Neil R. Miller

A Randomized, Controlled Trial of Corticosteroids in the Treatment of Acute Optic Neuritis

Background and Methods. The use of corticosteroids to treat optic neuritis is controversial. At 15 clinical centers, we randomly assigned 457 patients with acute optic neuritis to receive oral prednisone (1 mg per kilogram of body weight per day) for 14 days; intravenous methylprednisolone (1 g per day) for 3 days, followed by oral prednisone (1 mg per kilogram per day) for 11 days; or oral placebo for 14 days. Visual function was assessed over a six-month follow-up period. Results. Visual function recovered faster in the group receiving intravenous methylprednisolone than in the placebo group; this was particularly true for the reversal of visual-field defects (P = 0.0001). Although the differences between the groups decreased with time, at six months the group that received intravenous methylprednisolone still had slightly better visual fields (P = 0.054), contrast sensitivity (P = 0.026), and color vision (P = 0.033) but not better visual acuity (P = 0.66). The outcome in the oral-prednisone group did ...

Multiple sclerosis risk after optic neuritis: Final optic neuritis treatment trial follow-up

OBJECTIVE To assess the risk of developing multiple sclerosis (MS) after optic neuritis and the factors predictive of high and low risk. DESIGN Subjects in the Optic Neuritis Treatment Trial, who were enrolled between July 1, 1988, and June 30, 1991, were followed up prospectively for 15 years, with the final examination in 2006. SETTING Neurologic and ophthalmologic examinations at 13 clinical sites. PARTICIPANTS Three hundred eighty-nine subjects with acute optic neuritis. MAIN OUTCOME MEASURES Development of MS and neurologic disability assessment. RESULTS The cumulative probability of developing MS by 15 years after onset of optic neuritis was 50% (95% confidence interval, 44%-56%) and strongly related to presence of lesions on a baseline non-contrast-enhanced magnetic resonance imaging (MRI) of the brain. Twenty-five percent of patients with no lesions on baseline brain MRI developed MS during follow-up compared with 72% of patients with 1 or more lesions. After 10 years, the risk of developing MS was very low for patients without baseline lesions but remained substantial for those with lesions. Among patients without lesions on MRI, baseline factors associated with a substantially lower risk for MS included male sex, optic disc swelling, and certain atypical features of optic neuritis. CONCLUSIONS The presence of brain MRI abnormalities at the time of an optic neuritis attack is a strong predictor of the 15-year risk of MS. In the absence of MRI-detected lesions, male sex, optic disc swelling, and atypical clinical features of optic neuritis are associated with a low likelihood of developing MS. This natural history information is important when considering prophylactic treatment for MS at the time of a first acute onset of optic neuritis.

Vigabatrin-associated retinal cone system dysfunction Electroretinogram and ophthalmologic findings

Objective: To determine the sources of vigabatrin-associated visual disturbances in patients treated for epilepsy. Background: Vigabatrin is an extremely effective antiepileptic drug that selectively increases brain gamma-aminobutyric acid (GABA). Several patients recently developed constricted visual fields during vigabatrin treatment in the United Kingdom, indicating the possibility of GABA-associated retinal dysfunction. Methods: Patients with visual symptoms treated chronically with vigabatrin at our center underwent visual evoked potentials (VEP), electroretinograms (ERG), and visual field and ophthalmologic examinations. Results: Four of 38 patients treated with vigabatrin developed visual symptoms 2 to 40 months after starting the drug. Two patients complained of constricted visual fields and two had blurred vision. ERG demonstrated evidence of bilateral retinal dysfunction consistent with reduced inner retinal cone response in all four patients. Oscillatory potential responses were lost, suggesting impairment of the highly GABAergic amacrine cells. Two of the patients had normal VEPs and minimal findings on clinical ophthalmology examinations despite abnormal ERGs. Abnormal examination findings were narrowed retinal arteries, surface wrinkling retinopathy, and abnormal macular reflexes. One patient also had reduced rod photoreceptor function in the more symptomatic left eye. Conclusions: Visual field constriction and blurring during vigabatrin therapy is associated with retinal cone system dysfunction. Visual symptoms may represent selective vulnerability of retinas of affected patients to GABAergic effects of vigabatrin. The prevalence and course of retinal changes associated with vigabatrin therapy are important to determine in a larger group of patients.

Intraobserver and Interobserver Agreement in Measurement of Optic Disc Characteristics

Reliable measures of optic nerve status are important parameters for epidemiologic and clinical studies of glaucoma. Stereo fundus photography has been used to reduce interobserver variation, but little data have been reported quantifying the level of agreement in these situations. This article examines chance-corrected intraobserver and interobserver agreement for horizontal and vertical cup:disc ratios and width of the narrowest remaining neuroretinal rim on stereo, color, fundus photographs. Intraobserver agreement was substantial to almost perfect for both readers (kappas between 0.82 and 0.86 for horizontal and vertical cup:disc ratios and 0.71 for the neuroretinal rim). Interobserver agreement was also substantial (kappas of 0.71 for horizontal cup:disc ratio, 0.74 for vertical cup:disc ratio, and 0.58 for the neuroretinal rim). Both intraobserver and interobserver agreement were best for glaucoma patients followed by ocular hypertensives and controls. Dichotimizing cup:disc ratios into suspicious or not suspicious using a range of cutoff points (greater than or equal to 0.5, greater than or equal to 0.6, and greater than or equal to 0.7 disc diameters [DD]) had little effect on agreement levels. Estimation of the status of the optic nerve is complex, requiring judgment about the shape and structure of the cup. Agreement is optimized by using stereo photographs, using the same observer and, when evaluating progression, comparing photographs from different points in time at a single sitting.

Lumboperitoneal shunt for the treatment of pseudotumor cerebri

We conducted a retrospective study of 27 patients with pseudotumor cerebri (PTC) treated with at least one lumboperitoneal shunt (LPS) to ascertain the efficacy of this treatment.The average duration of follow-up for this population was 77 months (median, 47 months), with a range of 21 to 278 months. A functioning LPS was successful in alleviating symptoms in all patients studied, and no patient with a functioning shunt complained of shunt-related symptoms, such as low-pressure headache or abdominal pain, within 2 months after the shunt was performed. Twelve patients (44%) required no revisions. The number of revisions among the 15 patients (56%) who required them ranged from 1 (5 patients) to 13 (1 patient). Three of these patients required 35 of the 66 total shunt revisions (53%). There were no major complications from LPS, other than failure of the shunt, even in patients who required multiple shunts. We conclude that placement of a lumboperitoneal shunt is satisfactory treatment for the majority of patients with PTC who require surgical therapy for the disorder, even though some patients ultimately require multiple shunt revisions. NEUROLOGY 1996;46: 1524-1530

Clinical spectrum of posterior ischemic optic neuropathy

PURPOSE To describe the systemic and visual characteristics and prognosis in patients with posterior ischemic optic neuropathy (PION). DESIGN Observational case series. METHODS Retrospective chart review in a multicenter setting. Seventy-two patients (98 eyes) with a clinical diagnosis of PION. Co-morbid systemic diseases and visual function were recorded at both initial presentation and after mean visual follow-up of 4.1 years and systemic follow-up of 5.4 years. RESULTS PION occurred in three main settings: in the perioperative period following a variety of surgical procedures (28 patients), associated with giant cell (temporal) arteritis (6 patients), and associated with nonarteritic systemic vascular disease (38 patients). Patients with perioperative and arteritic PION were more likely to have severe, bilateral visual loss that did not improve. Among eyes with nonarteritic PION, 34% experienced improvement in vision, 28% remained stable, and 38% worsened. Among patients with nonarteritic PION, carotid artery disease and a history of stroke (with or without carotid artery disease) were both associated with a statistically significant increased risk of poor final visual outcome. CONCLUSIONS There are three distinct subtypes of PION: perioperative, arteritic, and nonarteritic. Patients with PION that is unassociated with surgery should undergo an evaluation for systemic vascular diseases, including giant cell arteritis, that may or may not be apparent at the time of vision loss. The visual prognosis for patients with perioperative or arteritic PION is poor, whereas that for nonarteritic PION is similar to that for patients with nonarteritic AION.

Efficacy of unilateral versus bilateral temporal artery biopsies for the diagnosis of giant cell arteritis.

PURPOSE To determine the utility of unilateral versus bilateral temporal artery biopsies in detecting the pathologic changes of giant cell arteritis. METHODS We performed a retrospective study to determine the utility of unilateral versus bilateral temporal artery biopsies in detecting the pathologic changes of giant cell arteritis. The pathologic reports of consecutive temporal artery biopsy specimens received at the Wilmer Ocular Pathology Laboratory over a 28-year period from 1968 to 1996 were reviewed. RESULTS Of 908 specimens examined from 758 patients, 300 specimens were simultaneous bilateral biopsies from 150 patients, 72 specimens were bilateral sequential biopsies from 36 patients, and the remaining 536 specimens were unilateral biopsies from 536 patients. Of the 186 patients who had bilateral simultaneous or nonsimultaneous biopsies, 176 had identical diagnoses on both sides. In four patients, no artery was obtained on one side. In each of the remaining six patients, five of whom had bilateral simultaneous biopsies and one of whom had bilateral sequential biopsies performed 8 days apart, the biopsy specimen from one side was interpreted as showing only arteriosclerotic changes with no evidence of active or healed arteritis, whereas the other specimen was interpreted as showing either probable healed arteritis (three specimens) or possible early arteritis (three cases). In none of the six patients with differing diagnoses between the two sides was one side interpreted as showing definite, active giant cell arteritis. Five of the six patients were subsequently determined to have giant cell arteritis, based on a combination of clinical findings, erythrocyte sedimentation rate, and response to treatment with systemic corticosteroids. CONCLUSIONS The results of this study indicate that performing a bilateral simultaneous or sequential temporal artery biopsy improves the diagnostic yield in at least 3% of cases of giant cell arteritis, whereas in 97% of cases, the two specimens show the same findings. Thus, in patients in whom only one artery can be biopsied, there is a high probability of obtaining the correct diagnosis. Nevertheless, although the improvement in diagnostic yield of bilateral temporal artery biopsies is low, the consequences of both delayed diagnosis and treatment of giant cell arteritis as well as the use of systemic corticosteroids in patients who do not have giant cell arteritis are of such potential severity that consideration should always be given to performing bilateral temporal artery biopsies in patients suspected of having the disease.

The Incidence of Vision Loss due to Perioperative Ischemic Optic Neuropathy Associated With Spine Surgery : The Johns Hopkins Hospital Experience

Study Design. Twenty-year retrospective review of 14,102 spine surgeries. Objective. To determine the incidence of perioperative ischemic optic neuropathy (POION) in spine surgery at our institution. Summary of Background Data. In recent years, perioperative vision loss in patients undergoing spine surgery has become an issue of increasing concern to physicians, patients, and medicolegal experts. The incidence of POION in spine surgery has been addressed in two separate studies that found incidences of 0% and 0.12%. Methods. We performed a 20-year database search for all patients who underwent spine surgery and had a concurrent ICD-9 discharge diagnosis pertaining to vision loss. Patient charts were reviewed in detail to confirm the diagnosis of POION. Results. Of 14,102 cases of spine surgery during the study time frame, we identified 4 cases of POION, for an incidence of 0.028%. In 3 of the 4 cases, surgery was performed with the patient in the prone position; the fourth patient was placed in the lateral decubitus position. All affected patients had experienced intraoperative anemia, hypotension, or both. The average time of surgery was 420 minutes. Conclusions. POION is a rare but potentially devastating and untreatable complication of spine surgery, particularly that performed with the patient in the prone position. Anemia, hypotension, long duration of surgery, and significant intraoperative hydration may all be risk factors for this condition. All patients undergoing spine surgery should be informed about the low but definite risk of this condition, and every attempt should be made during surgery to maintain stable hemoglobin and mean arterial pressure and to avoid overhydration.

Solitary oculomotor nerve palsy in childhood.

In most cases of isolated oculomotor nerve palsy in 30 patients under age 20 years the palsy was congenital, and aberrant regeneration was present. The most common causes of acquired oculomotor nerve palsy were blunt trauma and infectious processes, both local and systemic. Neoplasms, aneurysms, and ophthalmoplegic migraine caused the other cases. The causes of isolated oculomotor nerve palsy in childhood differ from those in adults both in nature and in frequency of occurrence.

blindness after Reduction of Facial Fractures

&NA; Blindness in patients suffering maxillofacial trauma is usually caused by optic nerve or optic canal injuries. It is, however, an uncommon complication of facial trauma, with a reported incidence of only 2 to 5 percent.1–6 Blindness may also follow surgical repair of facial fractures. Many mechanisms, such as intraoperative direct nerve injury,7 retinal arteriolar occlusion associated with orbital edema,8–11 or delayed presentation of indirect optic nerve injury sustained at the time of the initial trauma,12 have been implicated in causing this blindness. In this article, four cases of visual loss after surgical repair of facial trauma are reported. In a review of the University of Maryland Shock Trauma experience with facial trauma over 11 years, we discovered that 2987 of the 29,474 admitted patients (10.1 percent) sustained facial fractures, and that 1338 of these fractures (44.8 percent) involved one or both of the orbits. One thousand two hundred forty of these patients underwent operative repair of their facial fractures. Three patients experienced postoperative complications that resulted in blindness, a total incidence of only 0.242 percent. Postoperative ophthalmic complications seem to be primarily mediated by indirect injury to the optic nerve and its surrounding structures. The most frequent cause of postoperative visual loss is an increase in intraorbital pressure in the optic canal. When our data were added to the summarized cases, blindness was attributable to intraorbital hemorrhage in 13 of 27 cases (48 percent). In addition, 5 cases in our review attribute the visual loss to unspecified mechanisms of increased intraorbital pressure, bringing the total cases of visual loss caused by intraorbital pressure or hemorrhage to 18 of 27 cases, or 67 percent. Within the restricted confines of the optic canal, even small changes in pressure potentially may cause ischemic optic nerve injury. (Plast. Reconstr. Surg. 102: 1821, 1998.)