I often get asked how different diseases of the body affect the eyes and why it’s important to
have annual comprehensive eye exams even if you have perfect vision. So I thought I would
talk about the more common systemic diseases and their impact on the eyes.
Hypertension (High Blood Pressure) affects over 50 million Americans but few people know
how it can affect the eyes. When your blood pressure becomes elevated, your retina (located
in the back of your eyes) can start to develop small flame-shaped hemorrhages. If left
untreated, it can do enough damage to cause strokes and aneurysms in the blood vessels of the retina which can lead to loss of vision or even blindness. This is known as Hypertensive
Retinopathy and it is only visible by dilating the eyes or taking a wide-angle digital scan of the
back of the eye. The severity of damage to the retina is a good indicator of how poorly
controlled a patient’s blood pressure has been recently.
Hyperlipidemia (High Cholesterol) cause plaques to form in the tiny blood vessels in the
back of the eye causing ischemia (reduced blood flow). If those blood vessels get completely
blocked, the retinal tissue which is served by that vessel can die off and the vision lost to that
section of your eye. Sometimes the blockage can cause a large bleed in the retina from a
rupture of the vessel wall further damaging the surrounding tissue. Occasionally, the blockage
is behind the eye in the optic nerve and can also cause sudden and potentially permanent
vision loss as well. It is important to get your cholesterol checked annually if you are in an at
risk category (family history, poor eating habits, previous abnormal blood work results, etc).
Eye doctors will check the health of your retina either by dilation or a newer method using a
wide-field digital photo scan. Sometimes the cornea (front window of the eye) can also develop
white rings called “arcus” in the periphery which people often confuse with cataracts. So if you
start to notice a slow greying out of the color in your eyes, have it checked out.
Retinal damage from Diabetes is the leading cause of preventable
blindness worldwide. Diabetic Retinopathy is usually present in nearly 100% of all Type 1
diabetics and around 65% of Type 2 diabetics. The early stages usually present with what are
called “dot-blot” hemorrhages and are often accompanied by fluid and protein leaking out of
the blood vessels. Eye doctors may also notice unusually large fluctuations in your vision
prescription in a short amount of time. In the more advanced stages of damage, new leaky
blood vessels start to grow and can detach the retina causing blindness. Swelling of the macula
(the central retina) is what causes the greatest vision loss to your central vision when the
diabetes is severe. It swelling of the layers of the retina causing the vision to be blurred. More
severe cases of diabetic retinopathy are treated with lasers to try to limit the new blood vessels
formation and reduce the leakage, but long term only strict diabetic control of your blood sugar
will be able to keep your vision functional. Your eye doctor works closely with your
endocrinologist to make sure that each one knows what’s going on with the other in terms of
control, lab work, and retinal findings. So test your sugar often, and keep it controlled.
So the moral of the story is that diseases of the body can directly affect the health of your eyes so it's important to let your eye doctor check the health of your eyes every year. The best way to screen for a lot of damage is a digital scan of the back of the eye, such as an Optomap photo.