[Neurological involvement of sarcoidosis: current diagnostic and therapeutic strategies]. / Atteinte neurologique de la Sarcoïdose : stratégies diagnostiques et thérapeutiques actuelles.

Neurosarcoidosis (NS) is a rare but severe form of sarcoidosis. NS is associated with significant morbidity and mortality. Mortality is about 10% at 10 years with more than 30% of patients who have a significant disability. The most frequent features are cranial neuropathy (the facial and optic nerve most commonly affected), cranial parenchymal lesions, meningitis, spinal corn abnormalities (20-30%) and more rarely peripheral neuropathy (approximately 10-15%). The challenge of diagnosis is to eliminate other diagnoses. Atypical presentations should make to discuss the need for cerebral biopsy in order to highlight the presence of granulomatous lesions while eliminating alternative diagnosis. Therapeutic management is based on corticosteroid therapy and immunomodulators. There are no comparative prospective study to allow us to define the first-line immunosuppressive treatment and the therapeutic strategy in refractory patients. Conventional immunosuppressants such as methotrexate, mycophenolate mofetil and cyclophosphamide are commonly used. Data on the efficacy of anti-TNFα (including infliximab) in refractory and/or severe forms are increasing during the last ten years. Additional data is necessary to assess their interest in first line in patients with severe involvement and a significant risk of relapse.

Safe short circuit in cataract surgery: Incidence and risk factors for intraoperative medical action.

Cataract surgery has become the most frequent surgical procedure performed every year in Western countries. Perioperative patient circuit has to be adapted to the important medical needs and progress. Hence, a secure short circuit (SSC) for surgeries of the anterior segment of the eye under topical anaesthesia was created. Patients included in the circuit are selected first by surgeons and answer a medical questionnaire, they do not have any preoperative evaluation by anaesthesiologist, are monitored during surgery by the surgical team and in case of problem an intraoperative medical action (IMA) can be performed. We conducted a retrospective observational incidence study of the occurrence of the IMA, followed by a case control study. The primary outcome was to identify risk factors of IMA among the patients' medical history. Out of 2744 screened patients, 1592 patients were included during the period of November 2015 to November 2017. The rate of IMA was 5%, 81% of them presenting with intraoperative high blood pressure (HBP). In the case control study part, stepwise regression analysis revealed that a history of HBP and insulin-dependent diabetes (IDD) was significantly correlated with IMA (respectively, adjusted odds ratio 1.7, P=0.005 and 2.6, P=0.002). The low incidence of IMA showed that the SSC is a safe tool thanks to a selection and an optimised and secure pathway. A history of HBP and IDD was significantly associated with the occurrence of IMA. Therefore, an optimisation of the perioperative period would be beneficial in these cases.

Clinical, imaging and follow-up study of optic neuritis associated with myelin oligodendrocyte glycoprotein antibody: a multicentre study of 62 adult patients.

BACKGROUND AND PURPOSE: There are few clinico-radiological data on optic neuritis (ON) with myelin oligodendrocyte glycoprotein antibody (MOG-IgG). The objective was to characterize the clinico-radiological phenotype and outcome of patients with MOG-IgG-related ON. METHODS: The records of all adult patients admitted in three medical centres with MOG-IgG-associated ON who underwent orbital and brain magnetic resonance imaging (MRI) at the acute phase were reviewed. Spinal cord MRI within 1 month from the ON and all of the follow-up MRI were reviewed. RESULTS: Of 62 patients, 41.9% had bilateral ON and 66.2% optic disc swelling. On initial MRI, lesions were anterior (92%), extensive (63%) and associated with optic perineuritis (46.6%). Silent brain lesions were found in 51.8% of patients but were mainly non-specific (81%). Of 39 individuals with spinal MRI at onset, nine had abnormal findings (four were asymptomatic). Two symptomatic patients had longitudinally extensive myelitis with concurrent H-sign. At last follow-up, 5% of patients had visual acuity ≤0.1. Brain MRI remained unchanged in 41 patients (87%). CONCLUSIONS: Our study supports a mostly benign ophthalmological course of MOG-IgG-associated ON, despite initially longitudinally extensive lesions and development of optic nerve atrophy on orbital MRI. Spinal MRI could be of interest in detecting silent suggestive lesions.

Ibrutinib monotherapy for relapse or refractory primary CNS lymphoma and primary vitreoretinal lymphoma: Final analysis of the phase II 'proof-of-concept' iLOC study by the Lymphoma study association (LYSA) and the French oculo-cerebral lymphoma (LOC) network.

BACKGROUND: Primary central nervous system lymphomas (PCNSLs) are mainly diffuse large B-cell lymphomas (DLBCLs) of the non-germinal centre B-cell subtype, with unmet medical needs. This study aimed to evaluate the efficacy and toxicity of ibrutinib in DLBCL-PCNSL PATIENTS AND METHODS: This prospective, multicentre, phase II study involved patients with relapse or refractory(R/R) DLBCL-PCNSL or primary vitreoretinal lymphoma. The treatment consisted of ibrutinib (560 mg/day) until disease progression or unacceptable toxicity occurred. The primary outcome was the disease control (DC) rate after two months of treatment (P0 < 10%; P1 > 30%). RESULTS: Fifty-two patients were recruited. Forty-four patients were evaluable for response. After 2 months of treatment, the DC was 70% in evaluable patients and 62% in the intent-to-treat analysis, including 10 complete responses (19%), 17 partial responses (33%) and 5 stable diseases (10%). With a median follow-up of 25.7 months (range, 0.7-30.5), the median progression-free and overall survivals were 4.8 months (95% confidence interval [CI]; 2.8-12.7) and 19.2 months (95% CI; 7.2-NR), respectively. Thirteen patients received ibrutinib for more than 12 months. Two patients experienced pulmonary aspergillosis with a favourable (n = 1) or fatal outcome (n = 1). Ibrutinib was detectable in the cerebrospinal fluid (CSF). The clinical response to ibrutinib seemed independent of the gene mutations in the BCR pathway. CONCLUSION: Ibrutinib showed clinical activity in the brain, the CSF and the intraocular compartment and was tolerated in R/R PCNSL. The addition of ibrutinib to standard methotrexate-base induction chemotherapy will be further evaluated in the first-line treatment. CLINICAL TRIAL NUMBER: NCT02542514.

[Acute visual loss related to sphenoid meningioma]. / Troubles visuels aigus associés aux méningiomes sphénoïdaux.

Meningiomas represent about 20% of intracranial tumors. Involvement of the medial sphenoid wing includes anterior clinoid, cavernous sinus and superior orbital fissure meningiomas. Due to the proximity of these tumors to the optic nerve, typically progressive unilateral vision loss, over several months to years, is the classic clinical presentation. We report three cases of acute monocular vision loss, two transient and one permanent, ipsilateral to a sphenoid meningioma. Ophthalmological involvement with sphenoid meningiomas is most often chronic, due to interruption of axoplasmic flow and demyelination of the optic nerve by local compression. However, vascular involvement with ischemia of the optic nerve or transient low blood flow secondary to compression of the carotid branches vascularizing these structures is another possible mechanism. In our series, two patients had amaurosis fugax, and one patient had sudden, persistent visual loss in relation to acute anterior ischemic optic neuropathy on the side of the meningioma. The mean age of patients with acute visual manifestations was 62 years. These ischemic and non-compressive visual symptoms, ipsilateral to sphenoid meningiomas, are difficult to interpret. Whether these temporary visual disturbances of vascular origin should be considered an early sign of future severe or permanent visual impairment when no optic nerve compression is observed is not certain. The place of these acute visual disturbances in the therapeutic decision, particularly surgical, remains to be defined. Larger multicentric prospective studies are needed to better understand the role of local circulatory factors attributable to meningioma in the occurrence of these acute visual signs.

[Raxone in the Leber optical neuropathy: Parisian experience]. / Raxone dans la neuropathie optique de Leber : retour d'expérience parisienne.

INTRODUCTION: Leber's Hereditary Optic Neuropathy (LHON) causes a rapid and severe decrease in visual acuity. Raxone® (Idebenone, Santhera) is the only drug to have a European Marketing Authorization for the treatment of this optic neuropathy. It can be proposed in the first months after the onset of this optic neuropathy, according to an international consensus meeting. PATIENTS AND METHODS: Retrospective study of the efficacy of Raxone® on the visual acuity of patients with genetically confirmed LHON who were followed in four Parisian hospitals. The primary endpoint is the best recovery of LogMar visual acuity between baseline and the end of follow-up. The secondary endpoints are the evolution of LogMar visual acuity of the best eye at baseline and change in LogMar visual acuity for each eye considered separately. RESULTS: Seventeen patients, three women and 14 men, mean age 34.2 years, naive to treatment with Raxone® were included in this study. The mean duration of treatment was 11.0±6.6 months. A mitochondrial DNA mutation was found in all patients. Only 2 had the 14484 mutation. A recovery of better LogMar visual acuity was found at the end of the treatment for 4 eyes (23.5 %), and a deterioration was observed for 8 (47.0 %). Only 2 eyes (11.7 %) with the best visual acuity at baseline improved. On the other hand, 17.6 % of the eyes considered separately had an improvement in their LogMar visual acuity at the end of the treatment. CONCLUSION: The results confirm the trend of Raxone® treatment to improve patients' visual acuity. Given the recommendations of a consensus conference, this treatment should be started early after the onset of LHON. It is therefore important to look for this diagnosis in the presence of any hereditary optic neuropathy, in order to be able to initiate this treatment.

Lenalidomide in combination with intravenous rituximab (REVRI) in relapsed/refractory primary CNS lymphoma or primary intraocular lymphoma: a multicenter prospective 'proof of concept' phase II study of the French Oculo-Cerebral lymphoma (LOC) Network and the Lymphoma Study Association (LYSA)†.

BACKGROUND: Primary central nervous system lymphomas (PCNSLs) are mainly diffuse large B-cell lymphomas (DLBCLs) of the non-germinal center B-cell (non-GCB) subtype. This study aimed to determine the efficacy of rituximab plus lenalidomide (R2) in DLBCL-PCNSL. PATIENTS AND METHODS: Patients with refractory/relapsed (R/R) DLBCL-PCNSL or primary vitreoretinal lymphoma (PVRL) were included in this prospective phase II study. The induction treatment consisted of eight 28-day cycles of R2 (rituximab 375/m2 i.v. D1; lenalidomide 20 mg/day, D1-21 for cycle 1; and 25 mg/day, D1-21 for the subsequent cycles); in responding patients, the induction treatment was followed by a maintenance phase comprising 12 28-day cycles of lenalidomide alone (10 mg/day, D1-21). The primary end point was the overall response rate (ORR) at the end of induction (P0 = 10%; P1 = 30%). RESULTS: Fifty patients were included. Forty-five patients (PCNSL, N = 34; PVRL, N = 11) were assessable for response. The ORR at the end of induction was 35.6% (95% CI 21.9-51.2) in assessable patients and 32.0% (95% CI 21.9-51.2) in the intent-to-treat analysis, including 13 complete responses (CR)/unconfirmed CR (uCR; 29%) and 3 partial responses (PR; 7%). The best responses were 18 CR/uCR (40%) and 12 PR (27%) during the induction phase. The maintenance phase was started and completed by 18 and 5 patients, respectively. With a median follow-up of 19.2 months (range 1.5-31), the median progression-free survival (PFS) and overall survival (OS) were 7.8 months (95% CI 3.9-11.3) and 17.7 months (95% CI 12.9 to not reached), respectively. No unexpected toxicity was observed. The peripheral baseline CD4/CD8 ratio impacted PFS [median PFS = 9.5 months (95% CI, 8.1-14.8] for CD4/CD8 ≥ 1.6; median PFS = 2.8 months, [95% CI, 1.1-7.8) for CD4/CD8 < 1.6, P = 0.03). CONCLUSIONS: The R2 regimen showed significant activity in R/R PCNSL and PVRL patients. These results support assessments of the efficacy of R2 combined with methotrexate-based chemotherapy as a first-line treatment of PCNSL. CLINICAL TRIALS NUMBER: NCT01956695.

Anakinra in the Treatment of Patients with Refractory Scleritis: A Pilot Study.

PURPOSE: This study aimed to evaluate the safety and efficacy of anakinra for severe and refractory scleritis. METHODS: Ten patients with severe (i.e. at least 2 ocular relapses per year despite treatment) and refractory [i.e. at least to one disease modifying antirheumatic drugs (DMARDS)] scleritis were treated with anakinra (100 mg/day subcutaneously). Scleritis was associated with inflammatory systemic diseases in 60% of cases. The remission rate defined the primary outcome. RESULTS: Ninety percent of patients were complete responders with a mean follow-up of 19.4 months after starting anakinra. The corticosteroids daily dose decreased from 18.3 ± 4.1 mg to 4.2 ± 4.9 mg, (p < 0.05), at initiation of anakinra and at end of follow-up, respectively. Associated immunosuppressants were stopped in all cases except one. Side effects were observed in 4 patients who did not need anakinra withdrawal. CONCLUSIONS: This pilot study suggests the efficacy of anakinra in patients with refractory scleritis.

Neuro-ophthalmological conditions: Study of the clinical care pathway.

INTRODUCTION: Neuro-ophthalmologic conditions require specialized multidisciplinary management, both medical and surgical, for patients affected by visual loss due to nervous system disease. The primary goal of this study is to define the specificity of neuro-ophthalmology within the realm of visual health. The secondary goal is to review clinical care pathways by studying the organization of management, in terms of accessibility to care and personalization of the care pathway. PATIENTS AND METHODS: A field study was carried out from February to June 2015, within the ophthalmology service of the Pitié-Salpêtrière University Medical Center in Paris. A 30-minute interview with the patient before or after his or her neuro-ophthalmology consultation was performed, to describe the clinical care pathway. The medical records of interviewed patients were also analyzed. RESULTS: Seventeen care pathways (10 women and 7 men) were reviewed. The mean age at appearance of visual involvement was 44.5 years (±8.4 years). If we exclude 3 patients over 66 years and retired, 35.71% were active, 35.71% were disabled, and 28.57% were on sick leave. Ten patients (58.82%) met the criteria for admission to long-term care. The first step had been carried out by local private practitioners. The first physician seen was the general medicine physician (59%), then the private ophthalmologist on an emergency basis (17%). On average, patients went through 8 steps during their care pathway (from 6 to 10 steps) and 14 medical departments were involved. The study showed collaboration with the other services of the University Hospital Department of Vision and Disabilities (notably with the Fondation Rothschild, the Quinze-Vingts National Ophthalmology Hospital, and the Fondation Sainte-Marie). In addition to rehabilitation services, health care professionals participating in the outpatient care of the patients included an orthoptist (11.7%), a psychologist (11.7%), and an optician specializing in low vision for visual aids. Finally, patient support groups, AFM-Téléthon (myasthenia) and the ARIBa association (visual disability) were solicited by 2 patients for their involvement. A disturbance in activities of daily living leading to disabilities with psychological repercussions was noted by a number of patients. The most frequent complaints involve mobility (29.41%) and reading (23.52%). In total, 77% of patients state that their well-being has been affected, and they are disturbed by the progression of their disease. DISCUSSION AND CONCLUSIONS: The review of the clinical care pathway of patients affected by neuro-ophthalmological conditions shows that these pathologies are, on the one hand, often poorly understood, and on the other hand complex, leading to an often significant number of steps for the patient. This also emphasizes the necessity of a care network, specialized and structured to improve the efficiency of this management. Finally, these results demonstrate the existence of a very frequent disability, which may affect all aspects of the patients' lives, highlighting the importance of rehabilitation services and individuals participating in the follow-up of these patients beyond their acute care.

[Neuro-ophthalmological conditions: Study of the clinical care pathway]. / Les affections neuro-ophtalmologiques : étude du parcours de soins du patient.

INTRODUCTION: Neuro-ophthalmologic conditions require specialized multidisciplinary management, both medical and surgical, for patients affected by visual loss due to nervous system disease. The primary goal of this study is to define the specificity of neuro-ophthalmology within the realm of visual health. The secondary goal is to review clinical care pathways by studying the organization of management, in terms of accessibility to care and personalization of the care pathway. PATIENTS AND METHODS: A field study was carried out from February to June 2015, within the ophthalmology service of the Pitié-Salpêtrière University Medical Center in Paris. A 30-minute interview with the patient before or after his or her neuro-ophthalmology consultation was performed, so as to describe the clinical care pathway. The medical records of interviewed patients were also analyzed. RESULTS: Seventeen care pathways (10 women and 7 men) were reviewed. The mean age at appearance of visual involvement was 44.5 years (±8.4 years). If we exclude 3 patients over 66 years and retired, 35.71% were active, 35.71% were disabled, and 28.57% were on sick leave. Ten patients (58.82%) met the criteria for admission to long-term care. The first step had been carried out by local private practitioners. The first physician seen was the general medicine physician (59%), then the private ophthalmologist on an emergency basis (17%). On average, patients went through 8 steps during their care pathway (from 6 to 10 steps) and 14 medical departments were involved. The study showed collaboration with the other services of the University Hospital Department of Vision and Disabilities (notably with the Fondation Rothschild, the Quinze-Vingts National Ophthalmology Hospital and the Fondation Sainte-Marie). In addition to rehabilitation services, health care professionals participating in the outpatient care of the patients included an orthoptist (11.7%), a psychologist (11.7%), and an optician specializing in low vision for visual aids. And finally, patient support groups, AFM-Téléthon (myasthenia) and the ARIBa Association (visual disability) were solicited by 2 patients for their involvement. A disturbance in activities of daily living leading to disabilities with psychological repercussions was noted by a number of patients. The most frequent complaints involve mobility (29.41%) and reading (23.52%). In total, 77% of patients state that their well-being has been affected and they are disturbed by the progression of their disease. DISCUSSION AND CONCLUSIONS: The review of the clinical care pathway of patients affected by neuro-ophthalmological conditions shows that these pathologies are, on the one hand, often poorly understood, and on the other hand complex, leading to an often significant number of steps for the patient. This also emphasizes the necessity of a care network, specialized and structured to improve the efficiency of this management. Finally, these results demonstrate the existence of a very frequent disability, which may affect all aspects of the patients' lives, highlighting the importance of rehabilitation services and individuals participating in the follow-up of these patients beyond their acute care.

High-dose thiotepa-based chemotherapy with autologous stem cell support in elderly patients with primary central nervous system lymphoma: a European retrospective study.

In this retrospective multicentre study, we investigated the outcomes of elderly primary central nervous system lymphoma (PCNSL) patients (⩾65 years) who underwent high-dose chemotherapy followed by autologous stem cell transplantation (HDT-ASCT) at 11 centres between 2003 and 2016. End points included remission, progression-free survival (PFS), overall survival (OS) and treatment-related mortality. We identified 52 patients (median age 68.5 years, median Karnofsky Performance Status before HDT-ASCT 80%) who all underwent thiotepa-based HDT-ASCT. Fifteen patients (28.8%) received HDT-ASCT as first-line treatment and 37 (71.2%) received it as second or subsequent line. Remission status before HDT-ASCT was: CR 34.6%, PR 51.9%, stable disease 3.8% and progressive disease 9.6%. Following completion of HDT-ASCT, 36 patients (69.2%) achieved CR (21.2% first-line setting and 48.1% second or subsequent line setting) and 9 (17.3%) PR (5.8% first-line setting and 11.5% second or subsequent line setting). With a median follow-up of 22 months after HDT-ASCT, median PFS and OS were reached after 51.1 and 122.3 months, respectively. The 2-year PFS and OS rates were 62.0% and 70.8%, respectively. We observed two HDT-ASCT-associated deaths (3.8%). In selected elderly PCNSL patients, HDT-ASCT, using thiotepa-based conditioning regimes, is feasible and effective. Further prospective and comparative studies are warranted to further evaluate the role of HDT-ASCT in elderly PCNSL patients.

[Birdshot retinochoroidopathy: Key messages]. / Rétinochoroïdopathie de type Birdshot : les éléments clés.

Birdshot retinochoroidopathy (BRC) is a potentially blinding posterior autoimmune uveitis that affects Caucasian patients in their fifties. Strongly associated with the HLA A 29 phenotype, BRC is characterized by the presence of suggestive choroidal lesions on the fundus, but their apparition can be delayed. Visual acuity is not a good descriptive factor of visual function. Ancillary tests can therefore help establish the diagnosis and allow proper follow-up of BRC patients: optical coherence tomography can reveal either oedema or atrophy of the macula. Fluorescein and infracyanine green angiograms can show signs of inflammatory activity and give further diagnostic clues. Electroretinograms and visual fields can be useful for the diagnosis and follow-up. BCR patients should be examined periodically and undergo exhaustive clinical and paraclinical tests to insure the best prognosis. Corticosteroids should be associated with immunosuppressive treatments as early as possible in the presence of factors that are predictive of the worse prognoses.

Evaluation of the visual function of patients with locked-in syndrome: Report of 13 cases.

Although visual function is thought to be preserved in patients with locked-in syndrome (LIS), enabling them to communicate through vertical or lateral eye movements or blinking of the upper eyelid, nothing is known about the actual visual function of patients with LIS. The goal of this study is to evaluate the visual function of patients with LIS which may enable better evaluation of the state of consciousness of these patients. Patients with LIS seen in a single neurovascular unit of a tertiary center between 1997 and 2013 were retrospectively reviewed. Each patient had a specialized neuro-ophthalmological evaluation under optimal environmental conditions (light, contrast, examination distance, head position, best ergonomic adaptation, and establishment of a means of communication with help from the patient's friends/family). Visual acuity, extraocular eye movements, confrontational visual field, slit lamp and fundus examination were performed. Thirteen patients (6M/7F) were included in this study. Mean visual acuity was 20/60. Oculomotor examination was abnormal in 77%. Forty-six percent of patients presented binocular diplopia mainly related to a VIth nerve palsy. One patient presented complete ophthalmoplegia. Forty-six percent of patients had nystagmus responsible for oscillopsia (oculopalatal tremor). An abnormal visual field was observed in 17% of patients, and abnormal pupillary light response leading to photophobia was present in 22% of patients. Keratitis or dry eye syndrome was present in most patients and was a major cause of pain and visual impairment. Our results suggest that the visual function is impaired in all patients with LIS. This impairment is multifactorial including mostly binocular diplopia or oscillopsia but also refractive errors, dry eye syndrome, keratitis or visual field defect. This altered visual function may alter the ability of the patient to interact with his environment and lead to underestimation of their state of consciousness. An ophthalmologic evaluation would allow for improvement of these patients' comfort, their ability to communicate, and the assessment of their state of consciousness.

[Carotid-cavernous fistula: clinical and pathological correlations]. / Fistules carotido-caverneuses: corrélation anatomo-clinique.

INTRODUCTION: Depending upon the type of communication between the internal carotid artery and the cavernous sinus, two types of carotid-cavernous fistulae can be distinguished: direct carotid-cavernous fistula (DCCF), for which diagnosis is usually easy because of the obvious signs of orbital congestion, and indirect carotid-cavernous fistula (ICCF) or dural fistula, with few symptoms, associated with a delay in diagnosis which can alter prognosis for function and even life. PURPOSE: The purpose of this study is to determine characteristic signs of both types of CCF and to study their correlation with the anatomical type of vessels involved on the angiogram. The prognosis for both types of fistula was also studied. METHOD: Retrospective single-center study, including patients with angiographically confirmed DCCF or ICCF. Demographic, clinical, and prognostic characteristics of these patients were analyzed and compared with the angiogram findings. RESULTS: Six patients (4 DCCF and 2 ICCF) were included in this study. Mean age at diagnosis was 62.7 years in the DCCF group and 62 years in the ICCF group. Mean time until diagnosis was 7 weeks in the DCCF group and 24 weeks in the ICCF group. Signs of orbital congestion were present in 100% of patients with DCCF and absent in all patients in the ICCF group. Mean proptosis was 3.5mm in the DCCF group and 0.5 in the ICCF group. All patients had an audible bruit on auscultation. The location of the bruit was orbital in all patients with DCCF, and pretragal or jugal in 50% of patients with ICCF. CONCLUSIONS: ICCF can impact mortality and are often underdiagnosed. The diagnostic delay observed in our study reflects the difficulties which persist in recognizing the clinical signs of this condition. ICCF must be suspected in the case of a history suggestive of CCF, even if the clinical examination appears normal. The presence of a bruit must be carefully sought, not only in the classical orbital location, but also in other facial locations as shown in our study. Our results demonstrate that there is indeed a good correlation between the site of the CCF, the location of the bruit, and the vessels involved.

[Bitemporal hemianopia as presenting sign of severe ethambutol toxicity]. / Hémianopsie bitemporale révélatrice d'une atteinte toxique sévère à l'éthambutol.

INTRODUCTION: Optic neuropathy is a severe and well-known complication of ethambutol treatment. If not detected early, it may lead to profound and irreversible vision loss. CASE REPORT: We report the case of a 83-year-old female patient, referred for rapidly progressive, painless, bilateral visual loss, unimproved after bilateral cataract surgery. Automated Humphrey 24-2 visual field demonstrated bitemporal hemianopia associated with bilateral central scotoma. Brain MRI did not demonstrate any compressive lesion in the chiasmal region. However, on T2-weighted sequences, an area of elevated signal intensity appeared within the optic chiasm, enhancing after gadolinium injection. On detailed history, it was noted that the patient had been on ethambutol for the last 18months, for the treatment of a Mycobacterium avium-related pneumonitis. DISCUSSION: The incidence of ethambutol-related toxic optic neuropathy has dramatically decreased since the recommendations for regular follow-up of patients treated with ethambutol. This treatment is classically responsible for bilateral central or ceco-central scotoma due to optic neuropathy, although a few cases of bitemporal hemianopia have been reported in the literature, mimicking a compressive chiasmal lesion. However, none of these cases demonstrated a hypersignal in the optic chiasm on brain magnetic resonance imaging (MRI). CONCLUSION: Bitemporal hemianopia on visual field testing is very suggestive of a chiasmal lesion, which is generally due to a compressive, or more rarely inflammatory, lesion in the sellar region. Toxic chiasmal lesions are rare, but in the absence of any tumoral lesion in the sellar area, a detailed history must be obtained in order to rule out drug toxicity, so as to prevent irreversible visual loss.