The Eyes are the Windows to our Health
The eye is a fascinating structure and a marvel of human development. The crystal clear cornea allows light to enter the eye, where it passes through the pupil, through the central vitreous gel, ultimately to strike the back wall of the eye -- the retina. There, a complex signal is generated and transmitted to the brain where an image is formed... and we then see.
Interestingly, the eye is the only area of the body where microscopic blood vessels called capillaries, can be clearly visualized. This property of the human eye allows us to use it as a window to search for systemic diseases.
Of course, not every disease has ocular manifestations. However, many diseases do and thus the value of a comprehensive eye exam as a screening method for disease should not be underestimated. Consider these facts:
*Diabetes, a common disorder of sugar metabolism, can cause intraocular hemorrhages and may lead to glaucoma. Of note, retinal changes may be the only sign of diabetes in a non-symptomatic person.
*Hypertension or high blood pressure can severely narrow the retinal arteries leading to blockage of the ocular circulation and a stroke of the eye.
*Cardiac and carotid artery disease can lead to particles of cholesterol and calcium making their way into the retinal circulation, causing an ocular stroke.
*Blood-borne diseases such as severe anemia, leukemia and infections can present with characteristic eye findings which would allow the ophthalmologist to diagnose such abnormalities.
*Tumors of the central nervous system often produce visual symptoms along with swelling of the optic nerve. This swelling, called papilledema, is a hallmark of increased pressure in the skull. Certain lung tumors can affect the normal function of the pupils and can be discovered with a simple eye exam.
*Inflammatory diseases such as systemic lupus, temporal arteritis, rheumatoid arthritis, ulcerative colitis, Crohn's disease, multiple sclerosis and sarcoidosis can produce ocular inflammation which would prompt the ophthalmologist to search for these diseases.
*Systemic infections such as toxocara, syphilis, cat scratch disease, tuberculosis, chlamydia and gonorrhea (and others) can first present as an ocular infection.
Although the above list is not exhaustive, one can get a good idea how important the eyes are in evaluating a person's overall health and well-being. There is more to a routine eye exam than just a new pair of glasses.
