"could this be the beginning of some kind of dystrophy?"
possibly. but it would be really hard to detect "early" distrophy. no, no other signs that would "alert" the doc.
it is possible that you are being paranoid. it is also possible that you have the "beginning" of something. who knows?
but retinal specialists are adept at looking for ANY retinal changes. if there was something there, he'd have found it. he's looking for (and apparently not finding yet) way more things than you think he is.
if you were seen by a retinal specialist and he didnt find ANYTHING, then its unlikely that there's any problem there.
here, i have only had two dilated exams and still nothing ..
the doctors here seem reluctant to do further testing, in the absence of any findings on the dilated exam ...
would you expect that over the course of eight years, if there was something weriously wrong, they would have found something?