Lateral canthoplasty (outer corner surgery): techniques, risks, and research

What is lateral canthoplasty?

Cosmetic lateral canthoplasty is described as surgery that makes the eyes look larger by lengthening the eyelid opening (palpebral fissure) at the outer corner and reducing the upward slant of the eye, and it is widely performed in East Asian patients ^[1].

Operations that make the eyes look larger and more defined include double eyelid surgery, medial epicanthoplasty (inner corner surgery), and lateral canthoplasty (outer corner surgery). Double eyelid surgery is described as changing the eye vertically, while inner and outer corner surgery change it horizontally ^[2]. The difference is that inner corner surgery works on the inner corner of the eye, whereas lateral canthoplasty works on the outer end ^[2].

Who is it considered for?

One review explained that when the outer corners of the eyes slant upward and the eyes are short horizontally, adjusting the slant of the eyelid opening with lateral canthoplasty can widen the eyes and soften the overall look ^[2]. The authors described their own method of increasing the angle of the outer corner and correcting the outer end of the eye to soften a severe look ^[2].

The same review noted that, depending on the patient, it is sometimes combined with other procedures such as double eyelid surgery, inner corner surgery, creating an under-eye roll (aegyo-sal), fat grafting, or facial bone contouring ^[2]. However, which combination is needed depends on the structure of your eyes and face, so it should be decided through an individual examination.

Common problems and ways to reduce them

Complications and unsatisfying results after lateral canthoplasty are reported to be not uncommon ^[1]. To reduce them, one group of surgeons devised a technique that preserves the angle of the outer corner (lateral canthal angle), and described the anatomy involved in the surgery along with ways to reduce complications ^[1].

A systematic review of the literature from 2012 to 2018 also described approaches that maintain the continuity of the eyelid margin to prevent deformity of the outer corner ^[3]. These used less visible incisions: 2 studies used an incision through the gray line on the eyelid margin, and 2 used an incision through the upper eyelid ^[3]. Because so few studies were reported, there is not enough evidence to judge which method is better.

The same review named measures to minimize eyelid malposition caused by surgery as a recent trend in eye-area surgery ^[3]. Even small changes at the outer corner of the eye can noticeably alter a person's look, so it is best to have the risks fully explained in advance.

Lateral canthal surgery for functional reasons

The name lateral canthoplasty is not used only for cosmetic surgery. To treat ectropion, in which the lower eyelid turns outward with age, surgeons resecure the outer corner of the eye to tighten the lower eyelid horizontally, using either canthopexy or lateral canthoplasty ^[4].

When the lower eyelid is very lax or the ectropion is severe, the lateral tarsal strip procedure is still described as the preferred method, while canthopexy through an eyelid incision can be used when laxity is milder ^[4]. Functional surgery like this aims to tighten the eyelid, so its goal differs from cosmetic lateral canthoplasty, which widens the eye horizontally.

Outer corner surgery for congenital conditions

In blepharophimosis-ptosis-epicanthus inversus syndrome (BPES), a rare congenital condition in which the eyelid opening is narrow and the eyelids droop, operations such as inner corner surgery, lateral canthoplasty, and frontalis suspension are also used ^[5]. For this condition, surgery is considered the standard treatment, and an important goal is to restore eyelid function and improve the field of vision ^[5].

This systematic review concluded that complication rates vary with the technique and patient factors, that the choice of method should be tailored to each person, and that more prospective studies are needed to standardize surgery and reduce complications ^[5].

Lower canthoplasty and what to ask during your consultation

Surgery to lower the outer part of the lower eyelid, commonly called lower canthoplasty, was not specifically covered in the research summaries used for this article. As a result, this article cannot give any figures on the effects or complications of lower canthoplasty.

The results of outer corner surgery, including lateral canthoplasty, vary with the structure of your eyes and the look you want, and there are reports that complications and disappointing results are not uncommon ^[1]. We recommend checking the following points during your consultation.

• Whether lateral canthoplasty is needed given the structure of your eyes, such as the slant of the outer corner and the horizontal length of the eye
• How the angle of the outer corner and the eyelid margin will be preserved
• Whether it needs to be combined with other eye surgery
• Expected complications and what happens if you are not satisfied with the result
• If lower canthoplasty is also being considered, the evidence and risks behind it