Strabismus surgery: what it does and what follows
- Topic
Squint surgery moves or tightens eye muscles to straighten the eyes. It aligns the eyes but does not cure amblyopia: glasses and patching still matter.
See it in 3D: Medial rectus · Lateral rectus · Superior oblique · Inferior oblique
What it is
Strabismus surgery changes the pull of the extraocular muscles. A recession moves a muscle's insertion back to weaken it; a resection or plication shortens a muscle to strengthen it; a transposition moves healthy muscles to take over from a paralysed one. Children are operated under general anaesthesia; adults may have adjustable sutures fine-tuned after surgery. Botulinum toxin injection into a muscle is an alternative in selected cases. Goals are alignment, binocular vision, relief of double vision and a normal head posture.
Key facts
- Correct the refractive error and treat amblyopia first; surgery straightens the eyes but does not restore vision in a lazy eye.
- Accommodative esotropia is treated with full hyperopic glasses, not surgery.
- Infantile esotropia is usually operated early in childhood to give the best chance of some binocular vision.
- Paralytic squints (sixth nerve palsy, thyroid eye disease) are operated only after the deviation has been stable for months.
- In adults, surgery relieves double vision and head turn and has real psychosocial benefit; it is not merely cosmetic.
- Some patients need more than one operation.
In clinical practice
- Traction on an eye muscle can trigger the oculocardiac reflex: sudden bradycardia or asystole during surgery, reversed by releasing traction and giving atropine.
- After surgery the eye is red and gritty for some weeks and brief double vision is common.
- Rare but serious: infection (orbital cellulitis, endophthalmitis after scleral perforation) and a slipped or lost muscle.
- A new squint or double vision in an adult needs a cause before surgery: nerve palsy, thyroid eye disease, myasthenia or a mass.
Next step / Initial management
- Child with a squint: refer to paediatric ophthalmology for cycloplegic refraction, amblyopia treatment and surgery if still needed.
- New squint or diplopia in an adult: look for the cause (neuroimaging when indicated, thyroid tests, myasthenia work-up) before surgery is discussed.
- After surgery: increasing pain, lid swelling, fever, discharge or a fall in vision needs same-day ophthalmology.
- Sudden loss of movement of the operated eye: urgent review (slipped or lost muscle).
- Keep glasses and patching going after surgery as prescribed.
Test yourself
Think of the answer, then tap the question to see it.
What is the difference between a muscle recession and a resection?
A recession moves the insertion back and weakens the muscle; a resection shortens it and strengthens it.
During squint surgery, the heart rate suddenly falls as the surgeon pulls on a muscle. What is happening and what is done?
The oculocardiac reflex; traction is released and atropine is given if needed.
What is the first-line treatment of accommodative esotropia?
Full correction of the hyperopia with glasses.
Why is surgery for a sixth nerve palsy delayed?
Many palsies recover, and surgery is planned only once the deviation is stable.
Connections
See it in 3D4
The structures of Durgical's 3D anatomy where it is found.
In Pharmacology1
Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.
Sources: Strabismus (StatPearls Publishing (NCBI Bookshelf), 2026); Esotropia (StatPearls Publishing (NCBI Bookshelf), 2023); Exotropia (StatPearls Publishing (NCBI Bookshelf), 2023).
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Representative model, for educational purposes only.