CLINICAL

  POSTERIOR

PINPOINTING PAPILLEDEMA

DEFINITIVELY DIAGNOSE THIS CONDITION BY DETERMINING ITS CAUSE

OPTIC DISC swelling remains an intimidating clinical finding, particularly when it comes to distinguishing early papilledema from pseudopapilledema. Clinical similarities can lead to pseudopapilledema patients undergoing expensive and unnecessary medical testing, while those whose papilledema is initially mistaken for pseudopapilledema are at risk of death.

Here, I discuss the etiology, symptoms, clinical signs and management options for papilledema.

ETIOLOGY

Papilledema occurs when elevated increased intracranial pressure (ICP) is transmitted to the optic nerve sheath. This increased pressure mechanically disrupts axoplasmic flow within the optic nerve head (ONH). This disruption, in turn, leads to venous congestion, resulting in the characteristic “swelling” of the ONH, which represents a potentially life-threatening condition.

The most important risk factor for papilledema is a space-occupying intracranial mass or intracranial vascular lesion(s) (subarachnoid hemorrhage, carotid-cavernous fistula) requiring neuroimaging. Conversely, papilledema in the absence of a mass or lesion on brain imaging is idiopathic intracranial hypertension (IHH) or pseudotumor cerebri, commonly observed in obese females of childbearing age. Other risk factors for papilledema include: head trauma/injury, obstructive hydrocephalus, malignant hypertension, inflammation (sarcoidosis, multiple sclerosis), infiltrative disease of the ONH (leukemia, lymphoma), intracranial infection (meningitis, encephalitis), vascular issues (central retinal vein occlusion, anterior ischemic optic neuropathy, diabetic papillopathy) and medications (tetracycline, minocycline, lithium, nalidixic acid, corticosteroids and vitamin A derivatives).

In the early stage of papilledema, patients may not present with any complaints. However, if you suspect the condition, it’s important to go through a checklist of symptoms with the patient, as he or she may think these symptoms aren’t associated with their eyes and, therefore, may not mention them without being asked. For example, patients may hear a “whooshing” sound, which represents pulsatile tinnitus, a common finding associated with papilledema. Also, keep the patient’s general appearance and ocular, medical and medication history in mind.

Pseudopapilledema is apparent optic disc swelling secondary to other causes, such as buried ONH drusen (ONHD), hyperopic ONH (congenitally full disc), malinserted disc (oblique insertion) and tilted disc syndrome. Other causes include dysplastic ONH (morning glory syndrome), myelinated nerve fiber layer or dragged ONH observed in retinopathy of prematurity.

A.M., a 58-year-old male with chronic papilledema for one year on Diamox, presented for examination. His medical history was positive for hypertension, diabetes and hypercholesterolemia. Best-corrected vision was OD 20/20 and 20/20 OS. A dilated exam revealed the findings noted above. Humphrey Visual Field 24-2 test showed an enlarged blind spot OS and peripheral defects. The patient’s neurologist was advised of the findings, and the patient was scheduled for a three-month follow-up.

SYMPTOMS

• Headaches (worse upon waking or exacerbated by coughing or valsalva maneuvers, such as straining or bending)

• Nausea and vomiting

• Pulsatile tinnitus

• Normal vision (early papilledema)

• Vision loss (chronic papilledema)

• Visual field defects (enlarged blind spots or peripheral field loss in chronic papilledema)

• Focal neurological signs

◦ Diplopia - sixth nerve palsy

◦ Transient visual obscuration — precipitated by postural changes

• Decrease color perception

• Photopsias

CLINICAL SIGNS

• Blurring of disc margin

• Afferent pupillary defect (chronic asymmetric disease)

• Bilateral ONH hyperemia (asymmetrical presentation can occur, though it’s rare)

• Peripapillary hemorrhages (flame-shaped or disc splinter hemorrhages)

• Cotton wool spots

• Peripapillary halo

• Exudates

• Macular edema

• Venous congestion (vein dilation)

• Edema obscuring major vessels as they leave the disc

• Nerve fiber layer edema

• Folds (Paton’s folds: concentric, usually temporal, retinal folds that surround the disc or choroidal folds)

• Absent spontaneous venous pulse

• Late manifestations include:

◦ Retinochoroidal vessels (optociliary)

◦ Sheathing of peripapillary vessels

◦ Retinal pigmentary changes around the disc

◦ Pseudodrusen (disc gliosis)

◦ Optic atrophy

MANAGEMENT OPTIONS

After differentiating papilledema from pseudopapilledema, follow these three steps:

1. Identify the underlying cause. Based on the patient’s history, you may want to assess blood pressure. In addition, B-scan ultrasonography may be useful to rule out ONHD. Further, consider visual field testing (92083), fundus photography (92250) and fundus autofluorescence (out-of-pocket cost).

Scanning laser OCT (92134) is beneficial in differentiating ONHD (“lumpy-bumpy” internal contour) and ONH swelling (smooth internal contour with a “lazy V” pattern). Fluorescein angiography demonstrates increased dilation of the peripapillary capillaries with late leakage. Also, contemplate ordering lab testing for diabetes, inflammation or infection; and evaluate the scalp or temporal artery for tenderness to rule out ischemic optic neuropathy.

Urgent neuroimaging of the brain is crucial for the identification of an intracranial mass, or an intracranial vascular lesion, such as venous sinus thrombosis. If neuroimaging is normal, a lumbar puncture is necessary for the assessment of the opening pressure and to rule out infectious or neoplastic causes of cerebral spinal fluid (CSF).

In cases of IHH there is an opening pressure greater than 25cm (250mm) H2O with normal CSF composition and no associated secondary findings. Lumbar puncture may provide some therapeutic benefit, as the CSF pressure is reduced temporarily in papilledema patients.

2. Tailor treatment to the underlying cause. If an intracranial mass or intracranial vascular lesion is present, it should be addressed. In cases where the cause is medication, talk with the patient’s primary care doctor about withdrawing or decreasing the medication. In IHH cases, carbonic anhydrase inhibitors (acetazolamide; Diamox, Barr Laboratories) and other diuretics are often prescribed. Topamirate (Topamax, Janssen Pharmaceuticals, Inc.) is also used in IHH patients.

For obese patients, weight loss is highly recommended, as most of these patients improve after losing 5% to 10% of their total body weight. For inflammatory causes, such as sarcoidosis, steroids are beneficial. Treatment dosage and duration of use is relative to each patient. However, close monitoring is imperative, as steroid use can exacerbate the condition. Medical or surgical treatment, such as optic nerve sheath fenestration or a CSF diversion procedure (shunt), may be warranted when vision is threatened or other treatment options fail.

In most cases, papilledema takes six to 10 weeks to regress, following the lowering of ICP. However, persistent and/or chronic disease may present for months to years.

3. Schedule follow-up appointments. Clear communication and teamwork among all treating doctors is essential. In addition, patients should be evaluated every three to six months depending on the severity of the papilledema. Vision and serial visual fields are imperative.

PERFECTLY SWELL

Papilledema remains one of the most alarming signs in clinical practice. Proper evaluation not only can potentially save a patient’s life, but also reduce the need for expensive ancillary testing for a benign condition. As a result, be vigilant in definitively diagnosing this condition. OM

SHERROL A. REYNOLDS, O.D., F.A.A.O., is an associate professor at the Nova Southeastern University College of Optometry and clinical preceptor/attending in the college’s diabetes and macular clinic. She is a fellow of the Optometric Retina Society and chairperson for the Florida Optometric Association Healthy Eyes Healthy People Committee. Comment at tinyurl.com/OMcomment.