a song of ice and fire - Do Oriental-style civilisations exist in A Game of Thrones

We already know from the books that there are cities such as Yi Ti and Asshai to the far east that have not yet been explored in canon. Already a lot of cultures in ASOIAF have similar real-world analogues. Westeros is clearly modeled after Britain during the War of the Roses, with the exception of Dorne, which has a much more Mediterranean feel to it. The free-cities, with their constant warring and trading, remind us of the Italian city-states, or perhaps the German duchies and principalities of the Holy Roman Empire. Farther east we see the Mongolian influence of the Dothraki, with their love of horses, pillaging, and the vast steppes. Then there is Qarth to the south, with a bit of a middle-eastern/silk road analog to it. And of course, Slaver's Bay, which has a mix of Egyptian/Babylonian in it.

So, forgive me for a bit of inference, but with names like "the Jade Sea","Yi Ti", and "Asshai", it seems likely that even further east of the known-world we would begin to encounter far-eastern civilizations. Of course, these places may never play a role in the plot of the story. GRRM wanted to create far-off civilizations that seemed foreign and exotic, so even the locations of these places is still relatively vague.