It looks like you have been given a few good leads in this thread. However, not meaning to split hairs, but do be aware that (to my knowledge) there are no "registered" veterinary opthalmologists in HK. There are a few vets with a very decent background in opthalmology (such as the ones mentioned in this thread, and quite a few more), but sadly none are specialists (yet!). In saying that, almost all eye cases can be dealt with by the talent in HK, and as I mentioned before, we do get a visiting/touring specialist coming over to see "special" cases.
When it comes to finding a "good" vet, there are a lot of things that need to be taken into consideration. Most important of all is who you like. Most vets are just as capable as the next - it seems to be more related to personal choice who you call a "good" vet.
Generally speaking, find a practice that is convenient to you, and that you like. If they cannot deal with something, they will refer you to someone who can.