“If this blog helped you out, don’t keep it to yourself—share the link on your socials!” 👍 “Like what you read? Spread the love and share this blog on your social media.” 👍 “Found this useful? Hit share and let your friends know too!” 👍 “If you enjoyed this post, please share the URL with your friends online.” 👍 “Sharing is caring—drop this link on your social media if it helped you.”

Saturday, August 23, 2025

Double vision


Introduction

Diplopia (double vision) is the perception of two images of a single object. It may be monocular (present in one eye only) or binocular (present only when both eyes are open, disappearing if one eye is closed).

  • Monocular diplopia is usually ocular in origin (cornea, lens, retina).

  • Binocular diplopia usually indicates a problem with ocular alignment, commonly due to cranial nerve palsy, muscle disease, or central nervous system pathology.

Diplopia can severely impair daily functioning and may signal life-threatening conditions such as stroke, aneurysm, or intracranial mass.

Classification of Double Vision

  1. Monocular Diplopia

    • Persists when the unaffected eye is covered.

    • Often optical in nature (refractive error, corneal/lens abnormality).

  2. Binocular Diplopia

    • Disappears when either eye is closed.

    • Due to ocular misalignment from neuromuscular or central causes.

Causes of Double Vision

A. Monocular Causes (Ocular/Optical)

  • Refractive errors (astigmatism, keratoconus).

  • Corneal irregularities (scar, ectasia).

  • Lens abnormalities (cataract, dislocation).

  • Retinal pathology (macular edema, epiretinal membrane).

  • Dry eye syndrome (irregular tear film).

B. Binocular Causes (Ocular Misalignment)

1. Cranial Nerve Palsies

  • CN III (Oculomotor nerve): Ptosis, eye deviated down and out, dilated pupil if compressive.

  • CN IV (Trochlear nerve): Vertical diplopia, worse on looking down and in (reading, stairs).

  • CN VI (Abducens nerve): Horizontal diplopia, worse on lateral gaze.

  • Causes: diabetes, hypertension (ischemic), stroke, trauma, tumors, aneurysm.

2. Neuromuscular Junction Disorders

  • Myasthenia gravis: Fluctuating diplopia, ptosis, worsens with fatigue, improves with rest.

3. Muscle Disorders

  • Thyroid eye disease (Graves’ orbitopathy): Restriction of extraocular muscles.

  • Orbital myositis, trauma, entrapment (orbital fracture).

4. CNS Disorders

  • Stroke, multiple sclerosis, demyelinating disease.

  • Intracranial tumor or aneurysm.

  • Increased intracranial pressure.

5. Strabismus

  • Congenital or acquired misalignment of eyes.

Clinical Features

  • History: Sudden vs gradual onset, monocular vs binocular, associated neurological symptoms (headache, limb weakness, dysarthria).

  • Symptoms: Double images (horizontal, vertical, oblique), worsened with specific gaze directions.

  • Associated signs:

    • Ptosis (CN III palsy, myasthenia).

    • Proptosis, lid retraction (thyroid eye disease).

    • Facial numbness (orbital mass compressing nerves).

    • Neurological deficits (stroke).

Diagnostic Approach

1. Differentiate Monocular vs Binocular Diplopia

  • Ask patient to cover one eye.

    • If persists: monocular (optical cause).

    • If disappears: binocular (neurological/neuromuscular).

2. Examination

  • Visual acuity, refraction.

  • Ocular motility testing (H-pattern gaze).

  • Pupillary reactions.

  • Cover test for strabismus.

  • Eyelid examination (ptosis, retraction).

  • Proptosis (thyroid disease, orbital tumor).

3. Investigations

  • Blood tests: Glucose, HbA1c (diabetic neuropathy), thyroid function (Graves’).

  • Antibodies: Anti-AChR antibodies for myasthenia gravis.

  • Imaging:

    • CT/MRI brain/orbits (tumor, stroke, aneurysm).

    • Orbital CT (fracture, thyroid orbitopathy).

  • Electromyography (EMG): Myasthenia gravis.

Management and Treatment

Treatment depends on cause and urgency.

A. General Measures

  • Treat underlying cause.

  • Temporary prism glasses for diplopia correction.

  • Eye patching to eliminate double image.

  • Sunglasses to reduce glare.

B. Specific Treatments

1. Monocular Diplopia

  • Correct refractive error with glasses/contact lenses.

  • Manage dry eye with lubricating drops:

    • Carboxymethylcellulose 0.5% drops: 1–2 drops every 4 hours as needed.

  • Treat cataracts surgically (phacoemulsification + intraocular lens).

  • Corneal disease: artificial tears, keratoplasty if severe.

2. Cranial Nerve Palsies

  • Ischemic palsy (diabetes, hypertension): Often resolves spontaneously within 3–6 months. Optimize risk factors (control glucose, BP, cholesterol).

  • Compressing aneurysm/tumor: Urgent neurosurgical/vascular intervention.

  • Symptomatic relief:

    • Patching or prisms.

    • Strabismus surgery if persistent >6–12 months.

3. Myasthenia Gravis

  • Pyridostigmine: 30–60 mg orally every 4–6 hours.

  • Corticosteroids: Prednisone 10–60 mg orally daily, titrate.

  • Immunosuppressants: Azathioprine 1–3 mg/kg orally daily.

  • Severe cases: IV immunoglobulin or plasma exchange.

4. Thyroid Eye Disease

  • Control thyroid function.

  • Corticosteroids for acute inflammation: Prednisone 40–80 mg orally daily, taper.

  • Radiotherapy or orbital decompression in severe cases.

  • Prisms or strabismus surgery for persistent diplopia.

5. Orbital Trauma/Entrapment

  • Surgical repair of orbital floor fracture.

  • Corticosteroids to reduce edema.

  • Cold compress and antibiotics if open wound.

6. CNS Causes

  • Stroke: Urgent stroke management (antiplatelets: Aspirin 160–325 mg orally once daily, statins, BP control).

  • MS/demyelination: Corticosteroids (Methylprednisolone 1 g IV daily × 3–5 days).

  • Intracranial tumor: Neurosurgical excision or radiotherapy.

Complications

  • Persistent double vision → impaired daily activities, risk of accidents.

  • Psychosocial distress.

  • Underlying life-threatening conditions (stroke, aneurysm, cancer).

  • Amblyopia in children with strabismus.

Prognosis

  • Isolated diabetic nerve palsy: Good, resolves spontaneously.

  • Myasthenia gravis, thyroid eye disease: Chronic, manageable with long-term treatment.

  • Cranial nerve palsy from aneurysm/tumor: Prognosis depends on timely surgical management.

  • Stroke/tumor-related: Prognosis depends on underlying disease severity.

Patient Education

  • Seek urgent care if double vision is sudden in onset, especially with headache, weakness, or slurred speech.

  • Do not drive until diplopia is corrected.

  • Use eye patch or prism lenses for temporary relief.

  • Strict control of diabetes, hypertension, and thyroid disease.

  • Attend follow-up with ophthalmologist and neurologist.




on

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)