What signs in an eye exam are linked to brain tumors?

[lalllil]

Hi,
My 10 month old son has started seeing an opthamologist due to having eyes that turn inwards with one side being much worse than the other. So far he has had two appointments. Several people have done assessments on him on each visit and give their opinions as it is a learning hospital. In the end however there is one person who makes the final decisions. So far, all I know is that after two weeks of patching the good eye, there has been significant improvements in the functioning of the lazy eye. On the first appointment it was ordered that he have an MRI to rule out brain tumor. He had his second assessment two weeks later before the MRI was scheduled to take place. During this appointment it was questioned by a couple of people assessing him whether or not the MRI was still necessary based on their new findings. The Doctor that makes the final decisions seemed uncertain as to whether or not we should cancel the MRI. I told her that I would prefer to not do it if there was no longer any  evidence to suggest a possible tumor. In the end she ended up canceling the MRI. I have no idea what exactly it was in the first exam that they saw or didn't see that made them want the MRI and now in the second made them feel okay with canceling it. I won't be seeing the opthamologist again for a few weeks and am anxious to know what the signs are during an eye exam that makes a doctor want to rule out a brain tumor so I can look for these signs myself in the mean time. I just didn't feel that the doctor was completely confident in her decision to cancel the test and would really appreciate knowing more.
FYI:
-Baby had crossed eyes intermittently since birth
-There is a family history of this type of eye problem (grandfather.)
-My first ultrasound in my pregnancy there was indication of a cyst on the brain. The next ultrasound said it had gone away as expected.

[Houman Vosoghi, MD]

Unlikely it would be a brain tumor given what you describe (family history, with crossing since birth) but any atypical signs would push the pediatric ophthalmologist to order an MRI to be sure.  Hard to describe the findings that would be "classic" of a brain tumor as they could present a lot of different ways.  In most cases of eye crossing or strabismus in this age group though, most doctors don't order MRIs unless something seems "different."  You may want to ask them what features in your child's case made them think about the MRI.  You could read about Esotropia on line (there are different types) and the usual exam findings that you should expect but no way for you to check for these yourself without a deep knowledge of the subject matter or the appropriate equipment and even describing them is very difficult given the amount of knowledge required to understand all the features.

HV

[Jesica5]

A related discussion, why did the opthomologist order an MRI for my son? was started.