I am a rising 4th year med student going into ophtho, and I have been trying to gather the same info. Here's what I have come up with...
Avg step 1 score of those who matched in Ophtho = 228
Avg step 1 score of those who didn't match in Ophtho = 208
Now, I've also heard that Iowa (a top 10 program) had over 50 applicants with step 1 score >250. So, my take on the whole deal is that if you want to get noticed by a top program you either have to score above 250 on step one, or be AOA and in the 240's, or be a nobel laureate in Retina transplant with scores in the 230's. I really don't know if that is the case or not, but it seems hard to imagine a program director considering too many applicants with scores below 240, if s/he has got an overabundance of 250+ applicants.
But, remember that you can get good (or even better) clinical training from many of the sub "top 10" programs, and with ophtho being as competitive as it is, it is an honor to even match in the field. Just my take. Hope it helps.