We did 'before and after' diagnostic visits with vision therapy, so I've seen huge changes. Lingering issues? Nothing so far - I'm hoping that driving won't be a challenge.
In the intervening year (4th grade) DS got on a 'wall ball' kick at school on the playground, and I think that's what casued the big change. The dept perception scores really changed dramatically from 5th percentile to 50%. And DS's reading was always 'way above grade level' once he got to 2nd grade - the Optomitrist said he was at a 12 grade level. But his reading was never anywhere near as advanced as his listening to written words level. I love audio books, and we listened as a family to long involved stories, such as Ender's Game, as well as the shorter 'pearls' such as 'Stargirl.'
OTs should be able to do some of the same things as vision therapists. For DS15, I think it was just part of his 'asynchronous development: Normal eye abilities for age (low end of normal) and way above normal reading interest and phonological ability for age.
Still - knowing what I know now, I don't think I would have let my 'snake oil' squeamishness and the cost hold me back. What I'm hearing currently is that it is very very helpful for about half the families who try it.
Going for a diagnositic work up can be very difficult if you don't intent to follow up, but it's nice to have something objective to go on. We did a few other things, like the Nintendo DS game 'Brain Age' and the information did persuade me to start allowing DS to play 'first person shooters' sooner than I otherwise would have.
Best Wishes,
Grinity
