How much can canthoplasty change the eyes? What's possible and what are the limits

Canthoplasty is a surgery that cuts the epicanthal fold (mongolian fold) covering the inner corner of the eye to widen the visible inner area of the eye. You can expect changes such as making the eyes appear slightly larger and bringing the appearance of the distance between the eyes closer together. However, there are individual differences in the thickness and shape of the fold, and it is not suitable for everyone. Removing too much can result in unnaturally round eye corners or noticeable scarring[1]。

What does canthoplasty do?

Canthoplasty, also called medial canthoplasty, is a surgery that processes the epicanthal fold and reshapes the inner corner of the eye. By cutting the skin and replacing the tissue or removing excess skin, the inner angle of the eye hidden by the fold is revealed[2]。Some reports indicate that when performed together with Double eyelids surgery on the upper eyelid, the force on the scar is distributed, making scar formation less likely[2]。

What's possible? Expected changes

What you can expect is a slight widening of the horizontal width of the eye and easier creation of parallel-type Double eyelids[3]。In methods combined with upper eyelid surgery, it has been reported that it becomes easier to connect the Double eyelids line to the inner side while adjusting the indentation on the canthus side[3]。On the other hand, the magnitude of change depends on the original condition of the fold. Not everyone will experience the same amount of widening.

What can't be done? Who is it not suitable for?

Canthoplasty is not a surgery to remove Sagging (skin laxity) of the entire eyelid or to change the vertical size of the eye. For people with thin folds or those whose eye corners already protrude, the changes obtained may be small. Guidelines also state that caution should be exercised for people who may have difficulty accepting scars at the eye corner or changes in facial impression[2]First, identifying what type of fold you have and whether it will change with surgery is the starting point.

What's different about the surgical techniques?

Representative techniques include Z-plasty, which exchanges skin flaps; W-plasty, which makes a zigzag incision to make scars less noticeable; and skin redraping, which minimizes skin incision and repositions the upper eyelid. [4][2][4]Z-plasty and W-plasty are based on the concept of local flap techniques that disperse a single-line scar to make it less noticeable.[4]Which technique is suitable depends on the thickness of your fold and your desired inner-eye shape.

Scars and relapse: Risks you should know about

The most important concern with inner-eye incision surgery is scarring.[1]Since the surgical design and technique choice directly affect how much scarring remains, where and how to incise are important considerations.[1]There can also be variation in results, such as asymmetry between the eyes or less/more widening than expected. Since it's difficult to reverse over-correction, a physician's approach of conservative design and staged thinking becomes a factor in your decision.

If you're unsure, what should you have examined at the consultation?

The deciding factor is whether your Mongolian fold is a thick type or a type with strong pulling force. Since self-assessment is difficult in the mirror, have the shape of your fold and skin thickness examined at your consultation, and get a full explanation of which technique is appropriate and how much scarring will remain and where. Rather than simply enlarging the eyes, make sure to confirm at the consultation whether you can decide on a design that suits your eyes together.