Surgical treatment of strabismus

• Strabismus is a misalignment of eyes.
• There a number of “laymen” terms: Lazy eye, crossed eye, wandering eye…
• Strabismus is a general terms that encompasses many forms of Ocular Misalignment.

Types of Strabismus:

• Eso-tropia: Eyes turning in
• Exo-tropia: Eyes turning out
• Vertical deviation: Hyper-tropia / Hypo -tropia

• Sometimes strabismus presents as a compensating head tilt. Surgical correction often treats the head tilt. This is true for both children and adults.
• Sometimes a perceived strabismus is Pseudo-Strabismus
• Strabismus can have patterns – such as “A” or “V”
• These “patterns” are a sign of early (infantile) interruption of binocular vision development.
• The deviation & pattern can be surgically corrected.

• Each eye views objects at slightly different angle, from which the brain creates a 3-dimensional image. This requires perfect alignment of the eyes.
• In childhood, the brain has the capacity to ignore the image from a misaligned eye, avoiding double vision.  But the cost is a “lazy eye” – which if not treated in timely fashion, will result in poor vision for life.
• When misalignment develops in adulthood, the brain is not able to suppress the double vision.
• The difference between two individuals who have misaligned eyes, one with double vision & the other without double vision, is the age at which the problem began.

• Most commonly it due to the deterioration or recurrence of a childhood problem.
• Other causes include: stroke, auto immune disorders, and orbital injuries.

• No. In general it is never too late for surgical correction.

• Re-operation is possible, & generally successful.

• The most common causes of strabismus in adults are:
  Untreated childhood strabismus
  Deterioration of a childhood problem
  Recurrence of a treated childhood problem.
• All Pediatric Ophthalmologists are initially trained as an Adult Ophthalmologist, and subsequently specialize in the combined field of Pediatric Ophthalmology & Strabismus.
• Strabismus is more common in children than adults.  As such Pediatric ophthalmologists have the most expertise in dealing with ocular misalignment in all age groups

• Numerous studies have confirmed that strabismus is not simply a cosmetic problem.
• When ocular deviation is pronounced it becomes a communication disorder – affecting relationships, job performance, and psychological health.
• In some, surgery restores binocular function and expands the visual field back to normal.
• When there is constant double vision, it is often so disabling that patients have to resort wearing a patch on one eye to function.

• Botox® (Botulinum Toxin) was initially developed and tested by Alan Scott MD for the treatment of Strabismus.
• It’s use as an agent to smooth wrinkles came a decade later.
• The effect wears off in time, and outcomes can at times be unpredictable: as such its use is limited.
• In selected individuals it is quite effective, but in general is not a replacement for surgery.

• Surgery may not fully address the deviation, and there may be long term shifts, producing over-corrections or under-corrections.
• Studies suggest up to 20% of childhood cases may require a future re-operation.

• An Adjustable suture is a special type of slip knot, used at the time of surgery, to hold an eye muscle in place.
• This technique allows the surgeon to adjust the eye position in the first 24 hours after an operation.
• Thus over or under-corrections in the immediate postoperative period can be addressed without requiring a re-operation.

• Surgery is generally done as an Outpatient (No hospital stay)
• There is no Skin incision.
• Access to the eye muscles is achieved by making a small opening (~1cm) and stretching the conjunctiva to expose and operate on the eye muscle(s)

• Surgery is generally performed under anesthesia.
• Once the eye muscle is exposed, a hook is placed beneath the muscle insertion and a suture is passed close to the insertion of the muscle.
• The eye muscle is disinserted and moved to a new position.