Figure 4-3 Patterns of visual field loss in optic neuropathies. A, Cecocentral scotoma (left; arrow); paracentral scotoma (right; arrow). B, Central scotoma (arrow). C, Arcuate scotoma (arrow). D, Broad arcuate (altitudinal) defect (arrow). E, Nasal arcuate (step) defects (arrows). F, Enlarged blind spot (arrow). (Parts E, F courtesy of Anthony C. Arnold, MD.)
Table 4-2
Anterior Optic Neuropathies With Optic Disc Edema
Acute papilledema
Papilledema refers to edema of the optic nerve head that results from increased intracranial pressure (ICP). The papilledematous disc is indistinguishable from disc edema resulting from other causes. Acute papilledema produces hyperemia of the optic disc, with dilation of the existing disc surface capillary net, and telangiectasia of the surface and radial peripapillary vessels. The edematous peripapillary retinal nerve fiber layer (NFL) is grayish white and opalescent, with feathered, striated margins that obscure the disc edge and retinal vessels coursing through it. Early papilledema begins at the superior and inferior poles of the optic disc. As papilledema worsens, it encompasses the nasal optic disc, creating a c-shaped area of disc edema with the opening along the temporal rim. Later, the edema involves the entire optic disc and results in blurring of major vessels off the optic disc head. Late findings include absence of the physiologic cup and obscuration of vessels on the disc itself. Absence of spontaneous venous pulsations may reflect increased ICP, but absence at initial examination is of limited value; 20% of the general population does not have spontaneous venous pulsations. Their disappearance after prior documented presence, however, suggests ICP elevation. Other ophthalmoscopic findings may include disc and retinal cotton-wool spots, exudates, and hemorrhage.
Most patients with elevated ICP have symptoms such as headache, nausea, and vomiting. Patients may also note transient visual obscurations—episodes of unilateral or bilateral vision loss lasting seconds. These episodes are described as “grayouts,” “whiteouts,” or “blackouts” of vision, often occurring with orthostatic changes. In acute papilledema, optic nerve function, including visual acuity
and color vision, is usually normal. Pupillary responses are also normal; visual fields demonstrate only enlargement of the blind spot.
The clinician’s first step in managing suspected papilledema is to rule out pseudopapilledema. The following funduscopic features suggest true acquired disc edema:
hyperemia
microvascular abnormalities on the disc surface such as telangiectasis or flame hemorrhages opacification of the peripapillary retinal NFL
Most cases of pseudopapilledema result from optic disc drusen (Fig 4-4; also see discussion below.)
Figure 4-4 A, Fundus photograph of the optic disc with buried drusen. The disc margin is blurred, with yellowish opacity of the deep peripapillary tissue. The retinal vessels are clearly visible overlying the disc. B, Fundus photograph of the optic disc with papilledema. The disc margin is blurred, with grayish white, opalescent thickening of the peripapillary nerve fiber layer (arrow). The retinal vessels are partially obscured at the disc margin and within the peripapillary retina. There are exudates just temporal to the disc from chronic edema. C, Surface drusen demonstrate prominent refractile nodules on the disc surface, which do not obscure retinal vessels. D, Astrocytic hamartomas are nodular masses arising from
peripapillary retina and obscure the retinal vessels. (Parts A, B courtesy of Sophia M. Chung, MD; parts C, D reprinted from Arnold AC. Optic disc drusen. Ophthalmol Clin North Am. 1991;4:505–517.)
Other causes of an elevated disc appearance mimicking papilledema are hyaloid remnants and glial tissue on the disc surface, congenital “fullness” of the disc associated with entry of the optic nerve into the eye through a relatively small scleral canal, and disc fullness associated with hyperopia. Vitreopapillary traction can cause a swollen-appearing optic disc. Obscuration of disc margins can occur without disc elevation from myelination of the NFL (Fig 4-5). Myelination typically occurs at the disc margin, where it obscures the disc–retina border; myelination in the NFL also obscures the retinal vessels and results in a feathered edge that resembles true edema. Myelination appears as a dense, white opacity compared with the partially translucent, grayish white appearance of true edema.
Figure 4-5 Myelinated nerve patches are often present within the arcuate bundles, occasionally abutting the disc. When they are contiguous, these nerve patches may be mistaken for disc edema or cotton-wool spots. (Courtesy of Anthony C.
Arnold, MD.)
Papilledema may result from a variety of conditions, including an intracranial mass, hydrocephalus, central nervous system (CNS) infection, infiltration by a granulomatous or neoplastic process, cerebral venous thrombosis or pseudotumor cerebri (discussed later in the chapter). Suspicion of papilledema warrants urgent neuroimaging to rule out an intracranial mass lesion and
venous thrombosis. Normal imaging results should prompt evaluation of the cerebrospinal fluid (CSF) opening pressure and composition.
Chronic papilledema
Optic nerve function may deteriorate in patients with chronically elevated ICP (lasting months to years) and long-standing papilledema. The disc may no longer appear hyperemic but appears pale as the result of chronic axonal loss (Fig 4-6). Additional features may include
Gliosis of the peripapillary NFL. The opacification appears grayish, less “fluffy,” and more membranous than with edema. Gliosis tends to follow retinal vessels, producing vascular sheathing.
Optociliary shunt vessels (retinochoroidal collaterals), preexisting venous channels on the disc surface that dilate in response to chronic central retinal vein obstruction from elevated ICP. Unlike the retinal vascular anomalies often accompanying drusen and congenital disc anomalies, these collateral vessels follow an evolving course of enlargement over time and characteristically dive deep into the choroid immediately adjacent to the disc.
Refractile bodies of the disc, the result of chronic lipid-rich exudation (Fig 4-7). Unlike drusen, these bodies tend to be smaller and noncalcified, remaining on the disc surface rather than within its substance, with frequent clustering at the disc margin; they disappear as papilledema resolves.
Figure 4-6 Chronic atrophic papilledema with gliosis and retinal vascular sheathing. (Courtesy of Anthony C. Arnold, MD.)
Figure 4-7 A, B, Optic discs in chronic papilledema, with the development of refractile bodies (arrows) representing lipid exudates from chronic microvascular leakage. C, D, Visual field patterns confirm the presence of mild diffuse depression
in sensitivity and superior and inferior arcuate defects. (Parts A, B courtesy of Anthony C. Arnold, MD; parts C, D courtesy of Steven A. Newman, MD.)
With chronic papilledema, visual field defects may include nasal field loss, arcuate scotomata, and generalized peripheral depression. Central visual field involvement with decreased visual acuity typically does not occur until late. The process is usually bilateral, but an RAPD may occur if asymmetric.
Arnold AC. Differential diagnosis of optic disc edema. Focal Points: Clinical Modules for Ophthalmologists. San Francisco: American Academy of Ophthalmology; 1999, module 2.
Idiopathic intracranial hypertension
Patients with idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, present with symptoms and signs of elevated ICP. Headache and nausea are common. Other symptoms may include transient visual obscurations, diplopia (secondary to abducens nerve paresis), visual field loss, and pulsatile tinnitus (pulse synchronous bruit). Almost all patients with IIH have papilledema.
Other neurologic abnormalities other than abducens palsy are not associated with IIH. As discussed above for acute papilledema, early IIH shows normal visual acuity and enlarged blind spots on perimetry testing. Optic nerve function may deteriorate in long-standing, untreated, or severe cases.
The incidence of IIH peaks in the third decade of life. Ninety percent of patients are women and 90% are obese. The disease is rare in prepubertal children (with obesity less a factor) and in lean adults. Intracranial hypertension is associated with the use of exogenous substances such as vitamin A (>100,000 U/day), tetracycline, minocycline, doxycycline, retinoic acid, and lithium, as well as the use of or withdrawal of use from corticosteroids. Sleep apnea may be associated with IIH. Although hormonal changes such as occur during pregnancy and from hormonal abnormalities have been implicated, IIH has not been definitely associated with any specific endocrinologic dysfunction. The mechanism for the increase in ICP in idiopathic IIH remains obscure.
Cerebral venous disorders such as cerebral venous obstruction (resulting from trauma, childbirth, a hypercoagulable state, or a middle ear infection), systemic or localized extracranial venous obstruction (eg, after radical neck dissection), a dural arteriovenous malformation, or systemic vasculitis may lead to decreased venous outflow and thus increased ICP. Such conditions may resemble IIH, and therefore patients with suspected IIH should undergo not only neuroimaging with magnetic resonance imaging (MRI) to rule out tumor, hydrocephalus, and meningeal lesion, but also magnetic resonance venography (MRV) to assess for venous sinus occlusion (see Chapter 2, Fig 2- 13). Characteristic MRI findings of intracranial hypertension include flattening of the globe, enlarged optic nerve sheaths, partially empty sella, and narrowing of the distal transverse sinus. Lumbar puncture should always be performed to confirm elevated ICP and to rule out infectious or inflammatory processes. Table 4-3 gives the diagnostic criteria of IIH.
Table 4-3
The ophthalmologist plays a crucial role in the management of IIH. Careful long-term follow-up is essential to ensure that papilledema resolves. Regularly scheduled examinations should include testing of visual acuity, color vision, and quantitative perimetry to document the level of optic nerve function. Stereophotographs of the optic nerve are essential to obtain during patient follow-up. The frequency of visual field testing depends on the severity of papilledema, the level of optic nerve dysfunction, and the response to treatment.
Treatment for IIH depends on symptomatology and vision status. The disease may be self-limited. If headache is controlled with minor analgesics and optic nerve dysfunction is absent, no therapy may be required. However, the natural history of IIH may result in severe vision loss; 26% of patients in a long-term study eventually had visual acuity worse than 20/200 in at least 1 eye. For obese patients, weight loss can be an effective treatment and is always recommended, as weight loss alone can lead to resolution of IIH. In some cases, bariatric surgery has been considered. For patients requiring medical therapy, acetazolamide is usually the first choice; topiramate has also been used with success. Topiramate has multiple beneficial effects—headache control, appetite suppression, and carbonic anhydrase inhibition. Furosemide is frequently used in patients intolerant of acetazolamide
or topiramate. The use of corticosteroids is controversial. Although ICP can improve with use of corticosteroids, recurrence can occur commonly during corticosteroid taper; indeed, corticosteroid withdrawal is a documented cause of IIH. However, a short course of high-dose intravenous corticosteroids may benefit the patient with fulminant papilledema and severe vision loss. Repeat lumbar punctures are not recommended therapy.
In cases of intractable headache or progressive vision loss despite maximally tolerated medical therapy, surgical therapy is recommended. In some patients with severe vision loss and papilledema from markedly elevated ICP, surgical intervention may be considered without waiting for definite evidence of progression. The primary surgical options are optic nerve sheath fenestration (ONSF) or a CSF diversion procedure (lumboperitoneal or ventriculoperitoneal shunt).
In the presence of substantial loss of vision without prominent headache, ONSF may represent the preferred surgical option because it directly protects the optic nerve and has lower morbidity than that associated with shunting. However, ONSF carries a 1%–2% risk of vision loss from optic nerve injury, central retinal artery occlusion (CRAO), or central retinal vein occlusion (CRVO). It does not lower ICP and thus often does not treat headache. A reduction of papilledema in the contralateral eye can occur, but bilateral ONSF may be required. The long-term success rate of ONSF remains unclear. Repeat ONSF may be performed but is technically more difficult because of scarring.
Lumboperitoneal or ventriculoperitoneal shunting procedures effectively lower ICP, with improvement of headache, abducens palsy (if present), and papilledema; moreover, shunting entails no direct risk to the optic nerve. A shunt, however, may become occluded, infected, or altered in position, requiring reoperation in many cases. Among patients with morbid obesity, gastric bypass surgery can effectively reduce both weight and ICP.
IIH also occurs in the pediatric population, but the criteria for pediatric IIH remain controversial. Although the term pediatric typically refers to children under the age of 18 years, some authors believe it should be reserved for prepubescent children. IIH appears to be a different disorder in prepubertal children, with a predilection for boys and nonobese children. Unlike in adult IIH, several cranial neuropathies have been associated with pediatric IIH that reverse with lowering of the ICP; these include neuropathies of cranial nerves (CNs) III, IV, VI, VII, IX, and XII. In 2010 and 2011, 2 studies showed that normal opening pressure among children is higher than previously believed and is similar to that in adults. Papilledema without headache or visual symptoms is more common in younger patients. The treatment for pediatric IIH is similar to that for adult IIH.
Avery RA, Shah SS, Licht DJ, et al. Reference range for cerebrospinal fluid opening pressure in children. N Engl J Med. 2010;363(9):891–893.
Bruce BB, Biousse V, Newman NJ. Update on idiopathic intracranial hypertension. Am J Ophthalmol. 2011;152(2):163–169. Epub 2011 Jun 21.
Sinclair AJ, Burdon MA, Nightingale PG, et al. Low energy diet and intracranial pressure in women with idiopathic intracranial hypertension: prospective cohort study. BMJ. 2010;341:c2701.
Anterior ischemic optic neuropathy
Anterior ischemic optic neuropathy (AION) is the most common acute optic neuropathy in patients more than 50 years of age. Patients experience painless monocular vision loss that develops over hours to days. Visual acuity may be diminished, but visual field loss always occurs; altitudinal and other variants of arcuate defects are most common, although any defect may also occur. An RAPD is present unless the optic neuropathy is bilateral. Optic disc edema develops at onset and may precede the vision loss.
AION is classified as either arteritic (AAION), in which case it is associated with vasculitis, most commonly giant cell arteritis (GCA), or nonarteritic (NAION) (Table 4-4). The most important initial step in evaluating AION is to distinguish between these causes.
Table 4-4
Arteritic anterior ischemic optic neuropathy AAION is less frequent (5%–10% of AION cases) than NAION and usually occurs in older patients (mean age, 70 years). It is caused by inflammatory and thrombotic occlusion of the short posterior ciliary arteries. Systemic symptoms of GCA are usually present, including headache, scalp tenderness, malaise, anorexia, weight loss, and fever. Jaw claudication, the most specific symptom, describes masseter muscle pain or fatigue that occurs with prolonged chewing. The symptom worsens until chewing stops and resolves over minutes. Occult GCA, defined as either elevated erythrocyte sedimentation rate (ESR) without systemic symptoms or normal ESR in the presence of systemic symptoms, may occur in up to 20% of patients with AAION. Transient vision loss preceding AION may indicate GCA.
Vision loss is typically severe (visual acuity is <20/200 in >60% of patients), and no light perception vision should prompt an aggressive evaluation for GCA. Funduscopic clues to a diagnosis of AAION over NAION include the following:
chalky white optic disc edema (in NAION the disc is often hyperemic) (Fig 4-8)
cotton-wool spots away from the optic disc indicative of concurrent retinal ischemia (cottonwool spots on or adjacent to the optic disc can be present in NAION)
delayed choroidal filling on fluorescein angiographic studies (normally, the choroid fills completely within 3–5 seconds, before retinal arteries) (Fig 3-7)
normal or large cup in the fellow eye (in NAION, a small cup–disc ratio is common)
Figure 4-8 A, Optic disc appearance in nonarteritic AION. Edema is segmental, with mild superimposed pallor and flame hemorrhages. B, The fellow eye demonstrates a characteristic crowded appearance, which has been called “disc at risk.” C, Optic disc appearance in arteritic AION. Pallor is more pronounced. D, The fellow eye demonstrates a normal cup–disc
ratio. Lack of a disc at risk should suggest an arteritic AION. (Parts A, B courtesy of Michael S. Lee, MD; parts C, D courtesy of Rod Foroozan, MD.)
When AAION is suspected, immediate initiation of high-dose corticosteroid therapy is crucial. Adjunctive daily aspirin can also be added. Confirmational temporal artery biopsy may be delayed for 7–10 days without compromising test results. Intravenous methylprednisolone (1 g/day for the first 3–5 days) is most often recommended, after which oral prednisone (1 mg/kg/d) may be used (up to 100 mg/day, tapered slowly over 3–12 months or more, depending on response). Alternate-day corticosteroid therapy is inadequate for AAION.
The major goal of AAION therapy (apart from avoiding systemic vascular complications) is to prevent contralateral vision loss. Untreated, the fellow eye becomes involved in up to 95% of cases,
within days to weeks. Although the initially affected eye may improve somewhat, recovery does not generally occur. The risk of recurrent or contralateral optic nerve involvement during corticosteroid withdrawal has been reported at 7%; thus, tapering must be done slowly and carefully. Recurrent symptoms or elevation of ESR should prompt reevaluation for disease activity.
For a discussion of systemic effects of, diagnostic evaluation of, and therapy for GCA, see Chapter 14.
Lee AG, Brazis PW. Giant cell arteritis. Focal Points: Clinical Modules for Ophthalmologists. San Francisco: American Academy of Ophthalmology; 2005 module 6.
Parikh M, Miller NR, Lee AG, et al. Prevalence of a normal c-reactive protein with an elevated erythrocyte sedimentation rate in biopsy-proven giant cell arteritis. Ophthalmology. 2006;113(10):1842–1855. Epub 2006 Aug 1.
Scheurer RA, Harrison AR, Lee MS. Treatment of vision loss in giant cell arteritis. Curr Treat Options Neurol. 2012;14(1):84– 92.
Nonarteritic anterior ischemic optic neuropathy The nonarteritic form of AION is more common (accounting for 90%–95% of AION cases) and occurs in a relatively younger age group (mean age, 60 years) than the arteritic form. The annual incidence is approximately 80/100,000. NAION presumably relates to compromised optic disc microcirculation in eyes with structural “crowding” of the disc. Histologic studies show the area of infarction is located within the scleral canal alone, supporting the compartment syndrome theory. Patients frequently report visual impairment upon awakening. The initial course may remain static, in which vision loss is stable from onset, or become progressive, which involves either episodic, stepwise decrements or a steady decline of vision over weeks to months before eventual stabilization. The progressive form has been reported in 22%–37% of NAION cases. No systemic symptoms are typically associated with NAION.
Vision loss is usually less severe than in AAION (visual acuity >20/200 in >60% of cases). The most common pattern of visual field loss is altitudinal defects, but any pattern may be seen. The optic disc edema in NAION may be diffuse or segmental and hyperemic or pale (see Fig 4-8). The optic disc in the contralateral eye is typically small in diameter and demonstrates a small or absent physiologic cup (“disc at risk”).
The optic disc usually becomes visibly atrophic within 6–8 weeks; persistence of edema past this point could suggest an alternative diagnosis. The 5-year risk of contralateral involvement is 15%. Occurrence in the second eye produces the clinical appearance of “pseudo–Foster Kennedy syndrome,” in which the previously affected disc is atrophic and the currently involved nerve head is edematous. Both eyes show visual field loss characteristic of AION. This is in contrast to the true Foster Kennedy syndrome, secondary to intracranial mass, in which 1 optic disc is atrophic because of chronic compression by the mass, whereas the other disc is edematous because of elevated ICP.
NAION is associated with the following factors: structural crowding of the disc (disc at risk), systemic hypertension, diabetes mellitus (particularly in young patients), and hyperlipidemia. Neither carotid occlusive disease nor prothrombotic disorders is a proven risk factor. Hypercoagulable disorders, sleep apnea, and nocturnal hypotension may be associated but remain currently unproven. One suggested association is with phosphodiesterase inhibitors (eg, sildenafil), presumably because of their hypotensive effect, although causation has not been proven.
NAION must be differentiated from optic neuritis (Table 4-5). In unclear cases, contrast-enhanced MRI can help in the differentiation. The affected optic nerve appears normal in NAION (95%) but enhances with use of gadolinium contrast in optic neuritis (90%).
Table 4-5
Untreated NAION generally remains stable after reaching the low point of visual function, but improvement of at least 3 lines of Snellen visual acuity was reported in 31% of patients after 2 years in the Ischemic Optic Neuropathy Decompression Trial (IONDT). Recurrent episodes of vision loss in the same eye after 3 months are unusual in NAION (up to 6.4%), occurring most often in young patients.
There is no proven therapy for NAION. The IONDT showed no benefit of ONSF for NAION, and this surgical option has therefore been abandoned as a treatment modality. Neuroprotective drugs have demonstrated beneficial effects against secondary neuronal degeneration in animal models of ischemic retinal ganglion cell damage and optic nerve crush injury; however, clinical studies have been unsuccessful in recruiting sufficient numbers of patients in a timely manner. One study examined treatment of patients with oral prednisone, 80 mg daily for 2 weeks, followed by a slow taper over several weeks. This retrospective evaluation of almost 700 patients showed improvement in visual acuity and visual fields only among patients with visual acuity of 20/70 or worse. This treatment remains controversial given the potential biases in the study methodology.
There is also no proven prophylaxis for the fellow eye. Although aspirin has a proven effect in reducing the risk of secondary stroke, its role in reducing the incidence of fellow eye involvement after the initial episode remains unproven.
Arnold AC. Pathogenesis of nonarteritic anterior ischemic optic neuropathy. J Neuroophthalmol. 2003;23(2):157–163.
Hayreh SS, Zimmerman MB. Non-arteritic anterior ischemic optic neuropathy: role of systemic corticosteroid therapy. Graefes Arch Clin Exp Ophthalmol. 2008;246(7):1029–1046. Epub 2008 Apr 11.
Lee MS, Grossman D, Arnold AC, Sloan FA. Incidence of nonarteritic anterior ischemic optic neuropathy: increased risk among diabetic patients. Ophthalmology. 2011;118:959–963.
Newman NJ, Scherer R, Langenberg P, et al; Ischemic Optic Neuropathy Decompression Trial Research Group. The fellow eye in NAION: report from the ischemic optic neuropathy decompression trial follow-up study. Am J Ophthalmol. 2002;134(3):317–328.
Rizzo JF III, Andreoli CM, Rabinov JD. Use of magnetic resonance imaging to differentiate optic neuritis and nonarteritic anterior ischemic optic neuropathy. Ophthalmology. 2002;109(9):1679–1684.
Optic neuritis
Optic neuritis generally affects the retrobulbar portion of the optic nerve (with a normal optic disc appearance). In approximately one-third of optic neuritis cases, the inflammation involves the anterior portion and the optic disc appears edematous, so the term papillitis applies. The disc edema is usually hyperemic and diffuse. Papillitis is more common in postviral and infectious neuritis than in demyelinating neuritis, but considerable overlap exists. Children, in particular, manifest postviral optic neuritis and papillitis, which most commonly presents with bilateral profound vision loss. Among adults, the management of optic neuritis is similar whether optic disc edema is present or not (see the discussion later in the chapter).
In the 15-year follow-up to the Optic Neuritis Treatment Trial (ONTT), multiple sclerosis (MS) did not develop in patients who had normal MRI findings and severe papillitis, peripapillary
hemorrhages, or retinal exudates (see Chapter 14).
Beck RW, Trobe JD, Moke PS, et al; Optic Neuritis Study Group. High and low-risk profiles for the development of multiple sclerosis within 10 years after optic neuritis: experience of the optic neuritis treatment trial. Arch Ophthalmol. 2003;121(7):944–949.
Optic Neuritis Study Group. Multiple sclerosis risk after optic neuritis: final optic neuritis treatment trial follow-up. Arch Neurol. 2008;65(6):727–732.
Neuroretinitis
Neuroretinitis is a clinical entity characterized by acute loss of vision associated with disc edema and a star pattern of exudates in the macula (Fig 4-9). Mild vitritis and choroidal lesions may also occur. The diffuse disc edema spreads through the outer plexiform layer along the papillomacular bundle and around the fovea. As the fluid resorbs, the lipid precipitates in a characteristic radial pattern in the Henle layer. The macular star can appear at initial presentation or several days later. Recognizing fluid or lipid exudates in the papillomacular bundle is crucial for establishing the correct diagnosis and differentiating neuroretinitis from optic neuritis, as patients with neuroretinitis do not have an increased risk of multiple sclerosis. Patients with neuroretinitis may have elevated IgM titers for Bartonella quintana or B henselae—the most common cause of neuroretinitis and cat-scratch disease. No definitive evidence exists that corticosteroids and antibiotics reduce the impact of ocular bartonellosis causing neuroretinitis. Other potential infectious and inflammatory causes include syphilis, Lyme disease, sarcoidosis, toxoplasmosis, tuberculosis, and viruses; therefore, serologic testing for specific infections should be considered in cases of neuroretinitis. See BCSC Section 9, Intraocular Inflammation and Uveitis, for a complete discussion of ocular bartonellosis and neuroretinitis.
Figure 4-9 A 23-year-old man with a 2-day history of blurred vision on the right (visual acuity: 20/40 OD, 20/20 OS). A, The optic disc on the right side is elevated and hyperemic, with obscuration of the nerve fiber layer. B, 5 weeks after onset, funduscopic examination shows a macular star, characteristic of neuroretinitis. Optic disc edema is now less prominent.
(Courtesy of Steven A. Newman, MD.)
Chi SL, Stinnett S, Eggenberger E, et al. Clinical characteristics in 53 patients with cat scratch optic neuropathy. Ophthalmology. 2012;119(1):183–187. Epub 2011 Sep 28.
Diabetic papillopathy
Diabetic papillopathy occurs in patients with either type 1 or type 2 diabetes mellitus. Patients may
have no symptoms or have nonspecific symptoms of “blurred vision” or “distortion” without pain. Evidence of optic nerve dysfunction (through testing of visual acuity and visual field and for an RAPD) is variable. The optic nerve reveals hyperemic edema, but 50% of patients show marked dilation of the disc surface microvasculature (Fig 4-10) that appears similar to neovascularization of the disc (NVD). The vessels in NVD proliferate into the vitreous cavity and leak fluorescein into the vitreous in angiographic studies. Diabetic retinopathy is not universal among patients with papillopathy (63%–80%), and the absence of retinopathy does not preclude a diagnosis of diabetic papillopathy.
Figure 4-10 Optic disc in diabetic papillopathy shows disc edema with prominent surface telangiectasia. (Reprinted from
Arnold AC. Differential diagnosis of optic disc edema. Focal Points: Clinical Modules for Ophthalmologists. San Francisco: American Academy of Ophthalmology; 1999, module 2.)
Bilateral diabetic papillopathy warrants investigation to rule out papilledema associated with elevated ICP. Untreated, the dilated, radially oriented vessels and disc edema resolve slowly over 2– 10 months. Optic atrophy occurs in 20% of cases, but the visual prognosis often depends mostly upon the degree of accompanying diabetic retinopathy. In rare cases, diabetic papillopathy progresses to AION, with residual pallor and nerve fiber bundle defects. The pathophysiology is unclear but suspected to be mild, reversible ischemia. Therefore, the distinction of diabetic papillopathy as an entity unique from AION remains controversial and may represent a spectrum. There is no proven therapy for this disorder. Diabetes mellitus is discussed in BCSC Section 1, Update on General Medicine; associated ocular disorders are discussed in BCSC Section 12, Retina and Vitreous.
Bayraktar Z, Alacali N, Bayraktar S. Diabetic papillopathy in type II diabetic patients. Retina. 2002;22(6):752–758.
Regillo CD, Brown GC, Savino PJ, et al. Diabetic papillopathy. Patient characteristics and fundus findings. Arch Ophthalmol. 1995;113(7):889–895.
Papillophlebitis
Lonn and Hoyt originally named the syndrome of unilateral retinal venous congestion and optic disc edema in otherwise healthy, young patients as papillophlebitis. Other monikers include optic disc vasculitis and benign retinal vasculitis. The syndrome represents a subset of CRVO in the young, with unusually prominent disc edema.
The disorder typically presents with vague blurring of vision or even transient visual obscurations. Visual acuity is typically normal or mildly diminished. The pupils and color vision are normal, and visual field testing shows blind spot enlargement. Fundus examination shows marked retinal venous engorgement associated with hyperemic optic disc edema (Fig 4-11). Retinal hemorrhages extending to the equatorial region are common. Fluorescein angiographic studies typically show retinal venous staining and leakage associated with circulatory slowing, without the regions of capillary occlusion observed in ischemic CRVO. A workup for hypercoagulable disorders can be considered for patients with papillophlebitis. The condition usually resolves spontaneously over 6–12 months, with either no vision loss or only mild impairment related to incompletely resolved maculopathy. For further discussion, see BCSC Section 12, Retina and Vitreous.
Figure 4-11 Papillophlebitis. Optic disc edema in a 28-year-old woman with engorgement and tortuosity of retinal venous
system. Visual acuity is 20/30. (Reprinted from Kline LB, Foroozan R, eds. Optic Nerve Disorders. 2nd ed. Ophthalmology Monograph 10. New York: Oxford University Press, in cooperation with the American Academy of Ophthalmology; 2007:218.)
Anterior orbital compressive or infiltrative lesions
Most orbital compressive lesions do not produce optic disc edema, but anterior orbital masses may compress the anterior intraorbital optic nerve and its venous drainage, producing disc edema. These anterior lesions are sometimes associated with optociliary shunt vessels (retinochoroidal collaterals) and occasionally lead to CRVO. Compressive lesions or enlarged extraocular muscles (in thyroid eye disease) at the orbital apex that spare the exiting retinal venous system may or may not result in disc edema but can produce optic nerve dysfunction and eventual atrophy. In all other respects, the clinical syndrome is the same as for other intraorbital and intracanalicular compressive lesions.
Similarly, infiltration (through inflammatory, infectious, or neoplastic mechanisms) of the optic nerve most often is a retrobulbar process, but anterior involvement may present with optic disc edema. The optic disc may simply be edematous or display features of superimposed cellular