Canthoplasty refers to a more invasive surgical procedure than canthopexy. It focuses on the lateral canthus (the outer corner of the eye where the lower and upper eyelid meet) and surrounding supporting structures. The lateral canthus is located slightly above the junction of the upper and lower eyelids close to the nose (medial canthus). 

Causes of a loose, drooping lid include aging, previous poor cosmetic surgery (revision procedure), damage by the sun, excessive smoking and alcohol consumption, and skin cancer surgery.

Preparation & Expectation Before Surgery

Even though it's a one-day outpatient procedure, the patient should organize for transport home due to the slight pain and discomfort following the procedure. The oculoplastic surgeon assesses the eye’s anatomy by marking with a pen an area of the eyes where the incisions are to be made. The specialist carefully analyses the tone, position, lower lid function, overall facial structure, and lid laxity. Local anesthetic or intravenous sedation will be administered.

Type, Purpose & Procedure

The procedure is performed in conjunction with cosmetic eye surgery to reposition the lateral canthus. Canthoplasty’s purpose is to strengthen canthal tissues to maintain the standard position and relationship between the eyeball and eyelid. It can also be used in reconstructive surgery where the eyelid’s corner is strengthened due to drooping and sagging of eyelids, uneven eyelids, and under-eye bags. Canthoplasty is also used to treat eyelid malpositions, entropion (when the eyelid is turned in), or ectropion (when the eyelid is turned out). Profound eyelid laxity involving the lateral tarsal strip or previous blepharoplasty (eyelid surgery) can also be addressed by canthoplasty. 

It is usually a necessary lower eyelid reconstruction surgery after a lower eyelid or midface surgical procedure that did not go well. The procedure can be performed for both cosmetic (some patients desire a more almond-shaped appearance) and medical purposes. 

The 1-2-hour procedure varies from patient to patient. There are two main types of canthoplasty. In lateral canthoplasty, the oculoplastic surgeon aims to achieve eyes similar to a cat's while in an epicanthoplasty, the surgeon reshapes the eye's inner corner. The aim of canthoplasty altogether is to cut the lower canthal tendon and then tighten or reposition it. 

The surgeon makes an incision at the lateral canthus in lateral canthoplasty to detach it from the bone at the eye socket. S/he then shortens it and pulls the internal lower lid structure (tarsus) into a new position to support the eyelid. The oculoplastic surgeon uses sutures to reattach the tendon to the lateral orbital rim at the appropriate height. The surgeon then uses a special, clear plastic shield to cover the eyeball. The shield is removed after closure of the incisions. The oculoplastic surgeon dresses the eye to protect the wound and reduce inflammation.  

In epicanthoplasty, the surgeon makes a small incision in the inner corner of the patient’s eye. He/she will remove excess skin that causes a Mongolian fold and carefully stitch up the incision so as not to leave behind a scar.

Risks, Side Effects & Complications

Swelling, discomfort, and bruising can occur. Fluid can also collect over the sclera (white of the eye) but can be eliminated or minimized using a laser. Infections are rare but can occur. Another side effect is hemorrhage, which can affect eyesight.

A scar may form where the upper lid skin is incised in the lid crease; however, this disappears with time. More prominent scars and lid asymmetry, nevertheless, require modification. 

Complications involving canthoplasty are rare. The upper or lower eyelid muscle can be damaged, resulting in a droopy eyelid or double vision (due to damage to lower lid). Sometimes a patient may have trouble closing the eye if excess skin was taken from the upper eyelid. Another complication is that the lid can sit away from the eye in lower lid surgery due to swelling. However, this situation quickly resolves on its own.

After Care, Recovery & Outcome

The specialist will provide post-operative instructions, including follow-up appointments, which the patient must strictly adhere to. It is expected that inflammation may arise which can range from mild to severe. The patient should use a cold compress on the site for about two days after surgery. A little blood may ooze during the 24 hours after surgery, and this is normal. Bruises and soreness often occur after surgery but should go away in 7-10 days. Over-the-counter medications should help relieve pain and discomfort.

The patient should not bend or lift heavy objects or undertake any strenuous physical activity for ten days. The head should be elevated as much as possible, and the patient is advised to get as much rest as possible in the initial days following the procedure. The patient should avoid makeup and rubbing the surgical site for at least seven days. Other things to avoid include staring at the phone, watching TV, or reading. The patient should not wear contact lenses for several weeks following canthoplasty.

It takes approximately 2-4 weeks for a full recovery to take place after canthoplasty. Essentially, canthoplasty alters the eye’s shape and effectively enables the eye to be rejuvenated and refreshed to improve the patient's appearance. Usually, the patient will have a wider-eye appearance, with the eyes slanting slightly upwards. The procedure can result in an almond or cat-eye shape. It reduces the effect of eye bags and droopy eyes.