Who is a good candidate for lateral canthoplasty? It depends on whether the shortness of the eye's horizontal width is on the inner or outer side

Lateral canthoplasty is more likely to be suitable for people whose eye width shortness is on the outer corner side, and for whom widening the outer corner outward would noticeably change their appearance. If the fold at the inner corner of the eye (epicanthal fold) or weak eyelid opening is the main cause, widening only the outer corner may not produce the expected change. There is a limit to how much the outer corner can be widened, and there are risks such as misalignment of the outer corner and exposure of the inner mucous membrane of the eye.

Is the small appearance of the eyes due only to the outer corner?

Not necessarily. The small appearance of the eyes can be caused by the fold at the inner corner, weak eyelid opening (ptosis), or shortness on the outer corner side[1]It has been reported that the fold at the inner corner appears in approximately 40% of Asian people[2].

Even in treatment guidelines for congenital narrow eye fissure syndrome, it is recommended to combine 2–3 of the following procedures: surgery on the inner corner, surgery for drooping eyelid, and surgery on the outer corner[3]Eye size is often determined by several overlapping factors, which is good to keep in mind.

With lateral canthoplasty, how much wider does the eye become?

There are reports indicating that the horizontal width of the eye widens by 3–6 mm.[1]However, this figure was presented in a study where AI selected surgical candidates, not as a result of long-term follow-up of many people who underwent lateral canthoplasty.[1].

Historically, the procedure to widen the lateral canthus horizontally and the procedure to lower the lower eyelid and widen the eye vertically have been performed separately in two sessions.[4]Methods to perform both in a single session have also been reported.[4].

How does this differ from medial canthoplasty?

The location being widened is different. Medial canthoplasty removes the fold at the medial canthus, widens the horizontal width of the eye, and brings the eyes to an appropriately closer distance.[2]Lateral canthoplasty is a procedure to extend the lateral canthus outward.[1].

If the medial canthus is obscured by the fold at the medial canthus, medial canthoplasty is considered; if the lateral canthus side appears short, lateral canthoplasty is considered—the approach matches the cause. If both factors overlap, they may be combined.[3].

Who should think carefully before having this procedure?

People who are sensitive to changes in the shape of the outer corner of the eye. Papers on lower-eyelid surgery note that Asians tend to dislike eyes that appear pulled upward or small, and many dislike that lifting the outer corner of the eye makes the lower-lid love band less noticeable.[5].

Outer-corner incision is also said to be a procedure where reactions differ from person to person.[6]It helps to have a concrete image of the final result, including the angle of the outer corner of the eye after widening and how the lower-lid love band will appear.

What risks are there?

Scarring, misalignment of the outer corner of the eye, and the inner mucous membrane of the eye (conjunctiva) becoming visible from outside are noted.[6]Though rare, cases have been reported in which a small hole (fistula) formed in the conjunctival sac after outer-corner incision.[6].

Understanding the risks and asking in advance how much to widen the eye and how the outer-corner mucous membrane will be handled is the quickest way to reduce anxiety about the final result.

What does research still not understand?

Within the range of our search, we found no long-term studies of outer-corner incision for cosmetic purposes across many people. Reports of complications are mainly case reports.[6].

For this reason, questions like 'how much will it widen' and 'how much will it narrow back' must be judged by combining your physician's experience-based explanation with your own assessment of your eye shape.

What to confirm before having the procedure

There are three benchmarks to consider. First is identifying whether the cause of small-appearing eyes is at the inner corner, the opening of the eyelid, or the outer corner.[1][3]Second is how much you want to widen it, and changes to the outer-corner angle and lower-lid love band.[5]Third is your perspective on the risks of scarring and visible mucous membrane.[6].

How much room there is to widen your own outer corner cannot be decided by an article alone. Have a physician examine your inner and outer corners, your eyelid opening, and confirm this with you.