[Neuroradiology for the Ophthalmologist - Part 2 Efference]. / Neuroradiologie für den Augenarzt. Teil 2: Efferenz.

Eye movements are a complex task requiring a large number of structures coordinated by three cranial nerves and their centres in the brainstem. Various pathologies may affect any part of the pathway controlling the eye movements and their diagnosis is often based on history and clinical examination. Modern advances in computed tomography and magnetic resonance imaging have recently added a valuable tool in the diagnosis of oculo-motor-related diseases.

Stereoptic serious games as a visual rehabilitation tool for individuals with a residual amblyopia (AMBER trial): a protocol for a crossover randomized controlled trial.

BACKGROUND: Amblyopia is the most common developmental vision disorder in children. The initial treatment consists of refractive correction. When insufficient, occlusion therapy may further improve visual acuity. However, the challenges and compliance issues associated with occlusion therapy may result in treatment failure and residual amblyopia. Virtual reality (VR) games developed to improve visual function have shown positive preliminary results. The aim of this study is to determine the efficacy of these games to improve vision, attention, and motor skills in patients with residual amblyopia and identify brain-related changes. We hypothesize that a VR-based training with the suggested ingredients (3D cues and rich feedback), combined with increasing the difficulty level and the use of various games in a home-based environment is crucial for treatment efficacy of vision recovery, and may be particularly effective in children. METHODS: The AMBER study is a randomized, cross-over, controlled trial designed to assess the effect of binocular stimulation (VR-based stereoptic serious games) in individuals with residual amblyopia (n = 30, 6-35 years of age), compared to refractive correction on vision, selective attention and motor control skills. Additionally, they will be compared to a control group of age-matched healthy individuals (n = 30) to account for the unique benefit of VR-based serious games. All participants will play serious games 30 min per day, 5 days per week, for 8 weeks. The games are delivered with the Vivid Vision Home software. The amblyopic cohort will receive both treatments in a randomized order according to the type of amblyopia, while the control group will only receive the VR-based stereoscopic serious games. The primary outcome is visual acuity in the amblyopic eye. Secondary outcomes include stereoacuity, functional vision, cortical visual responses, selective attention, and motor control. The outcomes will be measured before and after each treatment with 8-week follow-up. DISCUSSION: The VR-based games used in this study have been conceived to deliver binocular visual stimulation tailored to the individual visual needs of the patient, which will potentially result in improved basic and functional vision skills as well as visual attention and motor control skills. TRIAL REGISTRATION: This protocol is registered on ClinicalTrials.gov (identifier: NCT05114252) and in the Swiss National Clinical Trials Portal (identifier: SNCTP000005024).

Orbital Fractures With Concomitant Ocular Nerve Palsy: An Insidious and Potentially Misleading Association in Surgical Decision-Making.

PURPOSE: Orbital fractures (OFs) are common, but their association with concomitant traumatic ocular nerve palsy (TONP) is exceptional and may potentially cause confusing clinical pictures of oculomotor involvement. The purpose of the present study is to describe a series of patients with OFs and concomitant TONP following facial trauma and to evaluate clinical features, diagnostic pitfalls, and final functional outcome. METHODS: The investigators designed and implemented a retrospective case series and enrolled a sample of patients with OFs and concomitant TONP who had been managed at the University Hospitals of Geneva between 2013 and 2020. The primary outcomes were clinical pitfalls (diagnosis of neurogenic vs restrictive ocular motility pattern at baseline) and final functional outcome (persistent symptomatic diplopia). Other study variables included demographic and injury related parameters. RESULTS: The sample was composed of 10 patients with a mean age of 40.7 ± 12.3 years (range 21 to 53 years) and 80% were men. In all patients, the diagnosis of the neurogenic component accounted for the main diagnostic pitfalls associated to the baseline post-traumatic limitation of ocular motility and diplopia. Six patients (60%) had a full spontaneous recovery of their diplopia. Four patients (40%) had a partial recovery with residual diplopia. Of these 4 patients, 1 patient underwent corrective strabismus surgery, 2 had temporary occlusion of 1 eye, and 1 had Fresnel prisms. At the final follow-up visit none of the patients had persistent symptomatic diplopia. CONCLUSIONS: The present study has shown that OFs with concomitant TONP entail complex ocular motility patterns of neurogenic and/or restrictive origin; the diagnosis of the neurogenic component represents the main clinical pitfall that warrants a careful orthoptic evaluation to ensure the appropriate management; the final outcome was favorable with no persistent symptomatic diplopia in any of the patients.

[Accommodation]. / Akkommodation.

Accommodation is the natural increase or decrease of the refraction of the eye lens as a function of the fixation distance. It relies on the proper elasticity of the natural eye lens. The evaluation of accommodation and the coupled convergent eye movements enables us to make the diagnosis of certain eye-related conditions and allows the differential diagnostic from some of the "neuroophthalmic diseases". This may avoid some unnecessary diagnostic procedures and reduce patient anxiety in terms of having a health threatening disease.

[Neuroradiology for the Ophthalmologist]. / Neuroradiologie für den Augenarzt.

Computer tomography (CT) and magnet resonance imaging (MRI) are valuable imaging tools in order to examine various pathologies of the visual pathways. The advantage of CT is its short acquisition time of a few minutes, its availability making it an ideal tool in emergency medicine. It is extremely valuable in patients with cranio-cerebral trauma when an orbital or skull fracture or an intracerebral haemorrhage has to be assessed. In addition, CT-Angiography is used in the management of patients with an acute stroke. CT is mandatory to visualize the orbit in many conditions. The most important disadvantage is its use of ionizing radiation. Thus, CT is contraindicated in pregnant woman. Contrast of soft tissue as brain tissue is inferior compared to MRI. The latter has a high sensitivity in visualizing all kind of brain pathologies including tumours, inflammatory conditions or brain oedema as a result of a stroke. In contrast to CT, MRI (without contrast agent) can be used in pregnant women. The disadvantages of MRI are its long acquisition time, its contraindication in patients with metallic implants including pacemaker and its low resolution of bony tissue. Both imaging tools are often used in a complementary way in many orbital diseases, pathologies affecting bony structures, pathologies with calcifications and in stroke patients.

[Cavernous hemangioma of the orbit: diagnosis and management]. / Hémangiome caverneux de l'orbite: diagnostic et prise en charge.

The cavernous hemangioma (or angioma) of the orbit (HCO) is a benign, encapsulated venous malformation and the most common primary lesion of the orbit in adults. It occurs more often in women. These lesions can cause a unilateral proptosis (exophthalmos), optic nerve damage and other signs of orbital pathology, with varying degrees of visual impairment.When an HCO is suspected, ultrasound, scanner or magnetic resonance imaging (MRI) are a valuable aid to its definitive diagnosis. When HCO is symptomatic, multidisciplinary surgical management by a trained specialist in orbital surgery should be considered.This article aims to present the surgical management of HCO. Topographic classifications and surgical approaches are also discussed.

L'hémangiome caverneux (ou angiome) de l'orbite (HCO) est une malformation veineuse encapsulée bénigne et la lésion primaire la plus courante de l'orbite chez l'adulte. Elle survient plus souvent chez les femmes. Ces lésions peuvent provoquer une proptose unilatérale (exophtalmie), des lésions du nerf optique et d'autres signes de pathologie orbitaire, avec une déficience visuelle.Lorsqu'un HCO est suspecté, l'échographie, le scanner ou l'IRM sont une aide précieuse pour son diagnostic définitif. Lorsque l'HCO est symptomatique, une prise en charge chirurgicale multidisciplinaire par un spécialiste de la chirurgie orbitaire doit être envisagée.Cet article vise à présenter la prise en charge chirurgicale du HCO. Les classifications topographiques et les approches chirurgicales sont également discutées.

[Non-organic Visual Loss]. / Nicht organische Sehstörungen.

Non-organic visual loss is a frequent challenge in ophthalmic practice. In children most patients are prepubertal females. The most frequent manifestation in this age-group is a bilateral unexplained decrease of visual acuity. In adulthood patients often indicate a degree of visual loss after an accident or a disease - that could not be explained by the eye condition alone. Non-organic visual loss may be frustrating for both, patients and physicians. The aim of the present article is to sensitize ophthalmologists to this condition and to provide a diagnostic frame and strategy how to manage patients with such a diagnosis.

Case Report: Masquerading Large-vessel Giant Cell Arteritis.

SIGNIFICANCE: Large-vessel giant cell arteritis (GCA) can be a diagnostic dilemma for the eye care provider because it may not involve the typical cranial arteries. When any of its potential ocular complications are diagnosed, it is important to consider this unusual form of GCA. PURPOSE: To report an unusual ophthalmic presentation of large-vessel GCA with sequential bilateral anterior ischemic optic neuropathy and branch retinal artery occlusion. METHODS: A 65-year-old previously healthy woman experienced sequential bilateral anterior ischemic optic neuropathy with branch retinal artery occlusion in the absence of other signs and symptoms suggestive of cranial GCA. RESULTS: Extensive workup, including temporal artery biopsy, failed to demonstrate vascular inflammation suggestive of GCA or vascular abnormalities, such as atheromatous plaques, but coincidentally revealed a breast tumor, which was excised. Positron emission tomography scan was performed revealing distinct hypermetabolism of the thoracic and abdominal aorta consistent with large-vessel GCA, and corticosteroid therapy was initiated. CONCLUSIONS: Large-vessel GCA is an underdiagnosed and undertreated type of GCA that does not typically affect the cranial arteries but rather larger proximal aortic branches. When associated with ocular complications, it can be a puzzling diagnostic dilemma for the eye care provider.

[Optic neuritis: diagnosis, treatment and clinical implications]. / Névrite du nerf optique: diagnostic, traitement et implications cliniques.

Optic neuritis is one of the most important causes of visual loss in young and middle aged adults. The prognosis in terms of functional outcome is good. The diagnosis of optic neuritis is a clinical one. Steroids can shorten the recovery time but do not change the long term functional outcome. The MRI is the most important investiga- tion to assess an associated risk of multiple sclerosis. Optic cohe- rence tomography (OCT) contribute additional details to course and functional outcome of optic neuritis. In the future the OCT may additionally contribute to the relationship between optic neuritis and possible associated multiple sclerosis.

The use of diffusion magnetic resonance imaging tractography in supporting anatomical conflict between an uncal protrusion and the oculomotor nerve: A case report of isolated inferior rectus palsy.

Background: Isolated inferior rectus muscle palsy is a rare entity and even more rarely induced by an anatomical conflict. We report here a clinical case of third cranial nerve (CN III) compression in its cisternal segment by an idiopathic uncal protrusion in a patient presenting an isolated inferior rectus muscle palsy. Case Description: We report a case of an anatomical conflict between the uncus and the CN III in the form of a protrusion and highly asymmetrical proximity of the uncus and asymmetrically thinned nerve diameter deviated from its straight cisternal trajectory on the ipsilateral side were supported by an altered diffusion tractography along the concerned CN III. Clinical description, review of the literature, and image analysis were done including CN III fiber reconstruction using a fused image from diffusion tensor imaging images, constructive interference in steady state, and T2-fluid-attenuated inversion recovery images on a dedicated software (BrainLAB AG). Conclusion: This case illustrates the importance of anatomical-clinical correlation in cases of CN deficits and supports the use of new neuroradiologically based interrogation methods such as CN diffusion tractography to support anatomical CN conflicts.

[Supranuclear eye movement disorders]. / Supranukleäre Augenbewegungsstörungen.

Eye movements are performed in order to either focus the gaze onto a new interesting object or to stabilize the viewed object in the fovea. As every type of eye movement has its own anatomical substrate, it is often possible to localize an eye movement disorder to a specific brain region or to make a diagnosis of a systemic disease in an appropriate clinical setting. Thus, in many patients the assessment of eye movements can effectively help in the diagnosis and appropriate treatment can be initiated in a timely manner.

Blinded by Zika? A missed HIV diagnosis that resulted in optic neuropathy and blindness: a case report.

BACKGROUND: Typical symptoms of an acute human immunodeficiency virus (HIV) infections like fever and rash are not specific and can be caused by a multitude of other pathogens, such as Zika or rickettsiosis. Up to 30% of primary HIV infection do not present with the typical flu-like symptoms and thus represent a diagnostic challenge. In this report, we describe a rare case of optic neuropathy as the initial presentation of primary HIV infection, which resulted in irreversible blindness. To our knowledge, only four cases of optic neuropathy resulting from a recent HIV seroconversion have been reported. CASE PRESENTATION: In January 2015, a 72-year-old man presented with a rash, fever and diffuse myalgias after returning from a fortnight in Cuba. In the context of the current polemic, Zika was considered likely. A diagnostic work-up, including dengue fever and Zika, was negative. Symptoms resolved spontaneously. In March, the patient experienced a sudden loss of vision first on one, a few days later on the other eye. Magnetic resonance imaging showed optic nerve enhancement suggesting neuritis. Numerous infective causes were sought and the patient was diagnosed with HIV. Corticosteroids and antiretroviral therapy were initiated but vision did not improve. Four weeks later an optic atrophy developed. After more than a year of follow-up the patient remains blind. Stored serum from January revealed a detectable viremia with a negative Western blot assay, typical of acute HIV infection. CONCLUSIONS: Optic neuritis is a rare complication of early HIV infection. Only four others cases have been described, some of which recovered their vision after the administration of corticosteroids and/or ARV treatment. The balance between ischemic and neuroimmune processes may play a role in recovery. Delayed diagnosis, due to an unjustified focus on the Zika virus may have contributed to the tragic outcome.

Changes in Listing's plane after sustained vertical fusion.

PURPOSE: To determine whether prolonged fusion of an imposed vertical disparity leads to a change in the orientation of Listing's plane, even when measured during monocular viewing. METHODS: Four normal subjects (age range, 24-37 years) wore Fresnel prisms of increasing power for 72 hours to produce a final left-over-right disparity (range, 7-11 prism diopters [approximately 3.9 - 6.2 degrees]) that was still fusible. Eye movements were measured binocularly, using three-axis search coils, as subjects fixed on an array of light-emitting diodes (LEDs) arranged on a flat screen, 124 cm away. A regression was used to fit the data points to a plane (Listing's plane) during monocular and binocular viewing. From each planar fit, the horizontal and vertical components of primary position (the direction of gaze that is perpendicular to Listing's plane) were calculated. Baseline data were collected in the unadapted state, either just before or at least 4 days after wearing the prisms. RESULTS: After the period of viewing through the prisms, there was a change in vertical phoria (prism adaptation) ranging from 1.6 to 3.3. There was a significant (P < 0.01) shift of the relative orientation of the vertical component of primary position between the two eyes of 6.3 +/- 1.7 degrees (right eye value minus left eye, up being positive, each measured during monocular viewing). There was no consistent pattern of change in the horizontal component of primary position. CONCLUSIONS: Prolonged fusion of a vertical disparity is associated with a change in the orientation of Listing's plane that persists under monocular viewing. Possible mechanisms include phoria adaptation, the prolonged fusional effort itself, and the residual disparity that must be overcome by sensory mechanisms.

Primary position and listing's law in acquired and congenital trochlear nerve palsy.

PURPOSE: In ocular kinematics, the primary position (PP) of the eye is defined by the position from which movements do not induce ocular rotations around the line of sight (Helmholtz). PP is mathematically linked to the orientation of Listing's plane. This study was conducted to determine whether PP is affected differently in patients with clinically diagnosed congenital (conTNP) and acquired (acqTNP) trochlear nerve palsy. METHODS: Patients with unilateral conTNP (n = 25) and acqTNP (n = 9) performed a modified Hess screen test. Three-dimensional eye positions were recorded with dual search coils. RESULTS: PP in eyes with acqTNP was significantly more temporal (mean: 21.2 degrees ) than in eyes with conTNP (6.8 degrees ) or healthy eyes (7.2 degrees ). In the pooled data of all patients, the horizontal location of PP significantly correlated with vertical noncomitance with the paretic eye in adduction (R = 0.59). Using a computer model, PP in acqTNP could be reproduced by a neural lesion of the superior oblique (SO) muscle. An additional simulated overaction of the inferior oblique (IO) muscle moved PP back to normal, as in conTNP. Lengthening the SO and shortening the IO muscles could also simulate PP in conTNP. CONCLUSIONS: The temporal displacement of PP in acqTNP is a direct consequence of the reduced force of the SO muscle. The reversal of this temporal displacement of PP, which occurs in some patients with conTNP, can be explained by a secondary overaction of the IO muscle. Alternatively, length changes in the SO and IO muscles, or other anatomic anomalies within the orbit, without a neural lesion, may also explain the difference in location of PP between conTNP and acqTNP.

Motor mechanisms of vertical fusion in individuals with superior oblique paresis.

PURPOSE: We wanted to determine the mechanisms of motor vertical fusion in patients with superior oblique paresis and to correlate these mechanisms with surgical outcomes. METHODS: Ten patients with superior oblique paresis underwent 3-axis, bilateral, scleral search coil eye movement recordings. Eye movements associated with fusion were analyzed. RESULTS: Six patients had decompensated congenital superior oblique paresis and 4 had acquired superior oblique paresis. All patients with acquired superior oblique paresis relied predominantly on the vertical rectus muscles for motor fusion. Patients with congenital superior oblique paresis were less uniform in their mechanisms for motor fusion: 2 patients used predominantly the oblique muscles, 2 patients used predominantly the vertical recti, and 2 patients used predominantly the superior oblique in the hyperdeviated eye and the superior rectus in the hypodeviated eye. The last 2 patients developed the largest changes in torsional eye alignment relative to changes in vertical eye alignment and were the only patients to develop symptomatic surgical overcorrections. CONCLUSION: There are 3 different mechanisms for vertical fusion in individuals with superior oblique paresis, with the predominant mechanism being the vertical recti. A subset of patients with superior oblique paresis uses predominantly the superior oblique muscle in the hyperdeviated paretic eye and the superior rectus muscle in the fellow eye for fusion. This results in intorsion of both eyes, causing a large change in torsional alignment. The consequent cyclodisparity, in addition to the existing vertical deviation, may make fusion difficult. The differing patterns of vertical fusional vergence may have implications for surgical treatment.

Torsion in patients with superior oblique palsies: dynamic torsion during saccades and changes in Listing's plane.

BACKGROUND: The purpose was to assess intra- and post-saccadic torsion in superior oblique palsy (SOP) patients and the effect of surgery on torsion. METHODS: Eleven patients with a presumed congenital SOP and five with acquired SOP performed 10 degrees vertical saccades over a range of +/-20 degrees. Eye movements were recorded with dual search coils. Dynamic torsion was calculated by subtracting the expected change in torsion during the saccade (based upon static torsion before and after the saccade) from the maximum intrasaccadic torsion. Eight healthy subjects were controls. We also examined the effects of surgery on dynamic torsion and the orientation of Listing's plane in patients with congenital SOP who were operated on either by weakening of the inferior oblique muscle on the affected eye (n=5), by recession of the inferior rectus muscle on the normal eye (n=4) or by both procedures (n=2). Postoperative recordings were obtained at least 1 month after surgery. RESULTS: Patients with congenital and acquired SOP showed an increased dynamic extorsion, primarily during downward saccades. Following a recession of the inferior oblique muscle in congenital SOP patients, half showed significant decreases in extorsion (up to 1.0 degrees) during downward saccades by the affected eye. Following surgery all showed a temporal rotation of Listing's plane (up to 15 degrees for primary position). CONCLUSION: Patients with a SOP show a characteristic pattern of dynamic torsion during vertical saccades differing from normals. Recession of the inferior oblique muscle leads to rotation of Listing's plane in all congenital SOP patients and causes large changes in dynamic torsion in a subgroup of them, perhaps reflecting the heterogeneity of congenital SOP.

Long-term results of surgery in childhood glaucoma.

PURPOSE: The aim of this study is to assess the functional results and morphological parameters in children surgically treated for glaucoma. METHODS: Data from 43 patients and 68 eyes who were operated in our department between 1990 and 2002 were collected. This retrospective trial included primary congenital glaucoma (n=36), and secondary glaucoma (n=7) in Rieger-Axenfeld syndrome and Sturge Weber syndrome. Intraocular pressure (IOP), axial length of the eyeball, visual acuity, refractive errors and orthoptic status were analysed. RESULTS: The age of patients at the first surgery was 6.0 +/- 5.3 months (range 0.7 to 28.0 months). The mean period of follow-up was 57.3 +/- 36.8 months (6.0-161.0). The mean number of surgical procedures performed on one eye was 2.5 +/- 2.4 procedures (1-11). The mean IOP before the first surgery was 31.0 +/- 7.9 mmHg (17.5-52.0), and was 15.0 +/- 3.9 mmHg (7.0-28.0) at the last visit. 49 eyes (72.1%) did not need any further medical treatment after the last surgical procedure. The IOP was 18 mmHg or lower without medication in 29 eyes (42.6%) after just one surgical procedure (21 trabeculotomy, 8 combined trabeculotomy/trabeculectomy with or without mitomycin-C). At the first examination, the mean axial length of the eyeball was 22.6 +/- 1.8 mm (the mean normal value at this age is 20.3 +/- 0.7 mm), and was 24.4 +/- 2.0 mm at the last visit (the mean normal value at this age is 22.2 +/- 0.6 mm). The best corrected visual acuity at the last visit was 0.25 +/- 4.6 lines; the normal range of visual acuity at this age is from 0.4 +/- 4.0 lines to 0.8 +/- 3.0 lines. Visual acuity was 0.32 or more in 53.0% of the eyes. Visual acuity was lower than 0.1 in only 15.2% of the eyes. Myopia was present in 57.4% of the eyes with a mean spherical equivalent of -6.1 +/-3.9 dioptres. 15 patients (34.9%) developed strabismus. 22 patients (51.2%) were treated with part-time occlusion. Binocular function as assessed with the Lang-1 test was positive in 17 of 30 patients (56.7%). CONCLUSIONS: Although a good long-term IOP-control can often be achieved in childhood glaucoma, the visual acuity remains below the normal range in most cases despite close orthoptic follow-up.