Adult strabismus surgery, commonly known as adult squint surgery, is a specialized ophthalmic procedure aimed at realigning misaligned eyes. Strabismus occurs when the six extraocular muscles that control eye movement fail to work in a coordinated manner. This lack of alignment causes one or both eyes to turn inward (esotropia), outward (exotropia), upward (hypertropia), or downward (hypotropia).

The primary mechanism of surgery involves modifying the tension or attachment point of the extraocular muscles on the sclera (the white outer wall of the eyeball). By weakening an overactive muscle or strengthening an underactive one, ophthalmic surgeons restore physical alignment. The medical goal extends beyond cosmetic alignment; surgery aims to re-establish binocular single vision (the ability of both eyes to focus together on a single image), alleviate diplopia (double vision), reduce ocular fatigue, and improve spatial awareness.

According to guidelines from the American Academy of Ophthalmology (AAO 2019) and the Royal College of Ophthalmologists (RCOphth 2021), adult strabismus surgery is a restorative reconstructive procedure rather than a cosmetic one. Misalignment in adults often stems from childhood strabismus, thyroid eye disease, neurological disorders, vascular accidents, or orbital trauma.

Adult strabismus surgery is a meticulous microsurgical procedure performed under operating microscopes. The process follows several distinct clinical steps:

1. Anesthesia Administration: The patient receives general anesthesia or monitored local anesthesia with retrobulbar or topical block, ensuring complete comfort and immobilization of the eye.

2. Tissue Access: A small incision is made in the conjunctiva (the clear outer membrane) and Tenon's capsule to expose the target extraocular muscle without leaving visible external scars on the face or eyelids.

3. Muscle Isolation: The target muscle is isolated using specialized strabismus hooks. Absorbable synthetic sutures are secured tightly through the muscle tendon near its attachment site to the eye wall (sclera).

4. Execution of Surgical Technique:
- Recession (Weakening): The muscle is detached from the sclera and reattached further back on the globe at a precise, measured millimeter distance.
- Resection or Plication (Strengthening): A calculated segment of the muscle is removed (resection) or folded over itself (plication), shortening the muscle to increase pull force before reattaching it to its original insertion point.
- Adjustable Suture Technique: If selected, the muscle is tied with a temporary slip-knot, allowing fine adjustments hours after surgery while the patient is fully awake.

5. Closure and Adjustment: Incisions in the clear outer layer are closed using tiny, self-dissolving sutures. If an adjustable suture protocol is used, intraoperative positioning is re-evaluated, and final knot securing occurs in the recovery area.

6. Post-Operative Dressing: Protective eye pads or shields are applied, along with initial doses of anti-inflammatory and antibacterial eye drops.

Surgical realignment of the eyes in adults offers clear clinical advantages grounded in peer-reviewed ophthalmic research:

• Elimination or Reduction of Diplopia: Realignment brings visual axes together, eliminating double vision in central gaze and reading positions in up to 80% of treated adults (AAO PPP 2019).
• Restoration of Binocular Vision: Selected patients regain depth perception and binocular fusion, enhancing motor coordination and visual field awareness.
• Correction of Abnormal Head Posture: Patients who tilt or turn their heads to compensate for double vision experience relief from chronic neck strain and cervical spine stress.
• Expansion of Visual Field: Correcting inward-turning eyes (esotropia) expands the patient's peripheral visual field.
• Psychosocial and Functional Improvement: Alignment restores natural eye contact, improving interpersonal confidence, communication, and occupational performance (RCOphth 2021 guidelines).

Recovery following adult strabismus surgery progresses across clear clinical phases. Immediate discomfort, such as a scratchy feeling or foreign-body sensation, lasts for two to five days as conjunctival sutures heal.

During the first week, redness (subconjunctival hemorrhage) and mild swelling of the eyelid and clear eye tissue are expected. Topical antibiotic and steroid drops are applied three to four times daily to control inflammation and reduce infection risk. Most patients resume desk work and light activities within three to seven days.

By three to four weeks post-surgery, redness fades significantly, and physical activities—including swimming, heavy lifting, and contact sports—may be resumed following surgeon approval. Final ocular alignment and binocular visual stability are generally assessed at six to twelve weeks post-operatively.

Adult strabismus surgery treats several specific conditions and ocular alignment disorders:

• Esotropia: Inward turning of one or both eyes, including comitant, non-comitant, and accommodative forms.
• Exotropia: Outward drifting of the eyes, including intermittent and consecutive exotropia following prior pediatric procedures.
• Hypertropia and Hypotropia: Vertical eye misalignments caused by trochlear nerve palsy or inferior rectus restriction.
• Diplopia (Double Vision): Chronic horizontal, vertical, or torsional double vision resulting from misaligned visual axes.
• Paralytic Strabismus: Muscle weakness due to cranial nerve palsies (third, fourth, or sixth nerve palsies).
• Restrictive Strabismus: Physical restriction of muscle movement, often associated with thyroid eye disease (Graves' orbitopathy) or orbital fracture trapping.
• Torsional Strabismus: Abnormal rotational misalignment of the eye, often producing tilted double vision.

Pre-operative preparation ensures optimal surgical safety and accurate alignment planning:

1. Ophthalmic & Orthoptic Evaluation: Detailed measurement of strabismus angle using sensorimotor tests, prism cover tests in nine gaze positions, and evaluation of binocular vision potential.

2. Systemic Health Screening: Patients undergo complete medical evaluation, including blood pressure monitoring, electrocardiogram (ECG), and blood tests if general anesthesia is planned.

3. Medication Adjustment: Anticoagulants, antiplatelet agents, and non-steroidal anti-inflammatory drugs (NSAIDs) may be paused five to seven days before surgery under medical supervision to minimize surgical bleeding.

4. Fasting Protocols: For general anesthesia, strict fasting guidelines require no solid foods for six hours and no clear fluids for two hours before the procedure.

5. Hygiene Precautions: Patients are instructed to wash their face thoroughly on the morning of surgery and avoid wearing eye makeup, facial creams, or contact lenses.

Adult strabismus surgery is considered a safe procedure with low complication rates. Risks are classified by severity:

1. Mild and Common Risks:
- Foreign body sensation and redness: Expected for two to four weeks post-operatively.
- Mild eye pain or aching: Managed easily with over-the-counter analgesics.
- Transient double vision: Common as the brain adapts to new eye positioning; usually resolves within days or weeks.

2. Uncommon Risks:
- Overcorrection or Undercorrection: The eyes may turn too far inward/outward or retain residual misalignment, requiring prism glasses or secondary surgery.
- Granuloma or Suture Cysts: Benign inflammatory lumps at suture sites requiring steroid drops or minor excision.
- Scleral Perforation: Occurrences where thin eye walls are nicked by needle pass; managed immediately with prophylactic retinopexy or antibiotics.

3. Rare / Severe Complications:
- Endophthalmitis: Severe internal eye infection (less than 1 in 5,000 cases); requires urgent intravitreal antibiotic therapy.
- Lost or Slipped Muscle: Detachment of the muscle from its new scleral seat; requires prompt re-operation.
- Anteromedial Ischemia (Anterior Segment Ischemia): Disruption of blood supply due to operating on three or four rectus muscles simultaneously; minimized by staging procedures.

The clinical journey for adult strabismus surgery begins with a comprehensive orthoptic and ophthalmic evaluation. This assessment maps eye alignment, muscle function, and visual acuity. Patients undergo detailed measurement of their misalignment using prism tests across multiple gaze positions.

On the day of surgery, the patient arrives at an outpatient surgical center. The procedure takes between 40 and 90 minutes, depending on the number of muscles involved. Under general or local anesthesia, the surgeon accesses the extraocular muscles through small incisions in the conjunctiva (the clear membrane covering the white of the eye). Muscles are repositioned or shortened using delicate sutures.

Immediate post-operative recovery occurs in a recovery bay for two to four hours. If adjustable sutures are used, fine alignment tuning takes place later that day or the following morning under local anesthetic drops. Patients return home the same day. Full functional recovery typically spans two to four weeks, during which prescribed anti-inflammatory and antibiotic drops prevent infection and ease tissue swelling. Follow-up evaluations occur at one week, six weeks, and three months to confirm stability.