Do not be alarmed if your eye doctor asks when you last had a colonoscopy. When your eye doctor dilates your eyes during a comprehensive exam, they take high resolution photos of your retina with advanced equipment such as an Optomap. When dark pigmentation shows up in the retinal photography it could signify cancer, or Gardner Syndrome. Gardner Syndrome, a systemic disease is a condition in which multiple, dark areas of pigmentation form in the retinas of the eyes and in rare cases these lesions may be associated with certain types of colon cancer. Many people underestimate the importance of annual eye examinations, not understanding that many diseases can affect the eyes, and that many diseases can be detected through their annual exam. “Systemic diseases are diseases that involve many organs or the whole body. Many of these diseases also affect the eyes. In fact, an eye exam sometimes leads to the first diagnosis of a systemic disease.”
According to the University of Illinois’ College of Medicine, some common system diseases that affect the eyes are Diabetes, Hypertension (or High Blood Pressure), AIDS, Graves’ Disease, Sarcoidosis, Lupus, Rheumatoid Arthritis, Atherosclerosis, Sickle Cell Disease and Multiple Sclerosis. However, the eyes may reveal other possible systemic illnesses such as different types of cancer.
The National Institute of Health (NIH) says that, “Gardner syndrome is a form of familial adenomatous polyposis (FAP) that is characterized by multiple colorectal polyps and various types of tumors, both benign (noncancerous) and malignant (cancerous). People affected by Gardner syndrome have a high risk of developing colorectal cancer at an early age. They are also at an increased risk of developing other FAP-related cancers, such as those of the small bowel, stomach, pancreas, thyroid, central nervous system, liver, bile ducts, and/or adrenal gland.” The NIH lists the presence of “congenital hypertrophy of the retinal pigment epithelium (a flat, pigmented spot within the outer layer of the retina)” as one of the possible manifestations of Gardner Syndrome. Congenital hypertrophy of the retinal pigment epithelium, often abbreviated as CHRPE, is one of the things your doctor screens for during your dilated eye exam. Although they don’t affect your vision, multiple lesions of CHRPE in both eyes are “strongly associated with familial adenomatous polyposis coli.”
However, most forms of CHRPE are benign. It is up to your eye doctor to evaluate the lesions based on the number of them, if they are present in one or both eyes, their shape and the regularity of the lesions’ borders. CHRPE associated with Gardner syndrome are usually present in both eyes, in multiple quadrants (or parts of the retina), they have a distinct, pisiform or peapod-like shape and have irregular borders.
If your eye doctor suspects you may have CHRPE associated with Gardner syndrome, they may refer you for a complete gastroenterological work up. The gastroenterologist will then decide what needs to be done next. Sometimes genetic testing will be performed, or a colonoscopy may be recommended. Colon cancer is just one of the forms of cancer that may be detected through an eye exam. Scheduling annual eye exams is one of the ways you can be proactive with your health.