Floyd A. Warren

Linezolid-associated toxic optic neuropathy: a report of 2 cases.

We describe 2 cases in which the prolonged use of linezolid to treat complicated methicillin-resistant Staphylococcus aureus infections was followed by acutely developed blurred vision and progressive loss of vision and color perception during the ensuing few weeks. Both patients received a diagnosis of toxic optic neuropathy, and linezolid therapy was stopped. The patients experienced an initial rapid partial improvement and a subsequent gradual, almost complete, recovery over many months.

The Management of Optic Nerve Sheath Meningiomas

Thirty-eight patients (39 eyes) with optic nerve sheath meningiomas were entered into a treatment plan and were followed up for at least three years. Eighteen eyes were simply observed because they had minimal functional deficit or the eye was blind. Radiation was used on six eyes with documented progressive visual loss that still had useful vision. Surgery was initially used in an attempt to remove optic nerve sheath meningiomas but was abandonded except in exceptional cases. Total surgical removal of the tumor was carried out in ten eyes with loss of vision and in which the meningioma was growing. Surgery for subtotal or complete removal of the tumor followed by radiation was carried out in five eyes exhibiting aggressive growth of the tumor. This treatment plan has helped us to treat patients with optic nerve sheath meningiomas in an orderly way.

Management of nontraumatic vascular shunts involving the cavernous sinus

The authors managed 38 consecutive cases of nontraumatic vascular shunts involving the cavernous sinus. Selective angiography demonstrated 12 carotid cavernous fistulas (CCFs) and 26 dural arteriovenous shunts (DAVSs). Visual disability occurred from glaucoma, venous retinopathy, optic neuropathy, or diplopia. Ten patients with slow-flow shunts and minimal dysfunction were treated medically to lower intraocular pressure (IOP) and/or instructed in manual compression of the internal carotid artery, ipsilateral to the lesion, using the contralateral hand. Percutaneous intraarterial embolization using detachable balloons, isobutylcyanoacrylate, or polyvinyl alcohol particles was successful in 16/18 DAVSs and 9/10 CCFs. The neuro-ophthalmic signs resolved in these 25 cases. Complications occurred in five patients. These included a transient hemiparesis, twelfth nerve palsy, unilateral nasal field loss, a pseudoaneurysm causing a third-nerve paresis, and temporary cavernous sinus thrombosis. Conservative therapy in mild cases and embolization in cases with visual disability or progressive signs are warranted.

Aspirin reduces the incidence of second eye NAION: a retrospective study.

The objective of this study was to determine if aspirin reduces the incidence of second eye involvement after nonarteritic anterior ischemic optic neuropathy (NAION) in one eye. Records were reviewed of 131 patients who sustained unilateral NAION. Of these, the 33 patients who sustained second eye NAION were compared to those followed for a minimum of 2 years without sustaining a second eye NAION (67). Thirty-one of the 131 patients were excluded because of inadequate follow-up. Except for diabetes (relative risk [RR] 1.43, p = 0.05), the incidence of second eye NAION was independent of gender, age, cup/disk, hypertension, anemia, and migraine. The degree of visual acuity or field dysfunction in the first eye correlated poorly with the acuity (r = 0.28) and field (r =0.33) loss in the second eye. Aspirin (65–1,300 mg) taken two or more times per week decreased the incidence (17.5% vs. 53.5%) and relative risk (RR = 0.44, p = 0.0002) of second eye AION regardless of the usual risk factors. Even after eliminating those patients who had bilateral disease when first referred, ASA still reduced the incidence of second eye involvement (35% vs. 13%, RR = 0.74, p = 0.01). Aspirin may be an effective means of reducing second eye NAION.

Unilateral swollen disc due to increased intracranial pressure

Truly unilateral papilledema is rare and poses a diagnostic problem. The authors have prospectively looked for patients with truly unilateral papilledema and found 15 patients, 10 of whom had idiopathic intracranial hypertension. Neuroimaging did not indicate a reason for the lack of swelling in the other nerve. The visual deficits and outcomes were similar to those of patients with bilateral papilledema. Although monocular papilledema is uncommon, a lumbar puncture with opening pressure measurement should be considered.

Maculopathy Caused by Intra-arterially Administered Cisplatin and Intravenously Administered Carmustine

Eight patients with malignant gliomas were monitored with clinical examinations to study the effects of the combination of intravenous administration of carmustine and infraophthalmic intra-arterial administration of cisplatin on retinal and optic nerve function. Three patients developed a severe macular retinal pigment abnormality in the eye ipsilateral to the intra-arterial infusion. Electrophysiologic studies disclosed no evidence of a generalized disturbance in the photoreceptors, middle retinal layers, or retinal pigment epithelium. In contrast to previous studies involving patients whose visual loss was caused by vaso-occlusive lesions in the retina and optic nerve, our study involved patients with clinically significant maculopathy, that was not vascular in origin and that developed after treatment with carmustine and cisplatin. We suggest that the deficit may result from a localized retinal pigment disturbance in the macula.

Clinical neuro-ophthalmic findings in familial dysautonomia.

Background To define the clinical neuro-ophthalmic abnormalities of patients with familial dysautonomia (FD). Methods Sixteen patients (32 eyes) with the clinical and molecular diagnoses of FD underwent thorough neuro-ophthalmic clinical evaluation. Results Visual acuity ranged from 0.05 to 1.0 decimal units and was reduced in 15 of 16 patients. Mild to moderate corneal opacities were found in most patients but were visually significant in only 2 eyes. Red-green color vision was impaired in almost all cases. Depression of the central visual fields was present on automated visual fields in all patients, even in those with normal visual acuity. Temporal optic nerve pallor was present in all cases and was associated with retinal nerve fiber layer loss in the papillomacular region. Various ocular motility abnormalities also were observed. Conclusion Patients with FD have a specific type of optic neuropathy with predominant loss of papillomacular nerve fibers, a pattern similar to other hereditary optic neuropathies caused by mutations either in nuclear or in mitochondrial DNA, affecting mitochondrial protein function. Defects of eye movements, particularly saccades, also appear to be a feature of patients with FD.

Growth of prolactinoma despite lowering of serum prolactin by bromocriptine.

Four patients with macroprolactinomas treated with bromocriptine had tumor growth and visual loss despite marked reduction in their serum prolactin levels. Explanations for this dissociation of tumor growth and prolactin measurement might include noncompliance. Patients treated with bromocriptine require periodic examination by computed tomographic scan or magnetic resonance imaging and neuro-ophthalmological evaluation in addition to monitoring of serum prolactin.

Venous obstruction as the cause of retinal/choroidal dysfunction associated with arteriovenous shunts in the cavernous sinus

Objective To determine the hemodynamlc abnormalities that result in visual acuity loss because of retinal or choroidal dysfunction associated with arteriovenous shunts (AVS) that involve the cavernous sinus. Methods Retrospective study of the records of 250 patients with either a carotid cavernous fistula or dural arteriovenous malformation revealed a total of 10 patients with vision loss secondary to retinopathy (group I) or choroidal effusion (group II). The cerebral angiograms of these 10 patients and 10 additional patients with visual dysfunction due to elevated intraocular pressure (group III) were evaluated to determine whether the three groups could be distinguished by a specific vasculopathic pattern. Particular attention was given to the extent of thrombosis in the ophthalmic venous system and cavernous sinus. Results There were angiographic signs of severe thrombosis in the ophthalmic vein in nine patients and in the cavernous sinus in seven patients ipsilateral to the retinal or choroidal lesion. In contrast, in group III, severe thrombosis in the ipsilateral ophthalmic vein and in the cavernous sinus occurred in one and two patients, respectively. Closure of the AVS improved the visual acuity in 1 of 4 patients in group I and in 4 of 5 patients in group II, and normalized the intraocular pressure in all patients. Conclusions Ophthalmic vein thrombosis, rather than arterialization of the venous system or an arterial “steal,” is the principal cause of retinal or choroidal dysfunction associated with AVS to the cavernous sinus. Following AVS closure, visual recovery is more frequent with choroidal effusion or detachment rather than with retinopathy.

Isolated lymphoma of the anterior visual pathway diagnosed by optic nerve biopsy.

A 72-year-old previously healthy man developed rapidly progressive visual loss, and brain imaging showed features suggestive of a malignant glioma of the anterior visual pathway. Biopsy of one optic nerve yielded a diagnosis of lymphoma. There was no evidence of an extracranial non-Hodgkin lymphoma, so the conclusion was that this represented a primary central nervous system lymphoma (PCNSL). PCNSL isolated to the optic chiasm has been described only once in an immunocompetent patient. Our patient is unusual in that the lymphoma involved the optic nerve, chiasm, and tract in an immunocompetent patient.