10 Diseases Eye Dilation Can Spot

What your doctor can catch with an eye exam

During a dilated eye exam, your doctor can check for many different diseases, including some that have no early warning signs.

Here are some of the diseases and conditions your doctor can spot with a dilated eye exam:

1. Macular degeneration

This eye disease happens when aging causes damage to the part of the eye that controls sharp, straight-ahead vision, leading to vision loss and possibly blindness. Catching it early can allow for treatments that can slow its progress.

2. Glaucoma

Because glaucoma often has no symptoms, many people don’t know they have it until it causes significant, irreversible vision loss. Although there is no cure for glaucoma, if it’s caught early, there are treatments that can preserve treatments and prevent vision loss.

3. Cataracts

Dilating your eyes makes it easier for your doctor to check for early signs of cataracts, a slow clouding of the eye’s lens that makes it difficult to see, especially at night.

4. Diabetes

An eye exam can reveal damage to the blood vessels in the back of your eye, an early sign of diabetes. “We can see blood vessels in the retina better than anywhere else in the body,” Greenberg says. Diabetes is one of the leading causes of blindness in older adults.

5. High cholesterol

If your doctor sees a white ring around the edge of your cornea, that can be a sign of high cholesterol, which increases your risk of heart disease and stroke, says Sharon Fekrat, a professor of ophthalmology and a retina specialist at the Duke University School of Medicine.  

6.  High blood pressure

A dilated eye exam can reveal uncontrolled high blood pressure, which increases your risk of heart attack and stroke. During an exam, “the very small blood vessels look narrowed in the retina, and instead of looking red, they are slightly pink or silvery,” Fekret says. “They are also much narrower than we would expect.”

7. Sexually transmitted diseases

Syphilis, herpes, chlamydia, HIV, gonorrhea, genital warts and pubic lice can all affect layers of the eye. Untreated syphilis that shows up in the eye can lead to vision loss and even blindness. Herpes that has been dormant in older adults can appear in the eye if your immune system weakens, Greenberg says.

8. A brain tumor

An undiagnosed tumor can cause pressure to build up in the brain and cause changes to your optic nerve that your doctor can see.

9. Cancer

A leukemia reoccurrence is sometimes diagnosed through an eye exam, because leukemia cells tend to collect in the eye, Fekrat says. Breast cancer, prostate cancer and lung cancer can also affect layers of the eye.

10. Infections and inflammation

Bacterial infections sometimes show up in the eye as blood spots on the retina, especially if it’s an infection like acute endocarditis that affects the heart and blood vessels, Greenberg says. Rheumatoid arthritis and other inflammatory conditions can also affect the eye.