Can Uneven Eyes Caused by Canthopexy Be Corrected?

Dear Overcorrected
I apologize to your friend on behalf of the surgeon who did this. I don't know that surgeon. However, I can assure you that if he/she had any idea that this would be the results eyelid surgery would never had been recommended. Canthopexy is not the answer. Canthopexy is a simple procedure that uses a stitch to tighten the lateral canthal angle. It is generally performed by eyelid surgeons who are not trained to perform an actual lateral cathoplasty.
The canthoplasty actually involved cutting the lateral canthal angle. The lower and upper limbs of the eyelid can then be separately tighten and the entire position of the angle can be changed. General plastic surgeons, and facial plastic surgeons get no training in this procedure. However, it is a common maneuver for oculoplastic surgeons.
In looking carefully at your friend's eyelids, there are a number of concerns. The right upper eyelid is ptotic or droopy. This contributes to the right eye looking small. The fat in the upper eyelids is over resected but this is a greater problem on the right. There is eyebrow ptosis with a flatness to the brow as if the forehead has been injected with too much BOTOX.
There is upper eyelid lash ptosis with the eyelashes pointing down. This problem is worse on the right side. The palpebral fissure, space defined by the eyelids around the eye has been made vertically shorter on the right but horizontally shorter on both sides also contributing to the eyes looking small. Normally when one looks at the eyes, the actually edge of the lower eyelid behind the eyelashes should not be visible. Here it is rolled out due to the incision below the eyelashes which is effectively focally rotating the lower eyelid margin out.
As this picture is only 4 weeks from surgery, it is likely that a number of this issues may get a little worse over the next few weeks and then gradually improve. However, it is likely that there will be a number of residual concerns that may need surgery to improve. This should not be undertaken for 6 to 12 months.
I think it is worth your while to consult with an oculoplastic surgeon who specializes in fixing post surgical issues just so you have these relationship and an opinion independent of your current surgeon.

Yes, and no.
Eyelid conditions may be treated with reconstructive plastic surgery, but surgery cannot be reversed to put the eyelids exactly where they were prior to cosmetic surgery.
You have complicated eyelid issues based on the information presented, and only after a comprehensive examination can one be able to determine (1) all the issues, and (2) potential treatment options.
That being said, you are still relatively early after your lower eyelid surgery. The slight slightness of the lower eyelids may still relax, and help resolve the slight slant appearance.
The lower eyelids appear to be in potentially in suboptimal position. Canthopexy, or alternative lateral (side) eyelid procedures, may pull the eyelid upward and closer to the eyeball itself. There are many specific procedures, which differ depending on the exact cause of the eyelid malposition. Grafting with skin or mucosa may be necessary.
Lastly, the upper eyelids appear uneven on the photograph. Did you have upper eyelid surgery or brow lift surgery too? Speak with your eyelid plastic surgeon, and determine what should be the next step. Best of luck.

It is best to wait at least 6 months for things to settle and heal completely.  The eyelid position may change up to 6 months or longer.  If they are still problematic (either functionally or cosmetically) after this period, then they can be evaluated for possible surgery.

It is possible to reverse the canthopexy procedure through a revision canthoplasty and/or canthopexy. They can be taken down or removed. The eyelids can be made more symmetrical. It is important to wait at least six months prior to undergoing any revision surgery of this nature.

Dear Overcorrected,
Personally, I do NOT think the canthopexies are the major reason for your friend's appearance. Canthopexies are usually put in to support contact of the lower lid with the eye balls when some inflammatory drag by the lower lids is anticipated. But if GREATER support is needed, canthoplasties may be called for.
In looking at her from the top down, she has:
1. Very asymmetrical brows with arch collapse, Right worse than left. Appears to be a "bad Botox" result of the kind one sees done in salons.
One wonders IF the Botox mediated brow sagging led to the performance of bilateral upper lid blepharoplasties.
2. Uneven position of the upper lids with apparent retraction of the Left upper lid and OVER resection of fat from the upper lids (especially right central compartment) creating an aging, skeletonized hollowness
3. Rounding of the outer corner of the left eye with much more white showing leading to some inflammation. This side appears to have been detached or have a failed tightening procedure.
Personally, I would stop all Botox treatments. Keep the lower left lid outer area higher with tape at night and wait 6 months or so before changing anything surgically. The left upper lid may come done a lot and the left corner may come up some as well.
Take some pictures in the spring and compare to this one to see the changes. At that time, you will have a real idea what the permanent look is and would, if needed, see several plastic surgeons who specialize in eye surgery to learn from each what your friend's options may be.
Good Luck.