Strabismus Surgery

What is Strabismus Surgery?

Strabismus surgery or eye muscle surgery is a corrective treatment for eye misalignment (strabismus). Studies indicate that strabismus affects about 4% of the U.S. population.¹ 

Due to muscle dysfunction, people with strabismus find it difficult to control their eyes. One eye may look directly at an object, while the other may look in a different direction.

Strabismus surgery entails loosening or tightening the eye muscles to restore proper alignment and muscle movement.³

Strabismus Surgery Methods

Depending on your condition, your surgeon may use one of these strabismus surgery methods:

Muscle Recession 

This procedure addresses tight eye muscles that cause the eye to pull in one direction. It involves detaching the muscle and reattaching it farther back in the eye. This weakens the muscles, resulting in improved alignment.

Muscle Resection

This procedure addresses weak eye muscles. It involves detaching the eye muscle from its original position and shortening it before reattaching it. This strengthens the muscles and enables better alignment.

Adjustable Suture 

This procedure happens during muscle recession or resection. Adjustable sutures enable the surgeon to easily change the muscle attachment position if your eyes don’t align well after the initial surgery.⁶

What Eye Issues Can Strabismus Surgery Treat?

Strabismus surgery treats several types of eye issues. These issues include:

• Esotropia (crossed eyes). When the eye turns inwards, towards the nose
• Exotropia (walleye). When the eye turns outwards, away from the nose
• Hypertropia. When one eye turns upward
• Hypotropia. When one eye turns downward
• Cyclotropia (rotational strabismus). When one eye rotates outwards or inwards around its visual axis

If left untreated, strabismus may reduce vision in one eye (amblyopia or lazy eye). It may also result in low self-esteem due to appearance issues.

Early strabismus diagnosis can prevent serious conditions, such as brain tumors. A brain tumor can interfere with the afferent and efferent visual pathways, causing misalignment.⁴

Ideal Candidates for Strabismus Surgery

Strabismus surgery is ideal for both children and adults with eye misalignment issues. If strabismus is caught early enough in children, it can restore vision and depth perception. It can also prevent vision loss.⁷

You may qualify for strabismus surgery if you:

• Have crossed eyes
• Experience blurry or double vision
• Experience changes in depth perception
• Have difficulty reading
• Squint your eyes
• Tilt your head to see clearly

You will not qualify for strabismus surgery if you:

• Have muscle or nerve disorders such as muscular dystrophy, myasthenia gravis, or spastic cerebral palsy
• Have unrealistic expectations (e.g., if you expect not to wear your eyeglasses after surgery)
• Have underlying health conditions that can interfere with surgery or healing
• Take certain medications that can cause excess bleeding during surgery, such as blood thinners

Alternative Treatments

If you don’t qualify for surgery, your doctor may recommend alternative options such as:

• Eyeglasses or contacts. For people with refractive errors
• Patching (occlusion). Treats amblyopia (lazy eye) alongside strabismus
• Prism lenses. Special lenses that regulate the amount of light entering the eyes
• Botulinum toxin injection. The botulinum toxin is known to weaken overactive muscles for extended periods, making it effective for treating early overcorrection after strabismus surgery
• Monocular occlusion or fogging. Treats intractable diplopia or candidates who don’t qualify for surgery
• Eye exercises. Useful in mild strabismus cases

Strabismus Surgery Procedure: What to Expect

Below is what to expect before, during, and after strabismus surgery:

Before Surgery

Before surgery, your eye doctor will conduct tests to determine your general health, eye health, and the best type of surgery to perform. If you qualify for the procedure, they will schedule you for surgery.

Your doctor might instruct you to stop using certain medications, such as blood thinners and nonsteroidal anti-inflammatory products (NSAIDs), at least one week before surgery. 

Ask a friend or family member to drive you to your surgery, as your driving ability may be affected for several days. You should also avoid eating or drinking several hours before surgery.⁵

During Surgery

Strabismus surgery is an outpatient procedure performed under general or local anesthesia, depending on the extent of the condition. 

After sedation, the surgeon will open your eyes using an eyelid holder. Then, they will make an incision in the conjunctiva to access and isolate the eye muscles. The conjunctiva is the eye’s mucous membrane that covers the sclera (white of the eye).

The surgeon will either perform a muscle recession, a muscle resection procedure, or an adjustable suture procedure.

When the muscle is reattached to the eyewall, the surgeon uses a permanent knot instead of an adjustable suture. They may also use an adjustable suture technique that uses either a temporary bow or a slip knot.  

The surgeon can make adjustments following surgery. They typically perform these adjustments under local anesthesia. The adjustable suture procedure is typically performed on adults.

After Surgery (Recovery)

After strabismus surgery, your sclera (white of the eye) may appear red. A return to normal can take weeks to months after surgery. You’ll likely experience some pain and discomfort during early recovery, which should clear up with time.

It’s also advisable to see your doctor for follow-up care. During follow-up visits, your surgeon will evaluate the healing process and make any adjustments if necessary.

If your surgeon uses an adjustable suture, they might provide a protective patch to wear. They might also prescribe medications such as antibiotic eye drops or ointments to ease discomfort and prevent infections.

Most people can resume normal activities after about 2 weeks. Always consult your eye doctor before resuming strenuous or risky activities such as contact sports or swimming.

Risks of Strabismus Surgery

Common side effects of strabismus surgery include:

• Sore, gritty, or red eyes
• Double vision (lasts a few days to a few weeks)
• Eyestrain
• Headache
• Blurry vision 
• Swollen eyelids

Some possible complications of strabismus eye surgery include:

• Poor eye alignment
• Vision changes
• Diplopia (double vision)
• Scarring
• Damaged sclera
• Post-operative infections
• Allergic reaction
• Lost muscle⁸
• Subconjunctival abscess

You can minimize complications if your doctor thoroughly examines you before the surgery. You should also adhere to post-operative care practices to further reduce risks. 

Call your doctor if you notice the following after surgery:

• Obvious signs of bleeding
• Fluctuating vision
• Intense eye pain
• Unbearable light sensitivity
• Signs of infections, such as pus

Strabismus Surgery Outlook and Success Rates

In most cases, the procedure is safe and effective.

One study shows that horizontal strabismus surgery has a 72.67% success rate.¹¹ In addition, there is a low risk of serious complications. 

Note: Strabismus may not correct vision. In many cases, success is defined by an improvement in appearance. However, most adults realize some improvement in binocular function after eye muscle surgery.¹⁰ Some people may regain stereopsis (depth perception).

People who do not have correct alignment after the first strabismus surgery might benefit from a second surgery. This usually happens a few months to a few years after the outcomes from the first surgery have stabilized.

Summary

Strabismus surgery corrects eye misalignment (strabismus). This procedure loosens or tightens the eye muscles to restore normal alignment and muscle movement. The surgery is performed in an outpatient setting and has a high success rate.