Sophia M. Chung

Nonarteritic Ischemic Optic Neuropathy: The Impact of Tobacco Use

BACKGROUND Numerous associations to anatomic variation and systemic vascular disease have been made to anterior ischemic optic neuropathy (AION) but exogenous agents have not been emphasized. The authors studied the effect that smoking had in the development of AION. The relevance of other intraocular and systemic vascular disease to AION also is discussed. METHODS Over a 10-year period (January 1980-May 1990), nonarteritic AION was diagnosed in 148 patients, 137 of whom were included in this analysis. FINDINGS Of the 137 patients identified with nonarteritic AION, 28 smokers were statistically younger, at 51 years of age, compared with 83 nonsmokers whose mean age was 64 years (P = 0.005). CONCLUSIONS Cigarette smoking is an important risk factor in the development of AION. Cessation of smoking appears to reduce the risk of AION to that of the nonsmoking population.

Safety issues in magnetic resonance imaging.

Although generally considered safe, magnetic resonance imaging (MRI) has a number of safety issues, including the effects of high magnetic fields and radiofrequency pulses on the body, and on implanted devices, the side effects of contrast agents, toxicity during pregnancy, claustrophobia, and hearing loss.

Evidence of Optic Pathway Gliomas after Previously Negative Neurolmaging

PURPOSE The authors emphasize the potential for the development of anterior visual pathway gliomas, evidenced by computed tomography (CT) or magnetic resonance imaging (MRI) scans, in neurofibromatosis type 1 (NF1) patients who previously had normal neuroimaging studies. METHODS The clinic charts and CT and MRI scans were retrospectively reviewed for all patients evaluated at the neurofibromatosis clinic of one referral center over a period of 7 years. Patients with neuroimaging studies demonstrating anterior visual pathway gliomas who previously had normal scans were identified, and their cases are described in detail. A similar, previously reported series, from the pediatric literature, was also reviewed. RESULTS Eight percent (28/360) of patients had CT or MRI scans revealing optic gliomas. Two of these patients had normal neuroimaging studies previously. CONCLUSION A negative neuroimaging study in an NF1 patient does not exclude the future development of an optic glioma.

Visual Outcome in Bilateral Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of visual loss in the older population. Bilateral NAION is a well-documented entity; however, no study to date has compared the visual outcome between affected eyes. METHODS The authors retrospectively reviewed the charts of 99 patients with diagnoses of NAION over 3 1/2 years. In the 23 patients with bilateral involvement, 16 were included in the study for analysis of final visual outcome between affected eyes. Snellen acuity, Ishihara color plates, and Humphrey automated perimetry were evaluated as the parameters of visual function. Descriptive analysis of the outcome between affected eyes for each parameter is presented as a frequency distribution of pre-defined groups. Statistical significance is established using nonparametric tests. RESULTS Bilateral NAION was found in 23% (23/99) of the patients studied. The authors identified a high percent agreement between eyes with regard to visual acuity (81% within 3 Snellen lines), color vision (69% within 3 plates), and Humphrey visual field (75% within 5 decibels of mean deviation). Additionally, there was a statistically significant correlation between affected eyes for all three visual parameters: visual acuity (P = 0.043), color vision (P = 0.001), and Humphrey visual field (P = 0.039). CONCLUSION The authors found a high percent agreement and statistically significant correlation in final outcome between affected eyes of patients with bilateral NAION for visual acuity, color vision, and visual field loss. With a larger series, it may be possible to predict the visual outcome of the second affected eye based on the parameters of the first eye.

Ocular neuromyotonia: differential diagnosis and treatment

Abstract Ocular neuromyotonia (ONM) is a rare but distinctive clinical entity characterized by involuntary episodic contraction of one or more muscles supplied by the ocular motor nerves. A retrospective review was conducted on all patients with ONM seen by the neuroophthalmology service in the past 20 years. Ten patients were identified with ONM; six affecting vertical muscles (superior oblique; inferior rectus; superior rectus) and four affecting lateral rectus muscles. Case 1 has been reported previously. Most episodes occurred every 10–40 min, lasted a few seconds to several minutes, and were repeated throughout the day. Only two patients had previously undergone cranial radiation. Two had thyroid eye disease. One patient presented with superior oblique myokymia and subsequently developed ONM. Membrane stabilizing medications were prescribed in 7 of the 10 patients with varied success. ONM episodes ceased after extraocular muscle surgery in one patient with thyroid eye disease.

Optic neuropathy, headache, and diplopia with MRI suggestive of cerebral arteritis in relapsing polychondritis.

The pathogenesis of central nervous system disease in relapsing polychondritis (RPC) is unknown but may be related to cerebral arteritis. Previous reports have described clinical and histopathologic evidence of cerebral vasculitis in RPC; however, a neuroimaging correlate has not been reported. We present a 36-year-old man with neuro-ophthalmic features of RPC whose magnetic resonance imaging revealed multifocal gray- and white-matter high intensities. This pattern is consistent with cerebral arteritis as described in other systemic vasculitides.

Retinal, ophthalmic, or ocular migraine

Ocular migraine, an uncommon cause of transient monocular visual loss, is an entity physicians should be able to recognize in order to provide appropriate treatment and to avoid unnecessary testing. The following text provides an overview of ocular migraine, including discussion of accepted terminology, clinical presentation, and pathophysiology. An ocular and systemic differential diagnosis, appropriate evaluation, therapy, and prognosis are also discussed.

Binocular Problems in Bitemporal Hemianopsia

One of the prerequisites for comfortable binocular single vision (BSV) is the presence of normal overlapping visual fields. Any defect in the visual field of one or both eyes may interfere with BSV...

Acquired Nonparalytic Causes of Superior Oblique Dysfunction

Background and Purpose To conduct a retrospective study to investigate the causes of acquired superior oblique dysfunction, excluding paralysis, in a consecutive series of adult patients and to compare presenting symptoms and clinical findings. Methods A retrospective review of all adult patients with superior oblique dysfunction between the ages of 18 and 80 who met the study profile was conducted at Saint Louis University Medical Center between January 2000 and April 2012. The presenting symptoms, clinical findings, and treatment course for each patient was recorded. The study was approved by the Institutional Review Board of our institution. Results Acquired forms of nonparalytic superior oblique dysfunction were identified in forty-eight patients. These included superior oblique myokymia (twenty-three patients), superior oblique click syndrome or variable Brown syndrome (nine), canine tooth syndrome (five), spontaneous acquired Brown syndrome (four), iatrogenic or traumatic Brown syndrome (four), and ocular neuromyotonia affecting the superior oblique (three). Conclusions Several nonparalytic entities were identified that caused superior oblique dysfunction. Clinical findings may be similar despite entirely different mechanisms. Subjective symptoms may be difficult for the patient to describe or for the examiner to elicit on the day of the examination. Specific techniques can be used in eliciting, differentiating, and documenting the conditions. These included trochlear palpation, modified head tilt technique, interpretation of torsion, and Hess charts.

Neurointervention in Ophthalmologic Disorders

It is not uncommon for the ophthalmologist to be the first to diagnose neurological pathology. Some of these conditions will be amenable to catheter-based neurointervention. Among these conditions, cerebral aneurysms and carotid-cavernous fistulas are the two most common conditions. Idiopathic intracranial hypertension is another disease that may be amenable to neurointerventional treatment, although its role remains controversial. Cerebral aneurysms have been described in previous chapters (see Chaps. 10 and 11) and only the ophthalmologic manifestations are described here. The remainder of the chapter will focus on the anatomy, clinical presentation, imaging characteristics, and management of the carotid-cavernous fistula and idiopathic intracranial hypertension.