First, the fundamental concepts differ: "eyelid surgery" refers to inner canthoplasty. Inner canthoplasty does not truly "open" the inner corner; it merely releases the epicanthal fold covering the inner canthus to reveal underlying structures. Outer canthoplasty is entirely distinct—it genuinely opens the lateral canthus, a specialized and critical anatomical structure. This procedure alters the unique outer canthus architecture, making restoration difficult.
Outward canthoplasty often yields unsatisfactory results due to several drawbacks: even if enlargement is achieved, the lack of a three-dimensional eyelid margin and eyelashes makes the appearance unnatural. The effect is further limited by the constraints of the orbital bone structure. The thin conjunctiva is difficult to manipulate and prone to retraction and adhesion, frequently leading to conjunctival ectropion.
In summary, inner canthoplasty is more widely accepted and more readily achieves the desired larger eye effect with excellent postoperative results. Outer canthoplasty demands high technical proficiency from the surgeon. Therefore, if you are considering outer canthoplasty, it is essential to select an experienced plastic surgeon to ensure satisfactory outcomes and minimize postoperative complications.