Papilledema - Optic Nerve Head Swelling

Papilledema, optic disc head swelling,

1. Papilledema Shreeji Shrestha

2. Hydrostatic noninflammatory swelling of optic disc secondary to increased ICP Optic Disc edema or Choked disc

3. Subarachnoid communication between brain and ON

4. Axoplasmic transport ON axoplasmic transport ( protein, chemicals, mitochondria) retrograde IOP (11-21mmhg) (Force) Tissue pressure at optic nerve (6-8mmHg) Retinal ganglion cell LGB (degraded and returned to Cell body) axons Orthograde

5. Blood flow depends on Vascular resistance, BP, IOP ONH blood flow - PP/R; PP is MABP-IOP

6. Etiology Primary - Idiopathic ICH/pseudo tumor cererbi Secondary - space-occupying lesion (midbrain, parietooccipital and cerebellum) ; cerebral edema; decrease in total volume within the cranial vault by thickening of the skull; Blockage of the flow of CSF (hydrocephalus); Reduced absorption of CSF or increased production

7. Idiopathic intracranial hypertension Risk factors – idiopathic, Obese female, pregnancy, endocrine disorders, drugs - tetracycline, nalidixic acid, amiodarone, lithium, corticosteroid in high dose, hypervitaminosis

8. Pathogenesis Mechanical theory - Hayreh theory – Inc CSF - ON tissue pressure – block axoplasmic transport (lamina) – venous congestion – swelling of RGC axons Ischemic theory - Vasomotor theory – inc ICP – Inc SVP – venous stasis – reduced perfusion of axons

9. Other hypotheses includes, direct infiltration of the optic nerve head by CSF, swelling of glia , absence of the restraining influence of Muller cells in the peripapillary retina, disequilibrium of hydrostatic pressure in the tissue and bloodstream, and compression of the central retinal vein as it traverses the subarachnoid space or cavernous sinus with elevated central venous pressure

10. 3 components increased and fluctuating pressure in the distal optic nerve sheath; elevated central retinal venous pressure; and impaired perfusion of the nerve fibers traversing the lamina cribrosa

11. Pathology neuronal swelling, venous and capillary dilatation, abnormal protrusion of the optic nerve head toward the vitreous, lateral displacement of the adjacent retina, and folds of the posterior retinal layers intra-axonal swelling is accompanied by an increase in mitochondria, disorganization of neurofilaments, intracellular membrane-enclosed bodies.

12. Development and resolution Papilledema takes over a week to develop, 2-8 hours (SAH) and resolve within hours, days or weeks depending on the way ICP is lowered Usually 6- 8 weeks after successful craniotomy Less than a week after ON sheath decompression 2-3 months in IIH

13. Unilateral papilledema Sheltering uninvolved eye from elevated pressure due to absence of subarachoid space around anterior portion of ON Congenital or acquired (scaring) Causes Foster kennedy syndrome Pseudo Foster kennedy syndrome

14. Pseudopapilloedema Hypermetropic eyes with small lamina cribosa and crowded nerve fibers Swelling isnot >2D, no venous engorgement, edema, blind spot not enlarged FA – no leakage

15. Features Headache - stretching of pain sensitive dura and pial vessels worse in awakening, Valsalva Transient blurring of vision – few sec, 20-30 times, ppt by bending posture Color vision – normal False localizing sign – lat rectus palsy due to inc ICP

16. Stages Early Established Chronic Atrophic

17. Early Established Chronic Atrophic Visual acuity normal Normal or diminised Variable VF decreased Impaired symptom Transient blurring of vis OD Nasal Blurring margin Mild hyperaemia Cup - present Severe disc hyperaemia Moderate disc elevation Indistinct margin with CWS, cup-obliterated Severe disc elevation, no CWS Cup- abs Dirty grey color(gliosis), elevated, indistinct margin background peripapillary nerve striations Retinal folds- paton lines, hemorrhage, Macular fan – imcomplete star Optociliary shunts and drusen like deposit- corpora amylacea Attenuated peripapillary vessels Venous pulsation(20) absent absent absent absent

18. Visual Field Defects Concentric enlargement of the blind spot (30%) – due to compression and lateral displacement of peripapillary retina Stiles - Crawford effect – peripapillary folds – light falls obliquely in retina central and arcuate scotomas

19. Papilledema Grading System ( Frisen Scale) Stage 0 Normal Optic Disc     no elevation of Radial nerve fiber layer    obscuration of a major blood vessel on the upper pole Stage 1 Very Early Papilledema    Obscuration of the nasal border of the disc    No elevation of the disc borders    Disruption of the normal radial NFL arrangement    Concentric or radial retrochoroidal folds

20. Stage 2 Early Papilledema    Obscuration of all borders     Elevation of the nasal border    Complete peripapillary halo Stage 3 Moderate Papilledema    Obscurations of all borders    Increased diameter of optic nerve head    Obscuration of one or more segments of major blood vessels leaving disc    Peripapillary halo irregular outer fringe with finger-like extensions Stage 4 Marked Papilledema    Elevation of the entire nerve head    Obscuration of all borders     Peripapillary halo     Total obscuration on the disc of a segment of a major blood vessel Stage 5 Severe Papilledema    Dome-shaped protrusions representing anterior expansion of the optic nerve head    Peripapillary halo    Total obscuration of a segment of a major blood vessel     Obliteration of the optic cup

21. Mechanical signs Vascular signs Blurring of the disc margin Filling in of the optic disc cup Anterior extension of the nerve head (3D = 1mm of elevation) Edema of the nerve fibre layer Retinal ( paton’s line) or choroidal folds or both Venous congestion of arcuate and peripapillary vessels Papillary and retinal peripapillary hemorrhages Nerve fiber layer infarcts Hyperemia of the optic nerve head Hard exudates of the optic disc

22. Chronic Papilledema

23. Postpapilledema Atrophy

24. Optic atrophy that results from chronic papilledema has a specific pattern of axonal loss. Loss of peripheral axons with sparing of central axons has been demonstrated in postmortem studies. Good central visual acuity despite severe papilledema and optic atrophy is found in most patients with chronic papilledema

25. In the Foster Kennedy syndrome, patients with frontal lobe or olfactory groove tumors develop the triad of optic atrophy in one eye; papilledema in the other eye; and anosmia

26. Diagnosis careful ophthalmoscopic examination Direct ophthalmoscopy – 3D - 1mm elevation difference of 2-6 D red-free ophthalmoscopy and slit lamp biomicroscopy Fluorescein angiography is often used to confirm early papilledema

27. CT scan – rule out IC lesions If MRI is contraindicated, pacemaker, metallic clip MRI of orbits - subarachnoid space becomes distended, the nerve sheath widens and there is flattening of the posterior sclera. prelaminar optic nerve may enhance and protrude anteriorly. Confocal scanning laser tomography - gradually increasing retinal surface elevation from the center of the disc to the disc margin, with a steeper contour nasally than temporally.

28. Differential Diagnosis Anomalously elevated optic disc   Intraocular inflammation Asymptomatic nonarteritic anterior ischemic optic neuropathy (e.g., diabetic papillopathy ) Hypertensive disc edema Optic neuritis, optic perineuritis ( perioptic neuritis) Infiltrative optic neuropathy (e.g., from leukemia) Compressive optic neuropathy (e.g., from optic nerve sheath meningioma)

29. LP and papilledema Usually contraindicated due to herniation of brain through foramen magnum – pressure in medulla - sudden death Guarded LP usually done Can be done in Pseudotumor cerebri CSF for investigations

30. Treatment Treat the underlying cause IIH medical– acetazolamide, Mannitol, corticosteroid surgery – repeated LP , decompression - if failure of medical treatment, progressive headache, progressive optic neuropathy; Direct fenestration of ONSD, Suboccipital craniectomy, subtemporal decompression, shunting procedure

31. Visual Prognosis more severe papilledema - worse visual prognosis Disc pallor with papilledema - indication of poor visual prognosis, even if ICP is lowered immediately, because the pallor is caused by loss of axons severe venous engorgement, retinal hemorrhages, and hard and soft exudates have no prognostic significance.

32. References Myron yanoff – neuroophthalomolgy Jacobiek - vol 3 neuroophthalmology Kanski Neuro-ophthalmology – A K khuruna