Visual fields at follow-up in the Ischemic Optic Neuropathy Decompression Trial: evaluation of change in pattern defect and severity over time.

PURPOSE: To evaluate change from baseline to 12 months follow-up in study and nonstudy (fellow) eye visual fields from the Ischemic Optic Neuropathy Decompression Trial (IONDT). DESIGN: Randomized controlled trial and observational study. PARTICIPANTS: The IONDT enrolled patients >or=50 years with acute nonarteritic ischemic optic neuropathy (NAION). Randomized patients (n = 258) had visual acuity 20/64 or refused randomization. INTERVENTIONS: Optic nerve decompression surgery (n = 127) or careful follow-up (n = 131). MAIN OUTCOME MEASURES: We measured visual fields at baseline and at 6 and 12 months follow-up. Using a computerized system, we classified visual field defects by pattern, location, and severity. We examined changes over time by treatment group, age, baseline comorbidities, and change in visual acuity. In fellow (nonstudy) eyes, we assessed change by whether NAION was present at baseline and also incidence of NAION by whether a visual field defect was present at baseline. RESULTS: We analyzed 245 study eye visual field pairs (179 and 66, randomized and nonrandomized, respectively) for change from baseline to 12 months. We observed significant changes in defect distribution within the central field (P = 0.02) for randomized eyes. Superior and inferior altitudinal defects were less severe at follow-up in both randomized and nonrandomized eyes. We observed an association between change in central field severity and change in visual acuity from baseline (P<0.001 at 6 months; P = 0.01 at 12 months; Kendall's tau-b), but no association between visual field change and treatment group, age, or baseline comorbidities. Superior and inferior visual field defects present at baseline in nonstudy eyes improved at follow-up. Fellow (nonstudy) eyes with normal fields did not have an increased risk of developing NAION compared with eyes with >or=1 defects. CONCLUSIONS: Visual fields of NAION patients enrolled in the IONDT were relatively stable from baseline to follow-up. A visual field defect in the nonstudy eye at baseline was not associated with development of NAION during follow-up compared with eyes with normal fields.

Neuron stress and loss following rodent anterior ischemic optic neuropathy in double-reporter transgenic mice.

PURPOSE: Nonarteritic anterior ischemic optic neuropathy (NAION) is an optic nerve infarct involving axons of retinal ganglion cell (RGC) neurons. The rodent NAION model (rAION) can use transgenic mouse strains to reveal unique characteristics about the effects of sudden optic nerve ischemia on RGCs and their axons. The impact of rAION on RGC stress patterns, RGC loss, and their axons after axonal infarct were evaluated. METHODS: A double-transgenic mouse strain was used, containing a construct with cyan fluorescent protein (CFP) under Thy-1 promoter control, and a construct with beta-galactosidase (lacZ) linked to the stress gene c-fos promoter. Thy-1 in the retina is expressed predominantly in RGCs, enabling stereologic analysis of CFP(+) RGC numbers and loss post-rAION-using confocal microscopy. RGC loss was correlated with axonal counts using transmission electron microscopy (TEM). LacZ immunohistochemistry was used to evaluate retinal cell stress after rAION. RESULTS: The 45,000 CFP(+) cells in the RGC layer of control animals compared with previous RGC quantitative estimates. rAION produced RGC stress, defined as lacZ expression, in patterns corresponding with later RGC loss. rAION-associated RGC loss correlated with regional nerve fiber layer loss. Axonal loss correlates with stereologically determined RGC loss estimates in transgenic mice retinas. CONCLUSIONS: Post-ON infarct RGC stress patterns correlate with regional RGC loss. Cellular lacZ levels in most RGCs are low, suggesting rAION-affected RGCs express c-fos only transiently. CFP(+) cell loss correlates closely with quantitative axonal loss, suggesting that the Thy-1 (CFP) transgenic mouse strain is appropriate for RGC stereologic analyses.

Development and validation of a computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial.

BACKGROUND: The objective of this report is to describe the methods used to develop and validate a computerized system to analyze Humphrey visual fields obtained from patients with non-arteritic anterior ischemic optic neuropathy (NAION) and enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT). The IONDT was a multicenter study that included randomized and non-randomized patients with newly diagnosed NAION in the study eye. At baseline, randomized eyes had visual acuity of 20/64 or worse and non-randomized eyes had visual acuity of better than 20/64 or were associated with patients refusing randomization. Visual fields were measured before treatment using the Humphrey Field Analyzer with the 24-2 program, foveal threshold, and size III stimulus. METHODS: We used visual fields from 189 non-IONDT eyes with NAION to develop the computerized classification system. Six neuro-ophthalmologists ("expert panel") described definitions for visual field patterns defects using 19 visual fields representing a range of pattern defect types. The expert panel then used 120 visual fields, classified using these definitions, to refine the rules, generating revised definitions for 13 visual field pattern defects and 3 levels of severity. These definitions were incorporated into a rule-based computerized classification system run on Excel(R) software. The computerized classification system was used to categorize visual field defects for an additional 95 NAION visual fields, and the expert panel was asked to independently classify the new fields and subsequently whether they agreed with the computer classification. To account for test variability over time, we derived an adjustment factor from the pooled short term fluctuation. We examined change in defects with and without adjustment in visual fields of study participants who demonstrated a visual acuity decrease within 30 days of NAION onset (progressive NAION). RESULTS: Despite an agreed upon set of rules, there was not good agreement among the expert panel when their independent visual classifications were compared. A majority did concur with the computer classification for 91 of 95 visual fields. Remaining classification discrepancies could not be resolved without modifying existing definitions. Without using the adjustment factor, visual fields of 63.6% (14/22) patients with progressive NAION and no central defect, and all (7/7) patients with a paracentral defect, worsened within 30 days of NAION onset. After applying the adjustment factor, the visual fields of the same patients with no initial central defect and 5/7 of the patients with a paracentral defect were seen to worsen. CONCLUSION: The IONDT developed a rule-based computerized system that consistently defines pattern and severity of visual fields of NAION patients for use in a research setting.

Functional and cellular responses in a novel rodent model of anterior ischemic optic neuropathy.

PURPOSE: Anterior ischemic optic neuropathy (AION) is caused by sudden loss of vascular supply to retinal ganglion cell (RGC) axons in the anterior portion of the optic nerve and is a major cause of optic nerve dysfunction. There has been no easily obtainable animal model of this disorder. The current study was conducted to design a novel model of rodent AION (rAION), to enable more detailed study of this disease. METHODS: A novel rodent photoembolic stroke model was developed that is directly analogous to human AION. Using histologic, electrophysiological, molecular- and cell biological methods, the early changes associated with isolated RGC axonal ischemia were characterized. RESULTS: Functional (electrophysiological) changes occurred in RGCs within 1 day after rAION, with a loss of visual evoked potential (VEP) amplitude that persisted in the long term. The retinal gene expression pattern rapidly changed after rAION induction, with an early (<1 day) initial induction of c-Fos mRNA, and loss of RGC-specific gene expression. RGC-specific protein expression declined 2 days after detectable mRNA level changes, and immunostaining suggested that multiple retinal layers react to isolated RGC axonal ischemia. CONCLUSIONS: rAION rapidly results in electrophysiological and histologic changes similar to clinical AION, with reactive responses in primary and supporting neuronal cell layers. The rAION model can enable a detailed analysis of the individual retinal and optic nerve changes that occur after optic nerve stroke, which may be useful in determining possible therapeutic interventions for this disorder.

In vivo assessment of the window of barrier opening after osmotic blood-brain barrier disruption in humans.

OBJECT: Osmotic blood-brain barrier (BBB) disruption induced by intraarterial infusion of mannitol is used in conjunction with chemotherapy to treat human brain tumors. The time course to barrier closure, or the so-called therapeutic window, has been examined in animals but little information is available in humans. The authors, therefore assessed the time course to barrier closure after osmotic BBB disruption in humans. METHODS: Disruption of the BBB was demonstrated using 99mTc-glucoheptonate (TcGH) single-photon emission computerized tomography (SPECT) scanning in 12 patients who were treated monthly with combination chemotherapy in conjunction with BBB disruption. The primary diagnosis was primary central nervous system lymphoma in seven patients and primitive neuroectodermal tumors in five. The TcGH (20 mCi) was injected at 1- to 480-minute intervals after osmotic BBB disruption, and patients underwent SPECT scanning after 4 hours. A total of 38 studies was performed. Good-to-excellent BBB disruption was obtained in 29 procedures and poor-to-moderate disruption was seen in the other nine studies. The TcGH indices correlated with the degree of BBB disruption as measured postprocedure on contrast-enhanced CT scans (r = 0.852). Mean baseline TcGH indices were 1.02+/-0.07. For the group of patients with good-to-excellent disruptions the mean indices at 1 minute postdisruption measured 2.19+/-0.18. After 40 minutes no significant change was noted (mean index 2.13+/-0.2). Then the indices declined more steeply and at 120 minutes after the disruption the index was 1.36+/-0.02. A very slow decline was noted between 120 and 240 minutes after mannitol infusion. At 240 minutes the barrier was still open for all good-to-excellent disruptions (index 1.33+/-0.08) but at 480 minutes the mean indices had returned to the baseline level. CONCLUSIONS: Results of these in vivo human studies indicate that the time course to closure of the disrupted BBB for low-molecular-weight complexes is longer than previously estimated. The barrier is widely open during the first 40 minutes after osmotic BBB disruption and returns to baseline levels only after 6 to 8 hours following the induction of good or excellent disruption. These findings have important clinical implications for the design of therapeutic protocols.

Comprehension of temporal terms by good and poor readers.

Poor beginning readers often have difficulty comprehending spoken sentences with complex syntactic structures. This study attempts to identify the reasons for this difficulty. Second-grade good and poor readers were tested for comprehension of spoken sentences containing the temporal terms before and after. Processing load was varied systematically while holding syntax constant in an effort to determine whether processing factors contribute to poor readers' comprehension problems, or whether poor readers are simply lacking the structural knowledge required to understand sentences containing temporal terms. The poor readers' high level of performance under conditions of reduced processing demands suggests that their misinterpretations in spoken language understanding may be due, in large part, to limitations in verbal working memory.

Pulse-synchronous tinnitus and sigmoid sinus wall anomalies: descriptive epidemiology and the idiopathic intracranial hypertension patient population.

OBJECTIVE: Describe the clinical features of a population of patients with sinus wall anomalies (SWA) and pulse-synchronous tinnitus (PST). STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: Patients with PST and SWA undergoing surgical management between 2007 and 2012. INTERVENTION: Transmastoid sinus wall reconstruction. MAIN OUTCOME MEASURE: Age, sex, BMI, and postoperative course. Two-tailed t tests (p ≤ 0.05) compared BMI and age of the study group with negative and positive controls. RESULTS: Thirteen patients presented with sigmoid sinus diverticulum (39.4%) and 20 (60.6%) with sinus wall dehiscence. Thirty ears were successfully treated with surgery (responders), and 3 were not (nonresponders). Responders' mean age was 38 years, with 26 female patients (92.9%) and 2 male (7.1%). BMI of responders compared with nonresponders did not differ significantly (35.5 versus 33.4 kg/m2, p = 0.08). BMI of responders was elevated compared with an asymptomatic control group (35.5 versus 27.4 kg/m2, p < 0.0001). BMI of responders did not differ significantly compared with a cohort of patients with spontaneous CSF otorrhea and temporal bone encephaloceles (35.5 versus 40.7 kg/m2, p = 0.17). CONCLUSION: The patients in this study had elevated BMI and were more likely to be female. This patient population strongly resembles that of patients with IIH, suggesting the possibility that SWA may be a cause of PST in some patients with IIH. Illustrative cases supporting this hypothesis are presented.

Ocular neuroprotection by siRNA targeting caspase-2.

Retinal ganglion cell (RGC) loss after optic nerve damage is a hallmark of certain human ophthalmic diseases including ischemic optic neuropathy (ION) and glaucoma. In a rat model of optic nerve transection, in which 80% of RGCs are eliminated within 14 days, caspase-2 was found to be expressed and cleaved (activated) predominantly in RGC. Inhibition of caspase-2 expression by a chemically modified synthetic short interfering ribonucleic acid (siRNA) delivered by intravitreal administration significantly enhanced RGC survival over a period of at least 30 days. This exogenously delivered siRNA could be found in RGC and other types of retinal cells, persisted inside the retina for at least 1 month and mediated sequence-specific RNA interference without inducing an interferon response. Our results indicate that RGC apoptosis induced by optic nerve injury involves activation of caspase-2, and that synthetic siRNAs designed to inhibit expression of caspase-2 represent potential neuroprotective agents for intervention in human diseases involving RGC loss.

Intravitreal methotrexate for treating vitreoretinal lymphoma: 10 years of experience.

AIM: To describe our experience in treating vitreoretinal involvement of primary central nervous system lymphoma, by intravitreal injections of methotrexate (MTX). METHODS: Patients with suspected intraocular lymphoma underwent a diagnostic vitrectomy. Samples were sent for cytology, genetic evaluation and for interleukin level measurements. Treatment protocol included injection of 400 microg/0.1 ml MTX intravitreally twice weekly for 4 weeks, once weekly for 8 weeks, and then once monthly for 9 months, for a total of 25 injections. Data were collected from the patients' records and included, inter alia, response to intravitreal MTX measured by time to disappearance of vitreal cells and retinal infiltrates, changes in visual acuity, and clinical recurrence rate. RESULTS: In the past 10 years we have treated 44 eyes of 26 patients; seven patients had monocular involvement, and 19 binocular. Six patients were initially diagnosed as having a non-responsive uveitis, and 16 with either CNS or systemic lymphoma with later involvement of the eye. Four patients had systemic lymphoma; one of them was found to have CNS lymphoma after the ocular involvement. Three patients had T cell lymphoma, and the rest had B cell lymphoma. Clinical remission was reached after 6.4 (3.4) (2-16) injections of MTX (mean (SD) (range)), with 95% of the eyes needing 13 injections or less to be cleared of malignant cells. None of the patients had an intraocular recurrence. Among the side effects, the most common was corneal epitheliopathy, which usually appeared after the third injection and began to subside when the intervals between injections increased. CONCLUSIONS: Vitreoretinal involvement of lymphoma can be controlled effectively and without serious adverse reactions by intravitreal MTX injections. The treatment protocol described herein has resulted in no intraocular recurrence so far and has had bearable side effects. The accumulating clinical results bring us to propose the consideration of this protocol as a good first-line treatment option for intraocular lymphoma.

Maculopathy in patients with primary CNS lymphoma treated with chemotherapy in conjunction with blood-brain barrier disruption.

AIM: To determine the incidence and characteristics of maculopathy associated with blood-brain barrier disruption (BBBD) which is used in treating primary central nervous system lymphoma (PCNSL). METHODS: Files of all 56 patients with PCNSL, with or without intraocular lymphoma (IOL), treated at Hadassah University Hospital during the years 1997-2007 were reviewed. Data on 46 patients for whom we had documentation of ocular examination were studied. Those who were alive at the time of the data collection were invited for further evaluation of the presence or absence of maculopathy. The patients were divided into four groups according to treatment protocol. Group 1: systemic intravenous chemotherapy; Group 2: systemic intravenous chemotherapy and intravitreal methotrexate (MTX); Group 3: systemic intra-arterial (IA) chemotherapy and BBBD; Group 4: systemic IA chemotherapy, BBBD, and intravitreal MTX. RESULTS: Of the 23 patients of Groups 1 and 2 who were not treated by BBBD, none developed maculopathy. Of those 23 patients who were treated by BBBD, 12 of 17 (70.5%) in Group 3 and three of six (50%) in Group 4, for a total of 15 of 23 (65.2%) developed maculopathy. The maculopathy did not significantly affect visual acuity in any of them. CONCLUSIONS: BBBD may cause maculopathy in almost two-thirds of patients treated for PCNSL, without affecting significantly the visual acuity. Intravitreal injection of MTX, according to the protocol which we apply, is not associated with maculopathy.