A nose bridge threadlift will offer a mild improvement if you have prominent medial epicanthic folds. This is because the threads inserted adds volume to the nose bridge area and stretches the skin, resulting in a medial pull of the medial epicanthic folds.
That being said, the effect is temporary, as are nose threads, lasting for 1-2 years, and is normally quite limited. Unless your nose bridge is your primary aesthetic concern, it might be in your interest to consider a medial epicanthoplasty.
Hope this helps!