What is adult strabismus (squints)?
Strabismus (commonly known as squints) is a condition in which the eyeballs are not properly aligned and point in different directions. If it occurs in adults, it is then called adult strabismus. It affects approximately 4% of the adult population.
What causes adult strabismus?
Strabismus seen in adults can be the result of:
- Childhood strabismus
Strabismus that occurred in childhood that was not fully corrected or has since reoccurred,
- Medical problems
New-onset misalignment of the eyes can be due to certain medical conditions such as:
- Thyroid disease
- Myasthenia Gravis
- Brain tumours
- Head trauma
Surgery on or around the eye such as cataract or retina surgery can occasionally cause a misalignment of the eyes due todamage to the eye muscles during surgery.
What are the symptoms?
Adults with squints may experience:
- Eye fatigue, strain or headaches
- Double vision
- Overlapped or blurred images
- A pulling sensation around the eyes
- Reading difficulty
- Loss of depth perception
- Head posturing/tilting
- Inability to make direct eye contact with both eyes when looking at people, which can make social situations awkward. These symptoms may have a negative impact on employment and social opportunities.
How are squints in adults treated?
Surgical and non-surgical treatment options are available to treat adult strabismus.
Treatment choice is typically based on the severity of the strabismus.
Several methods are available, including:
- Glasses containing prisms
Eyeglasses with prisms can correct mild double vision associated with squints in adults. A prism is a clear, wedge-shaped lens that bends, or refracts, light rays. Prisms can help realign images together so that the eyes see only one image.
Botulinium toxin is used in certain cases of strabismus to temporarily paralyze a muscle to rebalance the eyes.
- Eye muscle surgery
This involves surgery on the muscles of the eye to rebalance the position of the eyes by either tightening or weakening the muscles.
Options should be discussed with your doctor so as to ascertain which ones are appropriate for you.
What should I expect with surgery?
Squint surgery is usually performed on an outpatient basis and can be performed under general or local anaesthesia. Patients may experience some pain or discomfort after surgery, but it is usually not severe and can be treated with over-the-counter pain medication such as paracetamol or ibuprofen.
Stronger medications for pain are sometimes needed and will be prescribed by your ophthalmologist or anesthetist. You can often return to your normal activities within a few days. More than one surgery may be needed to treat this condition depending on the severity of the case.
What are the risks of surgery?
A volume of research has shown adult strabismus surgery to be successful, long lasting, with relatively few risks.
Serious complications during and after adult strabismus surgery are uncommon. Nonetheless, the surgery has the following long-term risks:
- Postoperative acquired diplopia (double vision),
- Loss of binocular fusion
- Theneed for unplanned re-operation
- Perioperative risks related to deep scleral suture passes also may occur
- Lost or slipped muscles
- Anterior segment ischemia.
What are the benefits of surgery?
On the other hand, the benefits of strabismus surgery in adults include:
- Improved ocular alignment
- Reduction or elimination of diplopia
- Restored sensory binocular fusion
- Expansion of binocular visual field
- Improvement of an abnormal head position and
- Improved social skills and self-image
In a recent review on adult strabismus Professor Donahue stated, "Strabismus surgery in adults is not simply cosmetic.
It is reconstructive, and it has marked functional benefits, including the restoration of normal alignment and binocularity and the expansion of peripheral visual fields," The challenge is to get this information back to physicians and medical aids.