Eye Muscle Surgery

The eye muscle surgery process begins with a thorough evaluation of the eye condition to identify the muscles responsible for the misalignment and the degree of adjustment needed. The surgery is usually performed under general anesthesia for children and most adults, or under local anesthesia with sedation for some adults. In some cases, adjustable sutures may be used to fine-tune the alignment immediately after the surgery. The surgeon makes a small incision in the conjunctiva, the thin membrane covering the white part of the eye (sclera), to access the eye muscles underneath. There are two main procedures: weakening a muscle (Recession) by detaching it from its original insertion point on the eye and reattaching it further back, which reduces its pull; or strengthening a muscle (Resection) by removing a small section of the muscle and reattaching it to its original position, making it shorter and stronger. The surgery may involve working on one or more muscles in one or both eyes. The conjunctival incision is closed with fine, dissolvable stitches. The surgery typically takes between 30 minutes to two hours depending on the complexity and the number of muscles being adjusted.

Eye muscle surgery itself does not cause symptoms; rather, it is a treatment for strabismus and its associated conditions. The symptoms treated by this procedure and their underlying causes include: The main symptoms of strabismus that necessitate surgical intervention if other treatments are unsuccessful:

• Obvious misalignment of the eyes: One eye appears to turn (in, out, up, or down) compared to the other.
• Double vision (Diplopia): Seeing two images of a single object, which is more common in cases of late-onset strabismus or uncorrected strabismus in adults.
• Difficulty with depth perception: Due to the inability of the eyes to work together effectively.
• Eye strain and headaches: Especially when reading or focusing for extended periods.
• Tilting the head or covering one eye: In an attempt to achieve clear vision or avoid double vision.
• Amblyopia (Lazy Eye): In young children, the brain may suppress the visual signal from the misaligned eye to avoid double vision, leading to reduced vision in that eye if not treated early.

Causes that lead to strabismus and necessitate muscle surgery if required:

• Imbalance in eye muscles: Lack of coordination in the strength or function of the six muscles that move each eye, which is the most common cause.
• Neurological problems: Damage to the nerves that control eye muscles due to conditions such as cerebral palsy, stroke, brain tumors, or head injuries.
• Significant uncorrected refractive errors: Especially high farsightedness in children, which can cause inward turning of the eye (Esotropia) due to excessive effort on the eye muscles to focus.
• Certain medical conditions affecting the eye: Such as congenital cataracts or retinal diseases affecting vision in one eye, disrupting the brain's ability to maintain eye alignment.
• Congenital or acquired strabismus: Strabismus sometimes appears at birth or within the first few months of life (congenital), or it may develop later in childhood or adulthood due to the reasons mentioned above (acquired).
• Genetic factors: There might be a family history of strabismus.

Diagnosis of strabismus and determining the need for eye muscle surgery are based on a comprehensive eye examination and precise evaluation of eye muscle function. Diagnostic steps include:

• Complete medical history: Including family history of eye conditions and strabismus.
• Visual acuity testing: To determine the extent of vision impairment in each eye.
• Comprehensive eye examination: Includes examining the front and back parts of the eye to ensure the absence of other diseases that could cause strabismus or affect treatment.
• Evaluation of eye alignment and movement: Using various tests such as the Cover Test and Prism Adaptation Test to measure the angle of deviation in different gaze positions.
• Evaluation of binocular vision: Including the ability to see in 3D.

The primary treatment for strabismus that does not respond to glasses or eye exercises is eye muscle surgery. Treatment stages:

• Pre-operative evaluation: The muscles requiring adjustment and the amount of adjustment are determined based on precise measurements of the strabismus. The goals of surgery, potential risks and benefits, type of anesthesia used, and expected recovery period are discussed with the patient or their parents.
• Surgery: Performed in a sterile operating room under appropriate anesthesia. The surgeon makes the necessary adjustments to the eye muscles (weakening or strengthening) through small incisions in the conjunctiva.
• Post-operative recovery: A patch or shield is placed over the eye for a few hours. The patient may experience some pain, discomfort, redness, and swelling in the eye for several days or weeks. Eye drops (antibiotics and anti-inflammatories) are prescribed to aid healing.
• Follow-up appointments: It is important to attend follow-up appointments with the ophthalmologist to monitor the healing process and evaluate eye alignment after surgery. In some adult cases, minor adjustments to the sutures may be made on the first day after surgery using adjustable sutures.
• Surgical outcomes: Surgery is often effective in improving eye alignment, but in some cases, additional surgery may be needed to achieve optimal results, especially in complex strabismus or cases where deviations recur over time. Some patients may need to continue wearing glasses after surgery to correct underlying refractive errors.