Neuro-ophthalmology Illustrated Chapter 9 – Disk Edema 1

Questions:
1. What is the term reserved for optic disk swelling with increased intracranial pressure?
2. Does pseudoedema of the optic disk have elevated optic nerve head?
3. Does pseudoedema of the optic disk have sharp margins?
4. Does pseudoedema of the optic disk have obscured vessels?
5. Does pseudoedema of the optic disk have a central cup?
6. Does pseudoedema of the optic disk have anomalous retinal vasculature?
7. Does pseudoedema of the optic disk leak on FA?
8. Does pseudoedema of the optic disk have peripapillary hemorrhages and exudates?
9. Does pseudoedema of the optic disk have venous dilation and tortuosity? 10. Does true disc edema of the optic disk have elevated optic nerve head?
11. Does true disc edema of the optic disk have sharp margins?
12. Does true disc edema of the optic disk have obscured vessels?
13. Does true disc edema of the optic disk have venous dilation and tortuosity?
14. Does true disc edema of the optic disk have anomalous retinal vasculature?
15. Does true disc edema of the optic disk have peripapillary hemorrhages and exudates?
16. Does true disc edema of the optic disk leak on FA?

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Questions with answers:
1. What is the term reserved for optic disk swelling with increased intracranial pressure?
Papilledema

2. Does pseudoedema of the optic disk have elevated optic nerve head?
Yes

3. Does pseudoedema of the optic disk have sharp margins?
Yes

4. Does pseudoedema of the optic disk have obscured vessels?
No

5. Does pseudoedema of the optic disk have a central cup?
It may or may not. If present it is usually very small.

6. Does pseudoedema of the optic disk have anomalous retinal vasculature?
Yes, abnormal retinal arterial branching.

7. Does pseudoedema of the optic disk leak on FA?
No

8. Does pseudoedema of the optic disk have peripapillary hemorrhages and exudates?
No

9. Does pseudoedema of the optic disk have venous dilation and tortuosity?
No

10. Does true disc edema of the optic disk have elevated optic nerve head?
Yes

11. Does true disc edema of the optic disk have sharp margins?
No

12. Does true disc edema of the optic disk have obscured vessels?
Yes

13. Does true disc edema of the optic disk have venous dilation and tortuosity?
Yes

14. Does true disc edema of the optic disk have anomalous retinal vasculature?
No

15. Does true disc edema of the optic disk have peripapillary hemorrhages and exudates?
Yes

16. Does true disc edema of the optic disk leak on FA?
Yes

The information below is from Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

9 Disc Edema
Edema of the optic nerve head, or disc edema, is a nonspecific term describing localized swelling anterior to the lamina cribrosa (▶Fig. 9.1).

9.1 Mechanisms of Optic Nerve Edema
Mechanisms of optic nerve edema include the following:
1. Local optic nerve injury, such as from inflammation (anterior optic neuritis or papillitis), ischemia (anterior ischemic optic neuropathy), fluctuations in intraocular pressure (high, as in acute glaucoma, or low, as in ocular hypotony), and toxicity
2. Blockage of retrograde axonal transport from optic nerve compression (optic nerve tumor or orbital mass) and raised intracranial pressure (papilledema)

9.2 Differentiating True Disc Edema from Pseudoedema
Differentiating true optic nerve head edema from pseudoedema is essential (▶Table 9.1, ▶Fig. 9.2 and ▶Fig. 9.3). In most cases, pseudoedema appearance results from a congenital anomaly of the optic nerve and does not require any workup, whereas true disc edema is associated with numerous concerning disorders.

9.3 Differential Diagnosis of Disc Edema
Disc elevation without true swelling:

● Optic disc anomalies
  ○ Myelinated nerve fibers (▶Fig. 9.4)

○ Drusen (▶Fig. 9.5)

 ○ Tilted disc
  ○ Crowded disc
● Optic disc infiltration
● Leber hereditary optic neuropathy

True disc swelling:
● Elevated intracranial pressure (papilledema) (▶Fig. 9.6)

● Inflammatory optic neuropathy (▶Fig. 9.7)

 ○ Demyelinating
○ Sarcoidosis or other inflammatory diseases
 ○ Infectious
● Neuroretinitis
● Vascular optic neuropathy
 ○ Anterior ischemic optic neuropathy (▶Fig. 9.8)

    – Nonarteritic
    – Arteritic
 ○ Diabetic papillopathy○ Central retinal vein occlusion (▶Fig. 9.9)

 ○ Carotid-cavernous fistula
 ○ Malignant systemic hypertension (▶Fig. 9.10)

● Compressive optic neuropathy
 ○ Neoplastic
    – Meningioma (▶Fig. 9.11)

    – Hemangioma
    – Lymphangioma
 ○ Non-neoplastic
   – Thyroid ophthalmopathy
   – Orbital inflammatory pseudotumor
● Infiltrative optic neuropathy
 ○ Neoplastic
   – Leukemia
   – Lymphoma
   – Glioma
 ○ Non-neoplastic
   – Sarcoidosis  
● Toxic
● Metabolic/nutritional deficiencies
● Traumatic optic neuropathy
● Intraocular hypotony (low intraocular pressure)

Reference: 1. Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

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