BACKGROUND: Disconjugate eye movements are essential for depth perception in frontal-eyed species, but their underlying neural substrates are largely unknown. Lesions in the midbrain can cause disconjugate eye movements. While vertically disconjugate eye movements have been linked to defective visuo-vestibular integration, the pathophysiology and neuroanatomy of horizontally disconjugate eye movements remains elusive.
METHODS: A patient with a solitary focal midbrain lesion was examined using detailed clinical ocular motor assessments, binocular videooculography and diffusion-weighted MRI, which was co-registered to a high-resolution cytoarchitectonic MR-atlas.
RESULTS: The patient exhibited both vertically and horizontally disconjugate eye alignment and nystagmus. Binocular videooculography showed a strong correlation of vertical and horizontal oscillations during fixation but not in darkness. Oscillation intensities and waveforms were modulated by fixation, illumination, and gaze position, suggesting shared visual- and vestibular-related mechanisms. The lesion was mapped to a functionally ill-defined area of the dorsal midbrain, adjacent to the posterior commissure and sparing nuclei with known roles in vertical gaze control.
CONCLUSIONS: A circumscribed region in the dorsal midbrain appears to be a key node for disconjugate eye movements in both vertical and horizontal planes. Lesioning this area produces a unique ocular motor syndrome mirroring hallmarks of developmental strabismus and nystagmus. Further circuit-level studies could offer pivotal insights into shared pathomechanisms of acquired and developmental disorders affecting eye alignment.

Amblyopia is a developmental visual disorder resulting from atypical binocular experience in early childhood that leads to abnormal visual cortex development and vision impairment. Recovery from amblyopia requires significant visual cortex neuroplasticity, i.e. the ability of the central nervous system and its synaptic connections to adapt their structure and function. There is a high level of neuroplasticity in early development and, historically, neuroplastic responses to changes in visual experience were thought to be restricted to a \"critical period\" in early life. However, as our review now shows, the evidence is growing that plasticity of the adult visual system can also be harnessed to improve vision in amblyopia. Amblyopia treatment involves correcting refractive error to ensure clear and equal retinal image formation in both eyes, then, if necessary, promoting the use of the amblyopic eye by hindering or reducing visual input from the better eye through patching or pharmacologic therapy. Early treatment in children can lead to visual acuity gains and the development of binocular vision in some cases; however, many children do not respond to treatment, and many adults with amblyopia have historically been untreated or undertreated. Here we review the current evidence on how dichoptic training can be used as a novel binocular therapeutic approach to facilitate visual processing of input from the amblyopic eye and can simultaneously engage both eyes in a training task that requires binocular integration. It is a novel and promising treatment for amblyopia in both children and adults.

BACKGROUND: Eye movement abnormalities are commonplace in neurological disorders. However, unaided eye movement assessments lack granularity. Although videooculography (VOG) improves diagnostic accuracy, resource intensiveness precludes its broad use. To bridge this care gap, we here validate a framework for smartphone video-based nystagmography capitalizing on recent computer vision advances.
METHODS: A convolutional neural network was fine-tuned for pupil tracking using > 550 annotated frames: ConVNG. In a cross-sectional approach, slow-phase velocity of optokinetic nystagmus was calculated in 10 subjects using ConVNG and VOG. Equivalence of accuracy and precision was assessed using the \"two one-sample t-test\" (TOST) and Bayesian interval-null approaches. ConVNG was systematically compared to OpenFace and MediaPipe as computer vision (CV) benchmarks for gaze estimation.
RESULTS: ConVNG tracking accuracy reached 9-15% of an average pupil diameter. In a fully independent clinical video dataset, ConVNG robustly detected pupil keypoints (median prediction confidence 0.85). SPV measurement accuracy was equivalent to VOG (TOST p < 0.017; Bayes factors (BF) > 24). ConVNG, but not MediaPipe, achieved equivalence to VOG in all SPV calculations. Median precision was 0.30°/s for ConVNG, 0.7°/s for MediaPipe and 0.12°/s for VOG. ConVNG precision was significantly higher than MediaPipe in vertical planes, but both algorithms\' precision was inferior to VOG.
CONCLUSIONS: ConVNG enables offline smartphone video nystagmography with an accuracy comparable to VOG and significantly higher precision than MediaPipe, a benchmark computer vision application for gaze estimation. This serves as a blueprint for highly accessible tools with potential to accelerate progress toward precise and personalized Medicine.

BACKGROUND: Impaired vision is one of the commonest and most disabling consequence following stroke. Among all visual impairments, eye movement disorders are found in 70% of stroke patients which include nystagmus, strabismus, gaze palsies, disconjugate eye movements and cranial nerve palsies. They have a wide ranging impact on balance and activities of daily livings by creating difficulties in maintaining normal alignment and appropriate movement of eyes. The purpose of this study was to examine the effects of visual scanning exercises in addition to task specific approach on balance and activities of daily livings in post stroke patients with eye movement disorders.
METHODS: This study is a randomized controlled trial and was conducted in the University of Lahore Teaching Hospital from May 2019 to October 2020. A sample of 64 patients was recruited and randomly allocated into experimental and control group. 32 patients in experimental group were treated with visual scanning exercises along with task specific approach and 32 patients in control group were treated with task specific approach alone. Pre and post assessment of balance and activities of daily livings was assessed on BERG BALANCE SCALE and BARTHEL INDEX SCALE at baseline and at 4th week.
RESULTS: Intra-group analysis of BERG BALANCE SCALE in experimental group showed statistically significant result (p < 0.05) in all items except in items 4, 13 and 14 respectively. Intra-group analysis of BERG BALANCE SCALE in control group showed statistically significant result (p < 0.05) in items 3, 5, 8 and 12 respectively, whereas remaining all items showed statistically insignificant result. Intra-group analysis of BARTHEL INDEX SCALE in experimental group showed statistically significant result in all items (p < 0.05) except in items 9 and 10 respectively. Intra-group analysis of BARTHEL INDEX in control group showed statistically significant result (p < 0.05) in items 1, 3, 4 and 8 respectively whereas remaining all items showed statistically insignificant result. Inter-group analysis showed statistically significant result in total scores of BERG BALANCE SCALE (p = 0.000) and BARTHEL INEX SCALE (p = 0.033).
CONCLUSIONS: Visual scanning exercises along with task specific approach were found to be more effective in comparison to task specific approach alone.
BACKGROUND: Trial registration number: [IRCT20190717044237N1], trial registration date: 10/11/2019.

Clinical diagnosis of Parkinsonism is still challenging, and the diagnostic biomarkers of Multiple System Atrophy (MSA) are scarce. This study aimed to investigate the diagnostic value of the combined eye movement tests in patients with Parkinson\'s disease (PD) and those with MSA.
We enrolled 96 PD patients, 33 MSA patients (18 with MSA-P and 15 with MSA-C), and 40 healthy controls who had their horizontal ocular movements measured. The multiple-step pattern of memory-guided saccade (MGS), the hypometria/hypermetria of the reflexive saccade, the abnormal saccade in smooth pursuit movement (SPM), gaze-evoked nystagmus, and square-wave jerks in gaze-holding test were qualitatively analyzed. The reflexive saccadic parameters and gain of SPM were also quantitatively analyzed.
The MGS test showed that patients with either diagnosis had a significantly higher incidence of multiple-step pattern compared with controls (68.6%, 65.2%, and versus. 2.5%, p < .05, in PD, MSA, versus. controls, respectively). The reflexive saccade test showed that MSA patients showing a prominent higher incidence of the abnormal saccade (63.6%, both hypometria and hypermetria) than that of PD patients and controls (33.3%, 7.5%, respectively, hypometria) (p < .05). The SPM test showed PD patients had mildly decreased gain among whom 28.1% presenting \"saccade intrusions\"; and that MSA patients had the significant decreased gain with 51.5% presenting \"catch-up saccades\"(p < .05). Only MSA patients showed gaze-evoked nystagmus (24.2%), square-wave jerks (6.1%) in gaze-holding test (p < .05).
A panel of eye movements tests may help to differentiate PD from MSA. The combined presence of hypometria and hypermetria in saccadic eye movement, the impaired gain of smooth pursuit movement with \"catch-up saccades,\" gaze-evoked nystagmus, square-wave jerks in gaze-holding test, and multiple-step pattern in MGS may provide clues to the diagnosis of MSA.

OBJECTIVE: The purpose of this retrospective cohort study was to report the outcomes of high AC/A ratio accommodative esotropia (AET) among children.
METHODS: The medical records of all children <19 years diagnosed with accommodative esotropia and a high AC/A ratio while residing in Olmsted County, Minnesota, from January 1, 1975, through December 31, 2004, were retrospectively reviewed.
RESULTS: A total of 512 patients were diagnosed with AET during the 30-year study period, of which 395 (77.1%) had fully accommodative ET, 117 (22.8%) had partially accommodative ET and 106 (20.5%) had a high AC/A ratio. Of the 93 (87.7 %) high AC/A patients managed with bifocals, 50 (53.8 %) discontinued their use after a mean of 58.7 (range: 5.6-229) months. The Kaplan-Meier rate of discontinuing bifocals was 24.5% at 3 years, 36.4% at 5 years, and 61.4% at 10 years. Patients who discontinued bifocals were more likely to have had strabismus surgery (44% vs 18.6%, p = 0.009) than those who did not discontinue bifocals. The high AC/A patients managed with bifocals achieved similar stereoacuity outcomes to those who did not wear bifocals (p = 0.65) and were no more likely to require surgery (p = 0.13).
CONCLUSIONS: Among this cohort of children with accommodative esotropia and a high AC/A ratio, bifocal use was discontinued in the majority of children within 10 years, and more commonly among those who underwent strabismus surgery. The use of bifocals was not associated with a higher likelihood of undergoing surgery or enhanced stereopsis compared to those who did not use them.

UNASSIGNED: To evaluate the efficacy and safety of peribulbar anesthesia during strabismus surgery.
UNASSIGNED: Medical records of patients undergoing strabismus surgery and peribulbar anesthesia were reviewed. The overall efficacy of peribulbar anesthesia was evaluated as requirement of supplemental peribulbar anesthesia, impossibility to perform eye muscles surgery due to inadequate efficacy of the block and peribulbar block complications that occurred up to 6 weeks postoperatively. Presence of oculocardiac reflex (OCR) and presence of decreased visual acuity and afferent pupillary defect postoperatively were reported.
UNASSIGNED: A total of 510 patients comprised our study group. The total amount of peribulbar injections was 717. Four patients (0.7%) required supplemental injection in the superonasal quadrant. Five of 510 (0.9%) required an anesthesiologic intervention with intravenous atropine. Eighty patients of 510 (15.6%) complained about transitory complete ptosis and/or amaurosis postoperatively. No complications were observed up to 6 weeks postoperatively.
UNASSIGNED: Peribulbar anesthesia was an effective and safe option during strabismus surgery in adult patients.

UNASSIGNED: To evaluate the efficacy of symmetric bilateral medial rectus recession in large-angle esotropic Duane retraction syndrome (DRS) with moderate to severe globe retraction.
UNASSIGNED: In a retrospective study, medical reports of 30 patients with esotropia of equal or more than 20 prism diopters (pd) and moderate to serve globe retraction due to unilateral DRS who underwent symmetric bilateral medial rectus recession were reviewed. Age, gender, laterality, amblyopia, length of follow-up, pre- and postoperative measurements of primary position deviation, ocular ductions and severity of globe retraction and abnormal head posture were evaluated. A successful result was defined as decreasing esotropia to equal or less than 8 pd or equal or less than 8 pd of consecutive exotropia.
UNASSIGNED: The mean age of patients at surgery was 13.7 ± 8.5 years old (range: 3-38). The mean preoperative esotropia measured 28.9 ± 9.1 pd in distance and 25.7 ± 7.2 pd in near, which decreased to 4.9 ± 6.1 pd in distance and 3.9 ± 8.8 pd in near postoperatively. The mean bilateral medial rectus recession was 4.9 ± 0.9 mm (range: 3-6 mm). The mean abnormal head posture improved from 19.1 ± 6.9 degrees (range: 10-30 degrees) to 3.3 ± 4.7 degrees (range: 0-15 degrees) postoperatively. At the last follow-up visit, 23 patients (76.7%) had a successful outcome.
UNASSIGNED: In the large-angle esotropic DRS patients with moderate to severe globe retraction, symmetric bilateral medial rectus recession, can be conducted to successfully resolve primary position deviation and abnormal head posture.

Ocular neuromyotonia (ONM) is characterized by episodes of binocular diplopia usually triggered by an eye movement requiring contraction of the affected extraocular muscle. It consists of an involuntary, sometimes painful contraction of one or more extraocular muscles. It is most often secondary to radiotherapy of the para-sellar region, although other aetiologies have been reported. Some cases do not have a clearly identified aetiology and are classified as idiopathic. Most cases of ONMs are unilateral but bilateral ONMs have also been described.1-4 We report a case of left ONM in a 55-year-old female patient, several weeks after simultaneous surgical resection of two meningiomas, situated on the right side (Simpson II). The particularity of this case is linked to its puzzling presentation, its similarity with spasm of the near reflex and the putative mechanism through which surgery might have precipitated the symptoms.

UNASSIGNED: To investigate how a subset of patients with partially accommodative esotropia, with a manifest deviation <10 Prism Diopters (PD) at distance and an angle of strabismus at near wider than 10 PD, could respond to a surgical approach based on the misalignment at near.
UNASSIGNED: Six patients examined from 2015 to 2019 met criteria for inclusion: partially accommodative esotropia, patients compliant to full correction for at least 6 months, angle of esotropia for near larger at least 10 PD, angle of misalignment obtained with the alternate prism cover test and simultaneous prism cover test at distance <10 PD. All patients underwent bilateral medial recti recession. They were examined at 3 weeks and at 6 months.
UNASSIGNED: No significant difference in the angle of esotropia at distance was found at any follow-up (Baseline: 7.17 ± 1.33 PD vs 3 weeks: 7.0 ± 1.01 PD vs 6 months: 7.33 ± 1.03 PD, p = 0.65, and p = 0.36, respectively). No case of consecutive exotropia was described. Considering the angle at near, there was a significant reduction at 3 weeks (Baseline: 41.7 ± 6.83 PD vs 3 weeks: 9.33 ± 1.63 PD, p = 0.027), that remained stable at the final follow-up (9.0 ± 1.1 PD, p = 0.32). All patients were suppressors and had nil stereopsis pre-operatively, all of them developed fusion and a different degree of stereopsis [276 ± 284 arcseconds (Range 80-800)].
UNASSIGNED: A surgical approach based on the angle of strabismus for near could obtain satisfactory ocular alignment without consecutive exotropia in children with partially accommodative esotropia wearing full refractive correction, with a manifest deviation for distance <10 PD and a higher misalignment for near, at least for 6 months after surgery.