Wow! How many years has it been since we've seen each other? You haven't changed a bit!!
Oh my goodness! It's been so many years. You still look the same!!
この場合、次のような言い方ができますよ。
ーWow! How many years has it been since we've seen each other? You haven't changed a bit!!
「わあ！会うの何年ぶり？全然変わってないね！！」
How many years has it been since we've seen each other? 「最後に会ってから何年経った？」＝「会うの何年ぶり？」と言えます。
ーOh my goodness! It's been so many years. You still look the same!!
「わあ！久しぶり。変わってないね！！」
ここでは、It's been so many years.「何年も経った」と言うだけで「ずっと会ってない」というニュアンスになります。
ご参考まで！
カナダ 
