High blood pressure falls into peripheral vascular disorders, and is defined as blood pressure of 140/90 mmHg for at least two times.
The main reason why blood pressure rises is unknown; however, some factors increase the risk of developing high blood pressure. These predisposing factors are heredity, gender, age, race, obesity, salt sensitivity, alcohol consumption, oral contraceptive pills and sedentary life.
Classification of High Blood Pressure
High blood pressure is classified into primary and secondary types:
In primary hypertension, the cause cannot be determined as it appears gradually.
In secondary hypertension, underlying conditions cause blood pressure. As such, blood pressure emerges suddenly. For example, kidney diseases, adrenal gland tumor, oral contraceptive pills, decongestants, or drugs like cocaine and amphetamines fall in this category.
High blood pressure has no symptoms in most cases; many people are unaware of their high blood pressure for years, take no action to treat it, and suddenly realize they have it.
Ocular Manifestations of Hypertension
High blood pressure leaves destructive impacts on the ocular system and makes the treatment complicated, costly and sometimes impossible. The most important complications of hypertension occur in retina; while other parts of the eye are not spared, e.g. a sudden rise in the blood pressure, especially in young people can cause changes in the vessels and choroidal pigments, though it has no special effects on vision. Moreover, acute increase in blood pressure can sometimes rupture delicate conjunctival vessels and even cause subconjunctival hemorrhage; of course, this bleeding is commonly absorbed within weeks and needs no special treatment.
It is noteworthy that in people with diabetes, hypertension can exacerbate complications of diabetes in retina (diabetic retinopathy). Therefore, since controlling blood pressure in diabetic people is highly important, it should be taken seriously.