Disease Description (Causes and Symptoms)
- Definition: A condition in which the two eyes are not normally aligned, causing the line of sight of one or both eyes to deviate from the target (strabismus).
- Main pathophysiology: Caused by an imbalance among the extraocular muscles, nerves, and central nervous system that maintain binocular alignment. Various causes may act together, including sensory factors (reduced vision in one eye), refractive errors (accommodative esotropia due to high hyperopia), musculoskeletal or anatomical abnormalities (orbital fractures or muscle deformities), and neurological paralysis (cranial nerve III, IV, or VI palsy, myasthenia gravis, etc.). Genetic predisposition (approximately 30%) and ethnic differences (distribution of esotropia/exotropia) also have an influence.
- Main symptoms: Ocular misalignment (unilateral or bilateral), diplopia (in adults), amblyopia (in children), eye strain and photophobia, head tilt or abnormal head posture, headache and vomiting (in acute or severe cases), and diurnal variation in symptoms (intermittent strabismus).
- Frequency: Approximately 4% of the general population and 2–4% of children (approximately 3.6% reported among first-grade elementary school students in Korea).
Treatment Methods (Standard Treatment · Medications · Procedures/Surgery · Lifestyle Management and Precautions)
- Conservative treatment
- Refractive correction: Alignment often improves with glasses (such as correction of hyperopia), especially in accommodative esotropia. Accurate refractive testing is performed through cycloplegic examination.
- Glasses and prisms: Used to alleviate small-angle deviations or diplopia.
- Age-appropriate amblyopia treatment: Amblyopia is treated with occlusion (patching) therapy or medication (such as atropine to suppress the function of one eye).
- Orthoptic examination and eye exercises: Intended to improve intermittent strabismus or binocular visual function.
- Invasive treatment
- Botulinum toxin injection: Used for temporary correction in some paralytic and nonparalytic forms of strabismus.
- Extraocular muscle surgery: Corrects chronic or fixed deviations through muscle repositioning and weakening/strengthening procedures. The goals of surgery are to improve function (binocular vision) and cosmetic alignment.
- Treatment of underlying diseases: Treatment of underlying conditions such as thyroid eye disease, neuropathy, myasthenia gravis, and tumors (through medical, neurological, or surgical approaches).
- Situations requiring emergency care and additional testing: If sudden diplopia or strabismus develops in an adult, or if it is accompanied by ptosis, neurological symptoms, headache, or altered consciousness, immediate neuroimaging (brain/orbital CT/MRI) and urgent neurological and ophthalmological evaluation are necessary.
- Lifestyle management and self-care
- Children: Early detection and treatment are important (amblyopia can lead to permanent visual impairment). Regular vision examinations, adherence to wearing glasses, and strict compliance with patching instructions are important.
- Adults: Seek medical attention promptly if symptoms develop suddenly, and be cautious of safety accidents caused by diplopia when driving or operating machinery.
- Complications and precautions
- If untreated, children may develop amblyopia and permanent loss of stereopsis. Recurrence or overcorrection/undercorrection may occur after surgery. Infection, bleeding, or temporary changes in eye movement may occur after surgery or botulinum toxin injection.
- Prescribed instructions before and after surgery (medications and activity restrictions) and follow-up monitoring are necessary.
Checklist Before an Outpatient Visit (Including Example Questions)
- Items to prepare
- List of currently used medications, including eye drops
- Previous ophthalmic treatment and surgical records and prior test results (visual acuity charts, refractive examinations, fundus photographs, etc.)
- Family history (whether there is strabismus or amblyopia), birth history, and developmental history (for children)
- Records observing when symptoms began and how they have progressed (photos or videos are useful if available)
- Regularly worn glasses or contact lenses (bring them if applicable)
- Questions useful to ask during an outpatient visit (for personal records)
- When did the symptoms begin? Are they constant or intermittent?
- Which eye is drifting (or are both eyes affected)? Do you tilt your head or adopt an abnormal posture?
- Is there diplopia? Do the symptoms change when one eye is covered?
- Have you recently had a headache, vomiting, trauma, or neurological symptoms (such as difficulty speaking or sensory abnormalities)?
- Have you had any usual decrease in vision (such as difficulty reading, watching television, or viewing distant objects)?
- Special preparation for children: Prepare toys or snacks to attract the young child’s attention, and photographs (family or frontal facial photographs).
General Example Questions to Ask the Doctor
- What do you think is the cause of this condition? Are additional tests needed?
- What is the goal of treatment (vision recovery, eye alignment, resolution of diplopia, etc.)? What is the expected treatment duration?
- Is surgery necessary? What are the risks and expected benefits of surgery?
- What are the side effects of the medication (or glasses) currently being prescribed?
- What should I be careful about regarding self-care (lifestyle habits, activity restrictions, etc.)?
Condition-specific questions (examples)
- For children or concerns about amblyopia: "Does my child need patching (occlusion) treatment right away? What is the likelihood of success (prognosis)?"
- For adults with acute diplopia: "What tests should be performed, and by when, to determine whether these symptoms are caused by a neurological abnormality (such as a stroke or tumor)?"