What is Strabismus Surgery?

Strabismus is typically a childhood eye condition with infantile beginnings or cases linked with extreme hyperopia and accommodation difficulties. It, however, affects individuals of all ages. Childhood-onset strabismus is one of the most frequent eye diseases in children and teenagers, with a prevalence between 2% and 6%. The likelihood of reduced stereopsis, vision loss, difficulty with daily tasks, and a lower quality of life increases in children who develop strabismus. There is substantial empirical and anecdotal evidence that adults with strabismus face a diminished quality of life.

What is Strabismus Surgery?

Misalignment correction for cosmetic reasons and, if possible, restoration of BSV are the most common reasons for undergoing extraocular muscle surgery. Surgery can also be used to increase or centre a BSV field and fix an abnormal head posture. One of the first steps in treating strabismus in children is to correct any significant refractive error or begin amblyopia treatment. Surgery to correct residual deviation is possible if both eyes have reached their optimum visual acuity.

Amblyopia, also known as "lazy eye," is a condition in which the vision in one eye is reduced because the eye and brain are not properly aligned or are not working together properly.

Indications for the Surgery:

We can divide the indications into two subcategories:

1. Cosmetic

2. Restorative

The justification for surgery and the goal of the procedure should be determined after careful consideration of the patient's specific circumstances. The strabismus surgeon must question, "Why are we going to operate?" to determine the therapy goals before surgery. Strabismus in adults can be surgically corrected to restore binocular vision, reduce diplopia, or eradicate ocular torticollis. It can widen the binocular visual field in esotropia patients, improve psychosocial functioning, and increase the likelihood of economic and occupational success.

Techniques of the Strabismus Surgery

The well-known resection and recession procedures were first performed near the end of the 1800s. The development of more advanced strategies parallels the introduction of new technologies. Strabismus surgery can be broadly classified into four types.

1. Muscle Strengthening Procedures:

• Resection of the rectus muscle

• Plication or tucking of the extraocular muscle

2. Muscle Weakening Procedures:

• Recession: It can be done for all the muscles except for superior oblique

• Myectomy or disinsertion

• Posterior Fixation Suture Procedure also known as Faden Surgery

• Hang Back Recession: Less chance of scleral perforation. Indicated in high myope patients with a thin sclera.

3. Transposition Surgeries: They are done in patients with partial third cranial nerve palsies, six cranial nerve palsy, lost MR from strabismus surgery and in Duane Syndrome.

• Full Tendon Transposition

• Augmented Full Tendon Transposition (Foster Modification)

• Split Tendon Transposition

• Hummelsheim Procedure

4. Botulinum Toxin Chemodenervation

Possible Complications of the Surgery:

The complications can be divided into intraoperative, early, and late postoperative complications:

1. Intraoperative

• Malignant hyperthermia

• Lost muscle: Medial Rectus is the most common muscle loss.

• Slipped muscle: It occurs within the muscle capsule and can be prevented by adequate suture placement

• Oculo-cardiac reflex

• Haemorrhage

2. Early postoperative

• Under- or over-correction

• Late misalignment: It can be caused by scarring, poor fusion, poor vision, altered accommodation

• Mild conjunctivitis

• Pre-septal cellulitis/orbital cellulitis

• Endophthalmitis

3. Late postoperative

• Diplopia:

• Droopy lids (ptosis)

• Dellen and conjunctival cysts

4. Botulinum Toxin-related Complications:

•Scleral perforation

• Retrobulbar haemorrhage

• Temporary ptosis (common)

• Vertical squints

• Diplopia

• Mydriasis (Mydriasis is a condition characterized by the dilation of the pupils, or the black circles in the center of the eyes.)

How effective is strabismus surgery?

Surgery to correct strabismus, particularly in adults, is highly successful, extremely cost-efficient, and carries a shallow risk of serious complications. Adults with strabismus corrected have reported improvements in their visual acuity, mood, social interactions, and even employment prospects. The importance of the outcome to patients cannot be overstated.

It is a common misconception among those suffering from strabismus that treatment is difficult, hazardous, or ineffective. Eye practitioners who aren't aware of the statistics around the successful treatment of adult strabismus often contribute to spreading these falsehoods. If an adult patient has strabismus, referral to an ophthalmologist who specializes in treating adult strabismus should be considered.

Author: Dr. Muhammad Saad

Resident Ophthalmologist-Pediatric and Strabismus Department

Al-Shifa Trust Eye Hospital

Rawalpindi, Pakistan