Avoiding regret with canthoplasty: Why regression and lower-lid ectropion occur

Regret after canthoplasty often stems from regression—where the widened outer corner returns to its original position—and lower-lid ectropion or mucosal exposure, where the lower lid turns outward. Regression causes patients to feel the effect was absent or that the eye actually became smaller, and ectropion is reported to lead not only to aesthetic concerns but also to dry eye. Large prospective studies following only this procedure are limited, so related surgical data are reviewed together.

What are common regrets after canthoplasty?

Four complications are frequently cited: distortion of the outer corner shape, regression, visible mucosal membrane on the underside of the lid, and lower-lid ectropion.[1].

Canthoplasty is positioned as one of the surgical techniques for Asian eyelid surgery[2]. However, without measures to preserve the outer corner shape, these complications become more likely to occur.[1].

What happens with regression?

The triangle of white of the eye visible on the outer side of the corner becomes smaller. As a result, patients may feel the surgery had no effect, or that the eye actually became smaller.[1].

The technique of re-fixating the outer canthus tendon may show increasing regression over time. In treatment studies of a condition where the lower lid retracts inward, success rates with this technique were 96.2% at 6 months and 88.5% at 12 months[3]. These figures are for reference only, as the goal differs from cosmetic canthoplasty.

What are the concerns if the lower lid turns outward (ectropion)?

It leads not only to aesthetic concerns but also to dry eye. Visible mucosal membrane on the underside of the lid and ectropion are reported to be both aesthetically concerning and a cause of dry eye.[1].

Special attention is required if concurrent lower-lid surgery is performed. Complications such as lower-lid descent, sagging of the outer portion, and ectropion are known to occur even with surgery performed from the inner surface of the lower lid.[4].

What if I combine this with other eyelid surgery?

Combining procedures increases the points to confirm. In a report of 400 people who underwent canthus tendon tightening surgery and upper and lower eyelid sagging removal simultaneously, recurrence occurred in 4%, temporary blood accumulation (hematoma) in 3%, and tearing in 3%[5].

Additionally, a difference in eyelid height between left and right was seen in 2%, and conjunctivitis or swelling in 1%[5]. Because this differs in surgical purpose from lateral canthoplasty (which widens the lateral canthus), the data cannot be directly applied.

How far is the data on this surgery understood?

Within the scope of our research, we found no studies tracking cosmetic lateral canthoplasty alone in large populations over a long period and presenting recurrence or ectropion rates. The numbers we can present are limited to data from similar procedures or surgeries with different purposes[3][5].

For this reason, we cannot accurately state what percentage of people will experience recurrence. It is reassuring to discuss with your surgeon on the premise that recurrence or ectropion can occur, and to ask about measures to take if they do.

Points to confirm during consultation

First is how the lateral canthus angle will be preserved and how fixation will be done to prevent recurrence[1]. Second is whether there is slack in the lower eyelid and preparation for ectropion[1][4]. Third is whether other eyelid surgery will be performed at the same time[5].

How far your lateral canthus can be widened depends on your eyelid tension and bone structure. Please confirm with your surgeon during the actual consultation, including the condition of your lower eyelid.