By Dr S.S. Gill
Ipoh Echo’s EYE HEALTH series continues with Consultant Eye Surgeon Dr S.S. GILL talking to us about high blood pressure effects on the eye.
High Blood Pressure, also called hypertension is a condition where the force of the blood against the walls of the blood vessels (arteries) is high for a prolonged period resulting in health problems such as heart disease, kidney disease, hardening of the arteries, strokes and eye damage. When eye symptoms occur, it generally means the hypertension is advanced. The symptoms may include blurring vision, double vision, blood headaches or even sudden loss of vision.
The World Health Organization (WHO) estimates that 40% above the age of 25 years have hypertension. Globally, more than 1 billion people suffer from hypertension, also called high blood pressure.
When there is uncontrolled hypertension, the blood vessels in the eye start to thicken and progressively become more narrow. This restricts the blood flow from reaching the nerve (retina – picture on left) making it swollen and sometimes causing eye strokes (vessel occlusion) in the eye. This is called Hypertensive Retinopathy. In the more severe and dangerous form, it is called Malignant Hypertension, where it can cause profound blurring vision or even sudden loss of vision.
HOW YOUR EYES ARE CHECKED
In order to have a nerve (retina) check, eye drops will be first instilled in order to dilate the pupils. Then, using an instrument called an ophthalmoscope, light is passed into the eye in order to view the back of the eye. The eye examination is painless but may cause discomfort after the eye examination, due to glare if you have forgotten to bring a pair of sunglasses. In some centres, a retinal imaging device or fundus camera is available for nerve (retina) imaging.
THE SIGNS LOOKED FOR
Doctors evaluate and grade Hypertensive Retinopathy on a scale of 1 to 4. On the lower end of the scale, hypertensive retinopathy may not have any symptoms. In the more severe stage of grade 4, the eyes have a swollen nerve (optic nerve) and serious profound vision problems. This stage is dangerous and indicates uncontrolled hypertension. People with grade 4 retinopathy have a high risk of general systemic complications.
Prompt diagnosis of hypertensive retinopathy is important in order to avoid visual and systemic morbidity such as heart disease, strokes and renal disease. If you suffer from hypertension, it is advisable to get your eyes checked at least once a year before eye symptoms appear.