Hi-
Any veterinary ophthamologist that works on small animals will be able to help you. From the American College of veterinary Ophthalmology website, there is a link to search by state for members, and 4 vets come up for the state of MO.
http://www.acvo.org/locate_an_ophthalmologist.htm
Not sure if any of these are local to you, but they may also know of any general practitioners who could help you. This would be your best source of info.
Best of luck with your dog,
Christine
Veterinary Technician
Licensed veterinary technician (B.S. Mercy College), 10 yrs in animal medicine and training