bottom Line

Blood pressures that we in the past thought were normal or so-called ‘pre-hypertensive’ actually placed patients at significant risk for heart disease and death and disability. The eye is unique in that it allows direct observation of hypertensive consequences of the microvasculature in vivo. These ocular changes are of value in the management of systemic complications due to HTN, including diabetes, cardiovascular, cerebrovascular and other systemic vascular diseases.

For further reading on this topic, visit http://www.acc.org/latest-in-cardiology/ten-points-to-remember/2017/11/09/11/41/2017-guideline-for-high-blood-pressure-in-adults.