Most patients do not want their eyes dilated during their eye exam. What many patients do not realize is that I get a much better view when the eyes are dilated. This helps me see things that I would not otherwise see. For example, in February 2014 I found a choroidal melanoma, a cancerous tumor at the back of the eye, in a first time patient who had 20/20 vision and no symptoms. She had no history of any type of cancer. The records from the prior exam a year before showed the same lesion but a bit smaller. That doctor did not dilate and instead relied on an instrument that takes a picture with a large field of view but the image is still in two dimensions versus the three dimensional view I get during a dilated fundus exam. I remember when I was performing the dilated fundus exam on this patient and saw a white area, saying to myself, “That looks elevated.”
For more information go to http://www.eyecancer.com/conditions/3/choroidal-melanoma
When I evaluate the optic nerve for glaucoma, the cupping of the nerve is more readily observed with a dilated pupil. Glaucoma is a disease that can cause blindness without any symptoms in the early stages. So the sooner we start treatment, the better chance of preventing blindness.
We typically dilate on the first visit, if there are any symptoms or history that suggest dilation and again routinely based on the age of the patient: every 4-5 years under 40, every 2 years 40-60, and yearly over 60. We are one of the few offices that have dilation reversal drops, which bring the eyes back to normal in 1-2 hours.