INTRODUCTION
Many women desire to have larger and brighter eyes. Many patients wish to obtain a
larger eye shape by lengthening the lateral canthal angle and, at the same time, a
brighter eye by correcting the raised outer tail of the eyes via lateral canthoplasty.
If the horizontal dimension of the palpebral fissure is short and the lateral canthus
is located higher than the medial canthus, it can give a stubborn, angry and unfavorable
impression.
There have been many misconceptions about lateral canthoplasty, including that (1)
after lateral canthoplasty, the patient's eye eventually returns to its preoperative
state as time passes, (2) a single operation is insufficient, and so multiple operations
are necessary, (3) a natural drooping of the outer tail of the eye occurs with aging
so that there is no need for surgery, and that (4) in order to prevent postsurgical
complications such as shrinkage of the lengthened lateral canthal angle, patients
must keep their eyes open, without closing them, and keep their outer eye area stretched
out. These misconceptions are so prevalent that not only patients but also plastic
surgeons tend to avoid cosmetic lateral canthoplasty.
Through experience with thousands of cases, the authors first presented "Cosmetic
lateral canthoplasty which lengthens the lateral canthal angle and simultaneously
corrects the raised the outer tail of the eyes using periosteal fixation" at the 10th
Meeting of the Association for Research on Minimal Invasive Plastic Surgery: MIPS
in April 2008. After that, the authors have given numerous presentations on surgical
methods at various conferences, symposiums and training lectures. To make the eyes
appear larger and brighter and to achieve a favorable impression, the authors conducted
lateral canthoplasty, which lengthens the lateral canthal angle and lowers the raised
outer tail of the eyes. In this paper, by introducing the authors' own method, the
authors intend to provide a guide and surgical tips to perform an effective cosmetic
lateral canthoplasty.
ANATOMY OF THE LATERAL CANTHAL AREA
There are three components of the lateral canthal area under the skin; the lateral
palpebral raphe (LPR), superficial lateral palpebral ligament (SLPL), and deep lateral
palpebral ligament (DLPL). The lateral ends of the superior and inferior orbicularis
oculi muscles interlace at the lateral commissure and form the LPR.
The lateral palpebral ligament is divided into the SLPL and the DLPL. The SLPL extends
from the lateral ends of tarsal plate to the periosteum of lateral orbital rim. The
DLPL extends from the lateral ends of tarsal plate deep into the origin of the SLPL
to Whitnall's tubercle on the zygomatic bone inside the orbital margin. It is located
deeper than the SLPL. The DLPL is attached to the lateral orbital tubercle (Whitnall's
tubercle). Whitnall's tubercle was located 2.9–0.8 mm inside of the orbital rim of
the zygoma [1].
When performing lateral canthoplasty, the SLPL must be incised and dissected to release
the lateral canthus, enabling an effective surgery. As the DLPL is deeply located
and difficult to find, there is no need to expend effort detaching or incising it.
SURGICAL PROCEDURES
Design
The design of the surgery is very simple. Following the crease around the lateral
canthus (A), the end point of the incision line (B) is marked ([1]
[2]). At this time, the end point should not go past the lateral wall of the bony orbit.
Marking the lowest point of the bony orbit will help to find a fixation point during
surgery.
Fig. 1 Schematic drawing of the operation, left eye
A & A', lateral canthus; B, end of incision; A'-B, new lateral canthus; ↓, lowering
of the slant of the palpebral fissure; the shaded area, enlargement after lateral
canthoplasty.
Fig. 2 Design of lateral canthoplasty
(A) Lateral canthus. (B) End point of incision.
Local infiltration
First, anesthetic eye drops (Alcaine 0.5%, proparacaine hydrochloride) are applied
to the eye. Using a 30 gauge 1/2 inch needle, an anesthetic containing 1:100,000 epinephrine
mixed with a 1:1 solution of 0.5% bupivacaine hydrochloride and saline solution is
injected.
Incision and dissection
Before beginning the operation, traction sutures are applied to the upper and lower
eyelids. A skin incision is then carried out from point A to point B ([Fig. 3A]). After incision and dissection of the LPR and the SLPL, the lower lid is pulled
lightly in order to check whether it has become sufficiently released. At this point,
care should be taken not to damage the DLPL through excessively deep dissection ([Fig. 3B]). A critical zone delineates a circle with a radius of 0.5 cm, and its center is
located 30° inferiorly and laterally, and 2.5 cm from the lateral canthus [[2].
Fig. 3 Incision and dissection
Incision (A) and dissection (B) during lateral canthoplasty.
Using a 6-0 nylon suture, canthopexy is performed at the periosteum and lower lid
([Fig. 4]). In order to produce a firm fixation, suturing is done at two places, and the point
of fixation should be made within 3 mm of the lower lid margin. When affixing to the
periosteum, a firm fixation should be placed at the inner side of the bony orbit's
lateral wall in order to prevent complications such as eversion of the lower eyelid
after surgery.
Fig. 4 Canthopexy
Canthopexy to (A) the periosteum and (B) lower eyelid.
Skin closure
A skin suture was placed using 7-0 black silk. As the area of surgery is close to
the eyeball, soft thread should be used in order to reduce irritation to the eyeball.
Factors to consider after surgery
After surgery, oral antibiotics and ophthalmic ointment, as well as three kinds of
eye drops (antibiotics, steroids, and artificial tears) are prescribed. Steroid eye
drops should only be used for a short period of time when the palpebral conjunctiva
is swollen. Care must be taken not to open or rub the wound.
While the patient may wash their face or take a light shower after removing the stitches,
they should wait for three weeks before going to a sauna or swimming pool and before
wearing contact lenses.
Postoperative progress
The stitches are removed five to seven days after surgery. Within one month after
surgery, swelling is reduced by more than 90%. Palpebral conjunctival swelling and
bloodshot eyes mostly disappear within three weeks. While the incision line can appear
red for about two to three months, as time passes, it blends in with the surrounding
skin color and is no longer noticeable.
Clinical cases
Case 1
A sub-brow lift, non-incisional double eyelidplasty, and lateral canthoplasty were
performed on a 51-year-old female patient ([Fig. 5]).
Fig. 5 Case 1
Preoperative and postoperative photographs of a 51-year-old female patient. A sub-brow
lift, non-incisional double eyelidplasty, and lateral canthoplasty were performed.
(A–D) Preoperative photographs. (A–C) Preoperative frontal view, three-quarter right
side view, three-quarter left side view (D) view of patient looking upwards. (E–H)
Photos six months postoperatively. (E–G) Postoperative frontal view, three-quarter
right side view, three-quarter left side view (H) view of patient looking upwards.
When the postoperative eyelash tattoo was compared with the preoperative eyelash tattoo,
the outcomes of the surgery were evident.
Case 2
Non-incisional double eyelidplasty and lateral canthoplasty were performed on a 23-year-old
female patient ([Fig. 6]).
Fig. 6 Case 2
Preoperative and postoperative photographs of a 23-year-old female patient. Non-incisional
double eyelidplasty and lateral canthoplasty were performed together. (A, B) Preoperative
frontal view, three-quarter right side view photos. (C, D) Frontal view, three-quarter
right side view photos one month postoperatively.
Case 3
A 35-year-old female patient who underwent lateral canthoplasty ([Fig. 7]).
Fig. 7 Case 3
Photograph of a 35-year-old female patient, postoperatively. Only lateral canthoplasty
was performed. (A, B) frontal side preoperatively, left side three-quarter view photos.
(C, D) 5 years and 4 months postoperatively, frontal view, three-quarter left side
view photos.
DISCUSSION
The horizontal dimension of the palpebral fissure in Koreans is 26.8±1.9 mm in men
and 26.1±1.9 mm in women, and the average slant of the palpebral fissure for men and
women over ten years old was 7.9±2.4 degrees in men and 8.8±2.3 degrees in women,
with a greater degree of incline showing in women than men [3]. Because many persons have a short horizontal dimension and raised outer tail of
the eyes, there are many patients who want cosmetic lateral canthoplasty.
Until recently, lateral canthoplasty had been performed mainly on patients with lower
lid malposition such as retraction, as well as lid laxity, ectropion, and entropion.
However, plastic surgeons as well as patients had been reluctant to perform or undergo
cosmetic lateral canthoplasty due to the many instances of extensive scarring or lack
of effectiveness in cosmetic applications for the lengthening of the lateral canthal
angle.
Shin et al stated the principles and guidelines for performing cosmetic lateral canthoplasty
as follows: (1) the continuity of the lower eyelid margin should be preserved, (2)
the contact surface should be kept fittingly between the bulbar conjunctiva and palpebral
conjunctiva, (3) the eyelashes should be saved, and (4) the patient's orbital condition
should be more than 4 mm from the orbital rim to the lateral canthal angle in exophthalmometry
[4].
In the authors' experience, the lateral canthoplasty is successful if (1) there is
plenty of space between the lateral canthus and the lateral bony orbital wall, giving
enough leeway for performing lateral canthoplasty, (2) the eye slants upward, (3)
the eye is exophthalmic rather than enophthalmic, (4) and the size of the eye is large.
On the other hand, surgery tends to be less effective when (1) there is a small amount
of space between the lateral canthus and the lateral bony orbital wall, making canthoplasty
difficult, (2) the eye is sunken in or (3) the eye corner slants downwards, (4) there
is a severe blepharochalasia, covering the lateral canthus, (5) the volume of the
bony orbit is small, or (6) the eye is small and (7) lacks a double eyelid.
An effective lateral canthoplasty can be achieved by performing horizontal lengthening
and vertical lengthening of the lateral canthal angle at the same time.
If the lateral canthus is simply incised and sutured, the effect of the lateral canthus
lengthening will be insignificant. In instances when the inner palpebral conjunctiva
is exposed, a red palpebral conjunctiva is visible, and when the skin flap is raised,
scarring may occur on the outer area of the lateral canthus. If incision to the outer
area is performed, avoiding the lateral canthus, complications may occur such as the
disappearance of the lower lid eyelashes during dissection, visible scarring of the
lower eyelid margin, or scarring in the shape of a notch appearing at the starting
point of the incision of the lateral end of the upper eyelid.
Depending on the postoperative presence of a gray line defect, we can classify lateral
canthoplasty by cases in which there is no gray line defect, where the gray line defect
is limited to the upper eyelid, where it is limited to the lower eyelid, and where
it is present on both the upper and lower eyelid.
It would be ideal to obtain good results from lateral canthoplasty without having
a gray line defect, but in actuality, this kind of lateral canthoplasty leads to poor
surgical results.
If a gray line defect remains at the lower eyelid, lower eyelid continuity is destroyed
and the eye shape appears unnatural or the palpebral conjunctiva is exposed, making
it appear red. In addition, the lateral rectus capsulopalpebral fascia is attached
at the lower eyelid tarsus, functioning as a lid retractor. Since a defect in this
can affect the functioning of the eyelid, it should be avoided as much as possible.
For example, if a gray line defect appears at both upper and lower lids, as in the
von Ammon method, there is a high possibility that scar contracture will occur, so
that the shape of the lateral canthus becomes rounded or the palpebral conjunctiva
is pulled taut, becoming exposed and appearing red.
While it is ideal not to have any gray line defect, if its occurrence cannot be avoided,
it is best for the defect to appear at the lateral end of the upper eyelid. This is
because, while there are ciliaeyelashes on the upper eyelid, there normally are not
any eyelashes within a few millimeters of the lateral end, and any eyelash defects
caused by lateral canthoplasty can be sufficiently hidden by the surrounding eyelashes
and slightly drooping skin. It is important that the continuity of the lower eyelid
be preserved. There should be no defect of the eyelashes on the lower eyelid.
The authors' own methods comprise canthotomy, cantholysis, and canthopexy. Not only
are these methods effective for lengthening the lateral canthal angle, it is possible
to correct the slant of the palpebral fissure at the same time. While a gray line
defect appears at the upper eyelid lateral end, it can be sufficiently hidden and
does not become a major problem.
During lateral canthoplasty, because lengthening of the lateral canthal angle is ineffective
in conducting cantholysis or canthotomy and suturing through a simple skin incision,
canthopexy is performed simultaneously. Canthopexy not only has good results in lengthening
the lateral canthal angle, it can also correct the slant of the palpebral fissure.
Canthopexy is performed using a 6-0 nylon suture, and at this time, fixation should
be done within 3 mm from the margin of the lower eyelid in order for the fixation
to be effective. Generally, the tarsal plates are semilunar shaped. They are of 3
types: symmetric, medially skewed, and laterally skewed. The skewed types are more
common than the symmetric type. The width of the upper lid tarsal plate is 9.3 mm
at its center, whereas the width of the lower lid tarsal plate is about 4.6 mm at
its center. The width of the medial 1/4 and the lateral 1/4 comes to no more than
3.9 mm and 3.8 mm, respectively [5]. As the lateral rectus capsulopalpebral fascia and the lateral canthal tendon are
connected at the lateral aspect of the tarsus [6], canthopexy should be conducted within 3 mm from the lower eyelid margin in order
to have solid results.
Taking the vectors of the canthopexy into consideration, fixation should be performed
inside the bony orbit in order to prevent postoperative eversion of the lower eyelid's
outer side.
There are three important techniques for creating a natural eye shape after lateral
canthoplasty: first, beginning the incision precisely at the lateral canthus; second,
performing a fixation at the inside of the bony orbit when carrying out canthopexy;
and third, precisely matching the lateral canthal angle when suturing the skin.
As the eyeball is round, it is important that the lower eyelid and the eyeball remain
in contact with each other after canthoplasty. When canthopexy is performed, fixation
should be performed at the inner area of the bony orbit, and if the lateral canthal
angle is matched well when the skin is sutured, then after surgery the eyeball and
the lower eyelid will be in proper contact and the eye shape will become natural after
surgery. There are congenital cases, though they are rare, in which the eyeball and
lower eyelid do not come into contact with each other, and since lower eyelid surgery
performed to correct entropion can result in the failure of the eyeball and lower
eyelid to contact each other, the surgeon must take this into consideration through
consultation and medical interviews.
Postoperatively, complications can occur such as conjunctival hemorrhage, conjunctiva
edema, and, uncommonly, dellen. Even in severe cases, however, recovery is possible
through two to three weeks of conservative treatment.
The lateral canthal angle borders the eyeball and is the place where tears flow. If
it is not properly managed, there is a high chance that wound dehiscence could occur.
For three weeks after surgery, care should be taken to avoid any impact to the site,
and not to open or rub the wound at all. The occurrence of dehiscence may result in
fish mouth-shaped scarring, which can be easily corrected through a simple scar revision
once scar maturation has completed.
CONCLUSION
While lateral canthoplasty by itself can provide sufficient results as a type of eye
surgery, it has a complementary character in that the results are even more prominent
in eyes with double eyelids. Changes mainly appear in the outer eye area. This surgery
is appropriate for patients who want a larger and brighter eye shape and want to achieve
a favorable impression by lowering the raised the outer tail of their eyes.
If this operation is conducted through the selection of suitable patients and the
surgeon is familiar with the surgical methods, the operation can be safe, reliable
and provide good results. Depending on the status of the patient, simultaneously performing
another operation that can make the eye large and bright, such as double eyelidplasty
or epicanthoplasty, can provide even better results.
