Optic Nerve Palsey/ Disorder Flashcards
What is it
Dysfunction of the optic nerve (cranial nerve II) leading to visual impairment or loss.
Clinical Features
• Decreased visual acuity (blurry vision or complete vision loss) 👀
• Loss of color vision (dyschromatopsia) 🌈
• Afferent pupillary defect (Marcus Gunn pupil) – pupil dilates instead of constricting with light
• Visual field defects (central scotoma, altitudinal loss)
• Optic disc changes (swelling in optic neuritis, pallor in chronic cases)
Epidemiology
Depends on the cause (e.g., optic neuritis, ischemic optic neuropathy)
More common in autoimmune diseases (e.g., multiple sclerosis)
Can be idiopathic or secondary to systemic conditions
Age groups affected
Young adults (20–40 years) – More likely optic neuritis (e.g., multiple sclerosis)
Elderly (>50 years) – More likely ischemic optic neuropathy (e.g., due to hypertension, diabetes)
Risk factors
✅ Modifiable:
Smoking 🚬
Hypertension & diabetes 🍔
Obesity ⚖️
Vitamin deficiencies (B12 deficiency)
Excessive alcohol intake 🍷
🚫 Non-Modifiable:
Autoimmune diseases (Multiple Sclerosis, Lupus)
Giant cell arteritis (in older adults)
Genetic conditions (Leber’s hereditary optic neuropathy)
Clinical presentation
🔹 Optic Neuritis (Common in MS)
Sudden vision loss (one eye)
Pain with eye movement
Color desaturation (red appears dull)
🔹 Ischemic Optic Neuropathy (Common in elderly)
Painless, sudden vision loss
Associated with vascular risk factors (hypertension, diabetes)
🔹 Compressive Optic Neuropathy (Tumors, Trauma)
Gradual vision loss
May have headache, proptosis (bulging eye)
Prognosis
Depends on cause
- Optic neuritis: Often improves with steroids, but recurrence possible
- Ischemic optic neuropathy: Partial recovery, but vision loss can be permanent
- Compressive lesions: Requires surgery/radiotherapy, prognosis depends on severity
🔹 Prevention: Manage underlying conditions, routine eye exams, avoid smoking
Test
Snellen wall chart
Visual fields test
Pupillary reflexes
