Strabismus
Strabismus, also known as crossed eyes, is a condition whereby the eyes fail to align correctly. One of the eyes can either turn inwards, outwards, upwards, or downwards as the other concentrates on a single point. It can occur all of the time or only on occasion.
Strabismus usually happens when the extraocular muscles, which regulate the eye and eyelid movement, aren't functioning together. Due to this, neither of the eyes can gaze at the same thing at the same time. This could also happen if the eyes are unable to coordinate properly as a result of a brain problem.
Because strabismus prevents binocular vision, it is difficult for the person to perceive depth perception.
Categories of Strabismus
Different types of strabismus exist. The cause or the manner in which the eye turns can both be used to describe them. The following defines strabismus in terms of eye positions:
- Hypertropia: This is where the eye turns upwards.
- Hypotropia: A condition in which the eye turns downward.
- Esotropia: This is when the eye turns inwards.
- Exotropia: Occurs when the eye turns outwards.
How Strabismus Alters Vision
The eyes usually focus at the same spot in normal vision. The brain integrates the eyes' two images into one 3-dimensional picture. This is how one determines the nearness or farness of something (depth perception).
If one of the eyes is misaligned, the brain receives two separate images. The brain of a young child learns to disregard the pictures of a misaligned eye. Instead, it only sees the picture from the better-viewing or straighter eye. Because of this, the child's depth perception is impaired.
Strabismus in adults can develop after childhood and is frequently associated with double vision. Since their brains have already learned to obtain images from the two eyes, they experience double vision. They perceive two images because their brains can't ignore the image from the rotated eye.
Signs and Symptoms of Strabismus
The majority of children who have strabismus don’t experience any eye problems or detect any alterations in their vision. The child’s teacher, family member, or medical provider usually observes that the eyes aren't straight.
Some children may experience double vision (viewing two objects when only one is present) or difficulty seeing things generally. Such issues can also have an impact on reading abilities as well as learning in class. Younger children who are not yet speaking might squint a lot, turn or slant their heads to see well.
Be sure to inform your doctor right away if your child exhibits any of such signs and symptoms of strabismus. If necessary, he or she may refer you to a specialized pediatric ophthalmologist.
Causes of Strabismus
Strabismus is a condition that some babies are born with. The pediatricians describe this as congenital strabismus. Often, there is no obvious cause. Nonetheless, the section of their nervous system regulating their eye muscles may be malfunctioning. They could also have a growth or an eye problem.
Strabismus could lead to double vision if it does not manifest till later in life. If the eyes of an adult cross suddenly and without any warning, they may be suffering from a catastrophic disease such as a stroke. If any of these things happen, consult your doctor right away.
Young children can inhibit vision in one of their weaker eyes, preventing double vision. Nevertheless, this could result in a "lazy eye," also referred to as amblyopia by your doctor. Peripheral vision (seeing to the side) and depth perception may be compromised. It might lead to headaches and eyestrain.
When your eyes cross as you become older, you might begin turning your head to evade double vision and see in particular directions.
Other medical conditions that can be linked to strabismus are;
- Uncorrected refractive errors
- Cerebral palsy
- Stroke
- Brain tumors
- Down syndrome
- Neurological problems
- Head injuries
- Grave’s disease
Strabismus Diagnosis
Any child over four months and looks likes he or she has strabismus needs to see a pediatric ophthalmologist for a full eye examination. During the examination, the provider will also spend some time looking at how the eyes concentrate and move.
The examination and other strabismus tests might as well involve the following;
- Patient's medical background: This helps identify the symptoms that the patient has and family history. It can also include general health issues, the drugs one is taking, or any other potential reason for symptoms.
- Visual acuity: This involves reading the letters on the eye chart or observing the visual behavior of the young child.
- Refraction: This entails examining the eyes using various corrective lenses to determine how they focus the light. When evaluating for glasses, the child does not need to be older to provide verbal input.
- Tests of alignment and concentrating
- After dilatation or widening of the pupils, an examination is performed to evaluate the overall health state of the internal structures of the eye.
Strabismus Treatment
There are various strabismus treatment options the eye doctor can recommend based on the type and underlying cause. He or she will also work with you to develop a suitable treatment plan:
- Eyeglasses
Sometimes, the baby gets esotropia because their eyes are over-focusing to balance their excessive degree of uncorrected farsightedness. In such cases, the treatment will involve correcting the child's eyesight condition completely.
The eyes won’t over-focus after wearing the proper eyeglass prescription. Besides, the eyes will straighten out right away. While correcting the visual impairment usually reduces the majority of the deviation, it might still happen when reading and assembling the eyes in. A bifocal lens can be prescribed in this circumstance to provide more power.
- Prism
A prism is a lens type that bends the light in one specific direction. The provider can recommend a prism to help move things into a certain position that enables users to merge pictures and avoid double vision. This is critical for some people who have strabismus and also experience a double vision. The converse power prism can be advised in some circumstances to improve the overall cosmetic look of strabismus.
- Botox
The doctor can directly inject Botulinum toxin in one of the eye-movement regulating muscles. The nerve impulse is briefly blocked while the muscle is paralyzed. When this muscle relaxes, the other eye muscles pick up the slack, allowing the eye to straighten. One of the early uses of Botox in medicine was for strabismus injections.
- Vision therapy
Vision therapy refers to a variety of procedures that can be used to fix strabismus. Alternatively, it can help teach the patient with strabismus how to recognize when an eye deviates and employ their eye muscles to reduce it.
Certain devices and computer software applications are sometimes employed to provide a behavioral response to the user in order to manage the deviation of the eye muscle. Particular eye muscle workouts may be used to strengthen the muscles around the eyes. Normally, vision therapy works well for exotropia and minor esotropia aberrations but not so well for high degrees of esotropia.
Vision treatment is typically considered contentious. Other ophthalmologists do not prescribe vision therapy unless the patient has convergence insufficiency. This is a condition in which the eyes have trouble functioning together when concentrating on a close object). You should thus consult your eye doctor to determine if vision therapy is suitable for you or your child.
- Surgery
Strabismus surgery is the most prevalent treatment option. It can help restore standard eyesight by improving the alignment of the eye.
Strabismus is basically a condition in which the muscles around the eyes are overly rigid or too weak. The doctor can thus suggest loosening, tightening, or moving some eye muscles in order for the eyes to align appropriately and function together. Surgical treatment for strabismus may require multiple surgeries to obtain the desired results.
In most cases, the operation is performed as an outpatient procedure in a hospital or surgical clinic, under general or local anesthetic. To get to the eye muscles, your ophthalmologist will create a small incision in the tissue around the eye. After that, the muscles are adjusted to assist the eyes in pointing in a similar direction. It's possible that you will have to do this in one or two eyes.
You can resume your normal day-to-day activities a few days after undergoing strabismus surgery.
- Eye muscle exercises
Your ophthalmologist can recommend learning certain eye muscle exercises to assist in focusing both eyes inward. If you have convergence deficiency, then these activities can be beneficial. Convergence deficiency is when the eyes don’t line up appropriately for close tasks such as computer work or reading.
Conclusion
Strabismus disorder occurs when the eyes do not line up correctly. Your eyes will gaze in different paths if you have an eye problem. This means that each of your eyes will be focused on a different thing.
Children are more likely to develop this illness, but it can also happen later in life. Strabismus in older children and adults can occur due to a variety of medical disorders, such as cerebral palsy or stroke. However, early diagnosis and treatment can help avoid long-term complications of the vision.