Infant pupil size

[b_rad_b]

My 7 month-old son was born with a left brachial plexus injury, after a somewhat difficult birth--he was pretty badly bruised. Since birth, I've noticed his left eye dilates to a lesser degree than his right. His right eye may appear a bit smaller and there is a single blood-vessel that is always visible on the outside of his right eye. I've spoken to pediatricians and our neurologists about this, and since both eyes seem to function normally, they've said not to worry and that it's not a Horner's. Also, the uneven dilation seems to becoming less noticeable as he grows.

Should we have this looked at? Any other advice or things to look for?

Thanks!

[Michael J Kutryb, MD]

The blood vessel doesn't bring much to mind - may be not much to worry about.  A smaller pupil can be a significant finding and Horner's Syndrome was the first thing that came to mind.  I'm not sure what to make of the "smaller" right eye.  I suggest you see a pediatric ophthalmologist for evaluation.  Thinking outside the box, there is always the possibility that the right eye with the larger pupil could be the abnormal one (such as rare third nerve palsy.  As usual the main things to worry about are strabismus (or eyes that aren't straight), amblyopia (or a lazy eye) and serious refractive errors.

MJK MD