The Normal Optic Disc Cup-to-Disc Ratio (C/D) Papilledema vs. Pseudopapilledema

Robert L. Tomsak, MD, PhD Professor of Ophthalmology and Neurology • O.4 on average with Gaussian distribution and less than 5% with C/D = 0.7 or greater Wayne State University School of Medicine • Physiologic cups tend to be symmetric between both eyes with an Specialist in Neuro-ophthalmology interocular C/D > 0.2 about 1% of the time Kresge Eye Institute • Blacks have larger C/D than whites Detroit, MI • Cup size may increase slightly with age

Papilledema and Pseudopapilledema Papilledema*: Definition Optic Disc Edema w/o Increased ICP • In both cases the optic disc is elevated • Optic neuritis (papillitis) • Leber’s hereditary Optic disc edema secondary to • In papilledema the nerve is elevated because it is swollen, or •AION optic neuropathy edematous because of increased intracranial pressure increased • Partial CRVO • Diabetic papillopathy intracranial pressure • However, not every swollen or edematous optic nerve is the result of • Infiltration of nerve: eg, • Hypertensive disc increased intracranial pressure sarcoid, leukemia edema • Compression of * In the old days the optic disc was called the “papilla”; •In pseudopapilledema the nerve is elevated for structural reasons that intraorbital optic nerve: • Amiodarone optic edema is the abnormal accumulation of fluid in tissues or do not involve swelling or edema and therefore is not necessarily eg, ONSM, ONG neuropathy body cavities; in other words, it is reflective of reflective of a disease process a disease process

Optic Nerve Orbital Anatomy Back to Papilledema… Histopathology of Papilledema

Displacement The brain and spinal cord Are bathed in cerebrospinal of photo- fluid at a certain pressure receptors

Retinal Fold

Subarachnoid Space Frisen Grades of Mechanisms of Papilledema Most Common Cause of Papilledema in Ambulatory Population “Swelling of the Optic Nerve Head” is Idiopathic Intracranial Hypertension • Grade 1: C-shaped blurring of nasal, (aka Pseudotumor Cerebri)* superior and inferior margins of disc; temporal margin normal. • Modified Dandy Criteria • Grade 2: 360-degree elevation of the disc – Presence of signs and symptoms of increased intracranial pressure margin

– Absence of localizing neurologic findings except as they relate to • Grade 3: Elevation of entire disc with elevated ICP partial obstruction of one or more of the retinal vessels at the disc margin – Normal mental status – Normal neuro-imaging (eg, normal ventricles, no evidence of brain • Grade 4: Complete obliteration of cup and complete obscuration of at least some of the tumor) vessels on the surface of the disc

– No other cause of increased intracranial pressure present • Grade 5: Dome-shaped appearance with all vessels being obscured (“champagne cork” * But this must be a diagnosis of exclusion Axoplasmic Transport papilledema)

Other Signs Consistent With Papilledema Unilateral or Asymmetric Papilledema How else can we evaluate the Optic Disc?

In IIH about 10% of cases have asymmetric • Fundus Photography swelling - a difference •IVFA Flame shaped hemorrhages Intraretinal exudates of at least two grades of papilledema • OCT • FAF • B-scan Ultrasound

Intraretinal hemorrhages Paton’s lines

OCT in Papilledema

IVFA in Papilledema

Despite high-grade papilledema for over 4 months, GCL+IPL thickness and visual fields are are preserved OU!

Chronic Papilledema from IIH/PTC Signs of Chronic Papilledema

• Milky-gray color to optic disc • Drusen-like changes within disc substance • Drop-out of NFL • Choroidal neovascular membranes (rare)

PLoS ONE, 2012. Vol 7, Issue 5, e36965

Visual Field Defects in Papilledema from Idiopathic Postpapilledema Optic Atrophy Intracranial Hypertension (Pseudotumor Cerebri)

Enlarged Blind Spot Arcuate • Takes weeks to develop Defects Diffuse • Attenuation of retinal vessels Constriction

• Shunt vessel formation Ceco- Central • Peripheral nerve fibers drop out before Inferonasal Scotomas Step papillomacular bundle fibers

In spite of fairly decent RNFL Measurements, there is severe GCL+IPL thinning

Pseudopapilledema vs. True Papilledema Ophthalmoscopic Features of J.L. Smith “The Optic Nerve” ~ 1975 Pseudopapilledema Pseudopapilledema Findingg Pseudo True SVP Yes No • Elevated disc; margins • May have spontaneous • Structural congestion • Dysplastic optic discs, obscured venous pulse e.g. Hemorrhagesg No Yes • Drusen of optic disc • Absence of physiologic • May see disc drusen – Megalopapilla cup (“hyaline bodies”) • Tilted optic discs Retinal Striae No Yes – Morning Glory Enlargedg BS No Yes • Vascular anomalies with • Hemorrhages rare • Dragged disc (in ROP) syndrome increased branching • No exudates TVO No Yes • Myelinated nerve • Normal nerve fiber layer; • No nerve fiber layer fibers FluoroLeakageg No Yes disc transilluminates infarcts • Glial veil Other Neuro No Yes

High Hypermet Yes No Pseudopapilledema “Little Red Discs” Pseudopapilledema with Structural Congestion • Structural congestion

Pseudopapilledema with Pseudopapilledema with Segmental Elevation Tortuous Retinal Vessels Pseudopapilledema - J.H.

Pseudopapilledema with Midline Facial Defects are often Associated Pseudopapilledema with Tilted Disc With Dysplastic Optic Nerves Anomalous Retinal Vessels Glial Veil Pseudopapilledema with “Dragged” Disc Myelinated Nerve Fibers

Drusen Visible Optic Disc Drusen ON Drusen and Visual Field Defects

• Druse /Drusen - German for crystals • Two types: macular drusen and optic disc drusen • Are not the same histologically • Buried optic disc drusen – Look at parents’ optic discs – Use red-free light on ophthalmoscope

ON Drusen can cause visual field defects that are indistinguishable from glaucoma

Pseudopapilledema with Buried Drusen Optic Nerve Drusen Visible on CT scan

Fundus autofluorescence shows abnormalities consistent with optic disc drusen Abnormal RNFL thickness is probably an artifact Papilledema and Pseudopapilledema Disc Drusen Associated CNVM - After Laser Summary Treatment • In both cases the optic disc is elevated

• In papilledema the nerve is elevated because it is swollen, or edematous because of increased intracranial pressure

• However, not every swollen or edematous optic nerve is the result of increased intracranial pressure

• In pseudopapilledema the nerve is elevated for structural reasons that do not involve swelling or edema and therefore is not necessarily reflective of a disease process

• Current ophthalmic imaging techniques are often crucial for the differentiation of these two conditions