Summary about Disease
Non-paralytic strabismus, also known as concomitant strabismus, is a type of eye misalignment (strabismus or "crossed eyes") where the angle of deviation between the eyes remains relatively constant in all directions of gaze. This means the misalignment is consistent regardless of which direction the eyes are looking. Unlike paralytic strabismus (which involves weakness or paralysis of one or more eye muscles), non-paralytic strabismus is usually due to problems with eye muscle control or focusing, not a specific muscle palsy. It often develops in childhood and can affect depth perception and vision if left untreated.
Symptoms
Visible eye misalignment (one eye turns in, out, up, or down)
Double vision (diplopia) – more common in adults, children often suppress the image from one eye
Head tilting or turning to compensate for the misalignment
Reduced depth perception
Eye strain or headaches
Decreased vision in one eye (amblyopia or "lazy eye") may develop in children if the brain suppresses the image from the misaligned eye.
Causes
The exact causes of non-paralytic strabismus are not always fully understood, but several factors can contribute:
Refractive errors: Uncorrected farsightedness (hyperopia) is a common cause, as the eye over-focuses to see clearly, which can lead to inward turning (esotropia).
Muscle imbalances: Subtle differences in the strength or positioning of the eye muscles can contribute.
Brain control issues: Problems with the brain's control of eye movements and coordination.
Genetics: A family history of strabismus increases the risk.
Other medical conditions: In some cases, underlying conditions like cerebral palsy, Down syndrome, or premature birth can be associated with strabismus.
Medicine Used
While medication isn't a primary treatment for correcting the eye misalignment itself in non-paralytic strabismus, eye drops are often used:
Atropine eye drops: These are used to blur the vision in the stronger eye to force the weaker eye to work harder, treating amblyopia.
Miotic eye drops (e.g., echothiophate): These drops were previously used to attempt to reduce the angle of the eye turn, but they are rarely used today due to side effects and limited effectiveness.
Note: Eyeglasses with prism correction are often prescribed to help align the eyes and reduce double vision. Surgery to correct eye muscle alignment is also a common treatment.
Is Communicable
No, non-paralytic strabismus is not a communicable disease. It cannot be spread from person to person.
Precautions
There are no specific precautions to prevent non-paralytic strabismus, as it is often related to underlying factors or genetic predisposition. Early detection and treatment are crucial for preventing vision loss. Regular eye exams for children are essential, particularly if there is a family history of strabismus or amblyopia.
How long does an outbreak last?
Non-paralytic strabismus is not an infectious disease that causes outbreaks. The condition is present chronically and requires ongoing management. The duration of treatment depends on the severity of the strabismus, the age of the individual when treatment starts, and the response to treatment.
How is it diagnosed?
Diagnosis typically involves a comprehensive eye exam by an ophthalmologist or optometrist, including:
Visual acuity testing: Measures how well each eye sees.
Refraction: Determines the need for glasses.
Eye alignment assessment: Various tests are used to measure the degree of eye misalignment (e.g., cover test, Hirschberg test).
Eye movement evaluation: Assesses the range of motion and coordination of the eye muscles.
Stereopsis testing: Measures depth perception.
Pupil examination: Assesses pupil function.
Slit-lamp examination: Examines the structures of the eye.
Dilated fundus examination: Examines the retina and optic nerve.
Timeline of Symptoms
Infancy/Early Childhood: Eye misalignment may be noticed by parents or caregivers. Infants may normally have intermittent crossing of the eyes.
Childhood: Reduced depth perception, Head tilting, or turning to compensate, Eye strain or headaches may be reported. Amblyopia (lazy eye) may develop in children if the brain suppresses the image from the misaligned eye.
Adulthood (if untreated): Uncorrected strabismus can lead to persistent double vision, eye strain, reduced depth perception, and cosmetic concerns. Some adults may develop suppression or abnormal head posture to compensate.
Important Considerations
Early detection and treatment are crucial, especially in children, to prevent or treat amblyopia.
Treatment options vary depending on the type and severity of strabismus and may include eyeglasses, prism correction, vision therapy, and/or surgery.
Compliance with prescribed treatment (e.g., wearing glasses, patching) is essential for successful outcomes.
Long-term follow-up is often necessary to monitor eye alignment and vision.
Adults with strabismus can also benefit from treatment to improve vision, reduce double vision, and improve cosmetic appearance.
Amblyopia treatment is most effective when started early in life. The window of opportunity for treating amblyopia decreases with age.