Why do I need a dilated medical eye exam?

By Dr. Jean Keamy

Many of my patients have no eye complaints and only need glasses or nothing at all. Through an un-dilated pupil, a limited view of the optic nerve, blood vessels and macula can be obtained. The peripheral retina and optic nerve details cannot be thoroughly examined without dilation.

Some patients have family history, medical issues, complaints or concerns that require dilation of the pupil for a thorough eye exam. Most commonly any history or current complaint of floaters or flashing lights makes a dilated exam necessary. Those symptoms can be warning signs of a retinal hole, tear or retinal detachment. The peripheral retina must be examined carefully.

Any family history of glaucoma or high pressures in the eyes requires an examination of how large the optic nerve cup and a thorough examination of the optic nerve’s nerve fiber layer. Such an exam can only be performed with dilation.

Macular degeneration can present as very subtle changes in the macula. It is recommended that if macular degeneration runs in one’s family, or patients are over 55, they should have at least one dilated exam every year or two.

Hypertension and diabetes can affect the blood vessels in the retina. Anyone with this disease should have an annual dilated exam to look for abnormal blood vessel growth, blood vessel leakage, and retinal swelling.

Cataracts are extremely common in patients over 60. Since there are several types of cataracts, the subtle changes in cataract development can only be observed with a dilated eye exam.

Dilation of the pupils is inconvenient. The exam takes longer because the drops need 20 to 30 minutes to work. Afterwards, they can make both distance and near vision blurry for several hours. Many people prefer to bring a driver for these exams.