Alteration Ocular Motility in Retinitis Pigmentosa: Case-Control Study

Purpose

To evaluate ocular motility (OM) disorders and strabismus in a sample of patients with retinitis pigmentosa (RP) and a control sample.

Methods

In this cross-sectional retrospective analysis, we studied a sample of RP patients with a mean age of 48.74 years and an average visual acuity of 7/10 based on Snellen optotype and a sample of control patients with similar mean age (49 years [men], 47 years [women]) and sex and an average visual acuity of 9.9/10, with the aim of assessing correlations between alteration of OM and strabismus in RP patients based on age, high refractive defect, or severely impaired binocular vision. The examination followed a protocol of testing for anamnesis and best-corrected visual acuity, as well as a complete eye examination, corneal reflex, cover test, OM, Hess screen, and Lang test.

Results

At the first orthoptic evaluation, 45.16% of patients showed strabismus, 41.93% exotropia (25% of cases intermittent), 3.22% esotropia, and 6.45% vertical deviation. Later evaluation showed strabismus in 25.80% of patients, exotropia in 19.35% (9.67% intermittent), esotropia in 3.22%, and vertical deviation in 3.22%. Assessment of eye motility study showed 51.6% overaction of the inferior oblique and hypofunction of the superior rectus, and 18% overaction of the lateral rectus and hypofunction of the medial rectus. According to our results, alterations in OM and strabismus in RP patients are not correlated with age or high refractive defect. Therefore, motility disorders and strabismus are attributed to a genetic factor to which men are more susceptible.

Conclusion

The incidence of OM disorder was 77.42%, and strabismus was present in 45.16% of patients.

Ocular Motility Patterns in Intellectual Disability: Insights from the Developmental Eye Movement Test

PURPOSE

To measure the ocular motility parameters of the Developmental Eye Movement (DEM) test objectively, with an eye tracker in subjects with intellectual disability (ID).

METHODS

The DEM test was performed on 45 subjects with ID, while their eye movements were recorded with an eye tracker. Some objective parameters of ocular motility were obtained through each subtest (A, B, and C) of the full DEM test.

RESULTS

There was a significant positive correlation between the saccadic speed (cc: 0.537; p = 0.001) and length (cc: 0.368; p = 0.030) of both eyes for the same subject. People with a higher percentage of ID exhibited a greater number of fixations, saccades, and errors, and took longer to perform the DEM test than those with a lower ID percentage, who had greater numbers of these parameters than subjects without ID. Subjects without ID exhibited faster saccades, with a higher amplitude, than subjects with ID.

CONCLUSIONS

The eye tracker quantifies ocular motility parameters involved in the DEM test in subjects with ID. Both eyes' movements in subjects with ID were conjugated, exhibiting saccades of the same length and speed. All parameters were different in subjects with ID compared to those in subjects without ID, so normative tables specifically for subjects with ID are necessary.

Deep Learning Model for Static Ocular Torsion Detection Using Synthetically Generated Fundus Images

Purpose

The objective of the study is to develop deep learning models using synthetic fundus images to assess the direction (intorsion versus extorsion) and amount (physiologic versus pathologic) of static ocular torsion. Static ocular torsion assessment is an important clinical tool for classifying vertical ocular misalignment; however, current methods are time-intensive with steep learning curves for frontline providers.

Methods

We used a dataset (n = 276) of right eye fundus images. The disc-foveal angle was calculated using ImageJ to generate synthetic images via image rotation. Using synthetic datasets (n = 12,740 images per model) and transfer learning (the reuse of a pretrained deep learning model on a new task), we developed a binary classifier (intorsion versus extorsion) and a multiclass classifier (physiologic versus pathologic intorsion and extorsion). Model performance was evaluated on unseen synthetic and nonsynthetic data.

Results

On the synthetic dataset, the binary classifier had an accuracy and area under the receiver operating characteristic curve (AUROC) of 0.92 and 0.98, respectively, whereas the multiclass classifier had an accuracy and AUROC of 0.77 and 0.94, respectively. The binary classifier generalized well on the nonsynthetic data (accuracy = 0.94; AUROC = 1.00).

Conclusions

The direction of static ocular torsion can be detected from synthetic fundus images using deep learning methods, which is key to differentiate between vestibular misalignment (skew deviation) and ocular muscle misalignment (superior oblique palsies).

Translational Relevance

Given the robust performance of our models on real fundus images, similar strategies can be adopted for deep learning research in rare neuro-ophthalmologic diseases with limited datasets.

Effectiveness of diagnosis and early treatment of ocular motility alterations in premature infants

Objective

Prematurity often results in important developmental sequelae of brain structures, particularly those involved in processing visual information, such as the optic nerve, primary visual cortex and visuomotor integration areas. The aim of this study is to analyse the functionality of the sensory and motor pathways of the visual system by means of an orthoptic-ophthalmological assessment.

Materials and methods

In this retrospective study, 151 records were examined, covering a period from 2000 to 2020, of preterm patients with gestational age < 32 weeks and birth weight ≤ 1,500 g up to an average age of about 8 years, referred to the Centre for Paediatric Ophthalmology and Strabology of the Ophthalmology Clinic of the Policlinico Umberto I, La Sapienza University of Rome, who underwent a complete ophthalmological and orthoptic assessment including the following tests measurement of ocular deviations according to the Hirschberg method, Lang I-II test, Titmus Stereotest, objective convergence assessment and ocular motility examination.

Results

From the charts reviewed, 24.5% (37/151) of patients had Retinopathy of the Premature (ROP); while 38% of the whole sample (57/151) had strabismic amblyopia, of the latter only 31.5% (18/57) had ROP. In 8% of patients (12/151) the stereoscopic sense was absent, in 45% (8/151) stereopsis was gross (> 60 seconds of arc). In addition, 20.52 % (31/151) had a manifest eye deviation. 7.28% (11/151) had hypermetropia in the right eye (RE); 7.95% (12/151) hypermetropia in the left eye (OS); 3.31% of the patients (5/151) had myopia in the RE; 2% (3/151), myopia in the left eye (LE). In addition, the study of ocular motility revealed varying degrees of alteration poorly correlated with prematurity status.

Conclusion

It was found that amblyopia, stereopsis and objective convergence are more affected by ROP than strabismus, refractive defects and ocular motility, indicating that premature children are particularly susceptible to ophthalmological and orthoptical alterations.

Early Intervention in Orbital Floor Fractures: Postoperative Ocular Motility and Diplopia Outcomes

Purpose: Orbital floor fractures commonly occur during orbital trauma. Currently, the indications for orbital fracture repair and the appropriate duration between trauma and surgical intervention remain controversial. Methods: Eyes diagnosed with orbital floor fractures that underwent reconstruction surgery were retrospectively reviewed. Demographic data were analyzed. Patients were classified based on the timing of the surgical intervention after injury. Ocular limitation and diplopia were evaluated preoperatively and postoperatively at one week, one month, and three months. Results: Two hundred seventy eyes of 270 patients (174 males and 96 females, mean age: 40.9 ± 16.3 years) were identified. The mean duration from injury to surgical intervention was 18.0 ± 21.2 days (range: 0−117 days). In the subgroup analysis, compared to delayed treatment, the early repair of floor fractures, i.e., within 7 days, was associated with significant motility and diplopia resolution at one week (p = 0.001, p < 0.001), one month (p < 0.001, p < 0.001), and three months (p < 0.001, p < 0.001). Sex and the duration from injury to repair were significantly associated with postoperative ocular motility (p = 0.001; p = 0.024) and diplopia (p < 0.001; p = 0.008) at three months. Multivariate analysis revealed that preoperative limitation and diplopia were correlated with postoperative limitation (p = 0.007) and diplopia (p = 0.001), respectively. Conclusions: The duration between orbital floor fracture and surgical treatment was associated with postoperative limitation and diplopia. Our results suggest that earlier intervention in symptomatic patients with orbital trauma may improve postoperative visual function.

Outcomes and risk factors of surgical management of thyroid eye disease-related diplopia

OBJECTIVES

To evaluate the outcomes of strabismus surgery in patients with thyroid eye disease (TED) and to assess the influence of preceding treatments such as steroid administration, orbital decompression and radiotherapy.

METHODS

Retrospective study on a cohort of patients with TED undergoing strabismus surgery. Data collection included clinical features, smoking status, preceding steroid therapy, orbital radiation therapy and orbital decompression. Qualitative evaluation, assessing diplopia and quality of life and quantitative evaluation, assessing the eye misalignment were analysed 1 year after the last squint surgical procedure.

RESULTS

Seventy-nine patients were identified. Ninety-five surgical procedures were performed on 92 eyes. A significant overall improvement of ocular motility was registered (p < 0.001, paired t-test). Forty-five (57%) patients had excellent outcomes, twenty-three (29%) had good outcomes and eleven (14%) had poor outcomes. The average number of muscles operated was significantly greater in patients who underwent orbital bone decompression (1.58 ± 0.63; p = 0.0082; 95% CI 1.413-10.214). Quantitative and qualitative outcomes were not associated with the preceding therapy: steroid (p = 0.75), radiotherapy (p = 0.95) or orbital bone decompression (p = 0.25). The success rate was no different between adjustable and fixed sutures (p = 0.8).

CONCLUSION

Strabismus surgery in TED patients resulted in a high success rate in reducing diplopia and improving ocular motility. The success rate was not negatively associated with previous therapies. Indeed, resolution of diplopia required more squint procedures in patients who have previously undergone to orbital decompression.

Role of orthoptics and scoring system for orbital floor blowout fracture: surgical or conservative treatment

AIM

To assess the role of orthoptics in referring patients with orbital floor blowout fracture (OFBF) for conservative or surgical treatment and based on the results, to propose a scoring system for such decision making.

METHODS

A retrospective analysis of 69 patients with OFBF was performed (35 treated conservatively, 34 surgically). The role of orthoptics in referring to surgery or conservative treatment was retrospectively evaluated, the factors with the highest significance for decision making were identified, and a scoring system proposed using Logistic regression.

RESULTS

According to defined criteria, the treatment was unsuccessful in 2 (6%) surgically treated and only in one (3%) conservatively treated patient. The proposed scoring system includes the defect size and several values resulting from the orthoptic examination, the elevation of the eyebulb measured on Lancaster screen being the most significant.

CONCLUSION

The study demonstrates the benefits of orthoptic examination when making decisions on conservative or surgical treatment and for diagnosing ocular motility disorder (with or without binocular diplopia) in OFBF patients. The proposed scoring system could, following verification in a prospective study, become a valuable adjunctive tool.

Utility of Ocular Motility Tests in Orbital Floor Fractures with Muscle Entrapment That is Not Detected on Computed Tomography

Purpose

Determine the usefulness of ocular motility testing to detect the presence of muscle entrapment.

Materials and Methods

Cross-sectional study of patients with symptoms of diplopia secondary to facial trauma. Inclusion criteria: age between 20 and 80 years; symptoms of diplopia following facial trauma; presence of orbital floor fracture confirmed radiologically; presence of muscle entrapment confirmed at the time of surgery; best-corrected visual acuity of 0.6 or more. Exclusion criteria: muscle entrapment visible on computed tomography; candidate for immediate surgical correction; prior history of strabismus surgery. Outcome measures: Abnormal Head Position (AHP), Hirschberg Corneal Reflexes (CR), Cover/Uncover and Alternating Cover Test, Hertel exophthalmometry, Near Point of Convergence (NPC), Kestenbaum Limbus test, Red Filter test, and Hess screen test.

Results

Forty-six subjects (38 males, 8 females, mean age 27 ± 3.3 SD years). Pre-operative assessment: forty-six (100%) reported diplopia on the Red Filter test and showed some degree of abnormality on the Hess Screen test. Forty-two (91%) showed AHP. Forty-one (89%) had exophthalmometry values that differed 2 mm or more between the two eyes and insufficient NPC. Thirty-two (69.6%) showed deficits of 3 mm or more on the Kestenbaum Limbus test. Sixteen (35%) had abnormal Hirschberg corneal reflexes. Eleven (24%) demonstrated constant or intermittent strabismus.

Conclusion

Ocular motility testing can differentiate non-invasively, pre-operatively, and cost-effectively the presence of muscle entrapment even when this is not visible on computed tomography.

Ocular Involvement Occurs Frequently at All Stages of Amyotrophic Lateral Sclerosis: Preliminary Experience in a Large Italian Cohort

Background and Purpose

The study aimed to obtain optometric findings of amyotrophic lateral sclerosis (ALS) patients in different stages of the disease, and to determine the relation between ocular data and ALS-related features; that is, functional and cognitive impairment and staging.

Methods

The optometric protocol included tests of the ocular motility [broad-H test and Northeastern State University College of Optometry (NSUCO) test], near point of convergence (NPC), error refraction, best-corrected visual acuity, and binocular visual alignment, and an ocular symptoms questionnaire. The functional measures included the Amyotrophic Lateral Sclerosis Functional Rating Scale–revised (ALSFRS-r) and Milano-Torino staging (MiToS), and cognitive impairment was assessed using the Edinburgh Cognitive and Behavioural ALS Screen (ECAS). Demographic and clinical features were also collected, including whether the patients used an eye-tracking communication device (ETCD).

Results

Two-hundred consecutive ALS patients (median age of 64 years, 118 males and 82 females) in different stages of disease were recruited. Nearly 70% of patients reported at least one ocular symptom, and the use of an ETCD was found to be significantly related to the presence of most symptoms. Moreover, the severely symptomatic group was characterized by significantly lower ALSFRS-r total and subscale scores, and higher MiToS. Abnormal NPC values were significantly related to lower ALSFRS-r total and bulbar-subscale scores. Patients with acceptable NSUCO test values exhibited significantly higher ECAS scores.

Conclusions

The presence of ocular alteration in patients in different stages of ALS supports the idea that this is a multisystem disorder and emphasizes the importance of optometric evaluations in multidisciplinary assessments to address ocular impairment early in the disease process.

Spontaneous, isolated, and gaze-evoked ocular flutter: A rare case report

This case illustrates the need to correctly identify oscillopsia among cases of self-reported dizziness, and ocular flutter itself as a presenting sign of potentially serious underlying disease. The neurologist should approach these patients in a systematic manner, in order to exclude concurrent or impending comorbidities such as neoplastic disease.

Acquired Synergistic Divergence: Contrary to Current Literature

Current literature reports synergistic divergence as a rare, congenital ocular motility pattern associated with adduction palsy. Its mechanism has been likened to Duane's syndrome, and some suggest it be referred to as Duane's Type 4 (Gupta et al. 2010; Schliesser et al. 2016; Wilcox et al. 1981; Khan et al. 2016). There are no published reports of synergistic divergence as an acquired condition, making this case report seemingly the first of its kind. This case report describes an 18-year-old female who presented to clinic in 2013 with symptoms of diplopia and left eye turning outwards. Orthoptic assessment and MRI confirmed a third nerve palsy secondary to cavernous sinus schwannoma. Further monitoring showed progression of the cranial nerve palsy but a stable schwannoma and no aberrant regeneration noted in five years of follow up. The patient was treated with multiple botulinum toxin injections and had squint correction surgery in 2017. Seven months later, synergistic divergence was first noted and remained stable in all following assessments. While the aetiology of acquired synergistic divergence in this case is unclear, we can be confident it is unlikely to be of congenital origin as it was not noted until adulthood and after five years of investigations. This report will discuss possible aetiologies of acquired synergistic divergence and, contrary to current literature, suggest clinicians should consider the possibility that synergistic divergence can be acquired, though is likely to be even rarer than its congenital form.

Diagnosis and surgical management of isolated inferior oblique palsy

AIM

To describe the etiology, clinical characteristics, surgical options and surgical outcomes of isolated inferior oblique palsy (IOP).

METHODS

A retrospective review was performed on patients with isolated IOP who were seen between January 2010 and June 2017. The following clinical data were obtained from the patients' charts: visual acuity, ocular alignment, ocular motility, cyclotorsion, stereoacuity, Parks three-step test, surgical methods, surgical outcomes and complications. Surgical success was defined as horizontal deviation ≤10 prism diopters (PD) and a vertical deviation ≤5 PD in primary gaze at both near and distant vision as assessed at last follow-up.

RESULTS

The records from a total of 18 patients (8 males and 10 females) with an average age of 27.56y were included in this study. The right eye was affected in 11 patients, the left in 6 patients and both eyes in 1 patient. Twelve cases (66.7%) were congenital and 6 (33.3%) were acquired IOP. The 6 acquired cases involved 2 resulting from orbital trauma/surgery, 2 from midbrain microvascular ischemia, 1 from myasthenia gravis and 1 of unknown etiology. Strabismus surgery was performed in 13 cases. Surgical techniques included weakening of superior oblique and vertical rectus recession and resection. After a mean follow-up of 15.11mo, the corrected vertical deviation in primary position was 19.92±8.52 PD (P=0.000) and the corrected horizontal deviation was 14.31±12.68 PD (P=0.002). The surgical success rate was 61.5% and no surgical complications were present.

CONCLUSION

Isolated IOP represents a rare condition, with most cases (66.7%) involving a congenital basis. The acquired cases included vascular, orbital trauma/surgery and myasthenia gravis. Weakening of the ipsilateral superior oblique muscle and/or contralateral superior rectus recession often resulted in favorable surgical outcomes with a surgical success rate of 61.5%.

Co-occurrence of Convergence Insufficiency and Cognitive Impairment in Parkinsonian Disorders: A Pilot Study

Background: Convergence insufficiency (CI) in parkinsonian conditions causes disabling visual symptoms during near tasks and usually manifests as double vision. Since double vision is more common in patients who report cognitive symptoms, we sought to determine if symptomatic CI, as opposed to asymptomatic CI, could serve as a marker of cognitive impairment in parkinsonian disorders. Methods: Twenty-four participants with parkinsonian disorders (18 Parkinson's disease, 5 progressive supranuclear palsy, 1 multiple system atrophy) and objective findings of convergence insufficiency on neuro-ophthalmologic examination were included. Subjective visual symptoms and cognitive complaints were recorded, and the Self-Administered Gerocognitive Examination was used as a global cognitive screening measure. Results: 54.1% of parkinsonian participants had cognitive impairment, but there were no significant differences in the degree of convergence insufficiency, measured by near point of convergence (NPC), or cognitive outcomes between those with symptomatic CI, and asymptomatic CI. However, NPC was greater for those with cognitive impairment (x = 18.4 cm), compared to those who were cognitively intact (x = 12.5 cm, p = 0.003). Conclusions: Cognitive impairment commonly co-occurs in parkinsonian disorders with convergence insufficiency and is associated with significantly greater NPC distances. Clinicians should have a high index of suspicion for cognitive impairment in patients with objective findings of convergence insufficiency, whether symptomatic or not. Further investigation of convergence insufficiency in relationship to cognitive impairment in parkinsonian disorders is warranted, as there may be a shared mechanism of dysfunction.

Deficits in saccades and smooth-pursuit eye movements in adults with traumatic brain injury: a systematic review and meta-analysis

PURPOSE

To conduct a review of literature and quantify the effect that traumatic brain injury (TBI) has on oculomotor functions (OM).

METHODS

A systematic review and meta-analysis was conducted from papers that objectively measured saccades and smooth-pursuit eye movements in mild and severe TBI.

RESULTS

The overall impact of TBI on OM functions was moderate and significant with an effect size of 0.42 from 181 OM case-control comparisons. The heterogeneity, determined using the random effect model, was found to be significant (Q (180) = 367, p < 0.0001, I² = 51) owing to the variety of OM functions (reflexive saccades, antisaccades, memory-guided saccades, self-paced saccades and pursuits) measured and varying post-injury periods.The overall effect on OM functions were similar in mild and severe TBI despite differences in combined effect size of various OM functions. OM functions involving complex cognitive skills such as antisaccades (in mild and severe TBI) and memory-guided saccades (in mild TBI) were the most adversely affected, suggesting that OM deficits may be associated with cognitive deficits in TBI.

CONCLUSION

TBI often results in long-standing OM deficits. Experimental measures of OM assessment reflect neural integrity and may provide a sensitive and objective biomarker to detect OM deficits following TBI.

Oculomotor and Vestibular Findings in Gaucher Disease Type 3 and Their Correlation with Neurological Findings

Objectives

To evaluate the function of the oculomotor and vestibular systems and to correlate these findings with the clinical status of patients with Gaucher disease type 3 (GD3). The goal of this cross-sectional and longitudinal study was to find oculomotor biomarkers for future clinical trials.

Methods

Twenty-six patients with GD3 were assessed for eligibility and 21 were able to perform at least one task. Horizontal and vertical reflexive saccades, smooth pursuit, gaze-holding, optokinetic nystagmus, and horizontal vestibulo-ocular reflex (VOR) were examined by video-oculography/video-head impulse test and compared concurrently with 33 healthy controls. The Scale for the Assessment and Rating of Ataxia (SARA), the modified Severity Scoring Tool (mSST), and Grooved Pegboard Test (GPT) were administered to assess overall neurological function. Eleven patients were also re-assessed after 1 year.

Results

Nine out of 17 patients exhibited gaze-holding deficits. One patient had upbeat nystagmus. Three patients presented with bilateral abducens palsy in combination with central oculomotor disorders, suggesting a bilateral involvement of the abducens nucleus. Horizontal angular VOR gain was reduced in all patients (0.66 ± 0.37) compared with controls (1.1 ± 0.11, p < 0.001). Most strongly correlated with clinical rating scales were peak velocity of downward saccades (SARA: ρ = −0.752, p < 0.0005; mSST: ρ = −0.611, p = 0.003; GPT: ρ = −0.649, p = 0.005) and duration of vertical saccades (SARA: ρ = 0.806, p < 0.001; mSST: ρ = 0.700, p < 0.0005; GPT: ρ = 0.558, p = 0.02) together with the VOR gain (SARA: ρ = −0.63, p = 0.016; mSST: ρ = −0.725, p = 0.003; GPT: ρ = −0.666, p = 0.004). Vertical smooth pursuit gain decreased significantly at follow-up.

Interpretation

This study shows neuronal degeneration of the brainstem and cerebellum with combined involvement of both supranuclear and nuclear oculomotor structures and the vestibular system in GD3. We also identified oculomotor parameters that correlate with the neurological status and can be used as biomarkers in future clinical trials.

The use of choline in association with the Bangerter filters for the treatment of amblyopia

The study investigated the effects of choline combined with Bangerter filter in the treatment of amblyopia. All amblyopic subjects used a Bangerter filter on the corrective spectacle lens (1d over the left eye, 1d over the right eye). Choline was then administered orally to 39 patients once daily, five days per week for the entire study period. Subjects treated with the Bangerter filter showed a mean visual acuity of 0.27 logMAR; at 12mo of treatment, the mean visual acuity reached 0.09 logMAR. Patients treated with the Bangerter filter and citicoline showed a mean visual acuity of 0.35 logMAR; at 12mo of treatment, the mean visual acuity reached 0.01 logMAR. No significant changes in the angle of deviation were observed in both groups. Subjects in both forms of amblyopia therapies demonstrated an increase in visual acuity. However, these effects were markedly enhanced when coupled with the administration of choline. Findings suggest that the effects are particularly relevant in the more severe amblyopic cases.

Vision In Stroke cohort: Profile overview of visual impairment

AIM

To profile the full range of visual disorders from a large prospective observation study of stroke survivors referred by stroke multidisciplinary teams to orthoptic services with suspected visual problems.

METHODS

Multicenter prospective study undertaken in 20 acute Trust hospitals. Standardized screening/referral forms and investigation forms documented data on referral signs and symptoms plus type and extent of visual impairment.

RESULTS

Of 1,345 patients referred with suspected visual impairment, 915 were recruited (59% men; mean age at stroke onset 69 years [SD 14]). Initial visual assessment was at median 22 days post stroke onset. Eight percent had normal visual assessment. Of 92% with confirmed visual impairment, 24% had reduced central visual acuity <0.3 logMAR and 13.5% <0.5 logMAR. Acquired strabismus was noted in 16% and acquired ocular motility disorders in 68%. Peripheral visual field loss was present in 52%, most commonly homonymous hemianopia. Fifteen percent had visual inattention and 4.6% had other visual perceptual disorders. Overall 84% were visually symptomatic with visual field loss the most common complaint followed by blurred vision, reading difficulty, and diplopia. Treatment options were provided to all with confirmed visual impairment. Targeted advice was most commonly provided along with refraction, prisms, and occlusion.

CONCLUSIONS

There are a wide range of visual disorders that occur following stroke and, frequently, with visual symptoms. There are equally a wide variety of treatment options available for these individuals. All stroke survivors require screening for visual impairment and warrant referral for specialist assessment and targeted treatment specific to the type of visual impairment.

Long-term therapeutic outcome of ophthalmic complications following endoscopic sinus surgery

Ophthalmic complications associated with endoscopic sinus surgery (ESS) are quite rare. There is a paucity of reliable data and limited experience on the clinical findings and treatments of these injuries. Our study here is to characterize the types of orbital injury following ESS, in particular extraocular muscle injury, and to evaluate the long-term therapeutic outcomes as compiled from a relatively large sample of Chinese patients.A series of 27 patients (21 males and 6 females; mean age = 42.6 years, ranges: 10-60 years) were retrospectively reviewed. The mean duration of orbital complication was 6.6 months (ranges: 1 day to 24 months). The right eye was affected in 19 patients and the left in 8 patients. All patients had various extraocular muscle dysfunction, including contusion, oculomotor nerve damage, muscle entrapment, muscle transection, and muscle destruction. All patients subjected to strabismus surgery showed an obvious reduction in deviation. Three patients achieved orthophoria without any surgery during the period of observation. All patients displayed mild to complicated orbital hemorrhage that often disappeared within 2 weeks. Optic nerve injury occurred in 29.6% of patients and vision damage in these patients was often irreversible.All patients with ophthalmic complications after ESS had strabismus and extraocular muscle dysfunction. Timing and type of strabismus surgery performed depended on the severity and number of muscles involved as well as the type of injury. This surgery is less effective in cases of restriction factor adhesion and/or entrapment as compared to that of patients with other types of strabismus. Orbital hemorrhages were usually resolved spontaneously, but optic nerve injury was mostly irreversible.

Visual and Vestibular Induced Eye Movements in Verbal Children and Adults with Autism

This study assessed the functionality of vestibular, pursuit, and saccade circuitry in autism across a wide age range. Subjects were 79 individuals with autism (AUT) and 62 controls (CON) aged 5 to 52 years with IQ scores > 70. For vestibular testing, earth-vertical axis rotation was performed in darkness and in a lighted visual surround with a fixation target. Ocular motor testing included assessment of horizontal saccades and horizontal smooth pursuit. No between-group differences were found in vestibular reflexes or in mean saccade velocity or accuracy. Saccade latency was increased in the AUT group with significant age-related effects in the 8-18 year old subgroups. There was a trend toward decreased pursuit gain without age effects. Normal vestibular-induced eye movements and normal saccade accuracy and velocity provide the most substantial evidence to date of the functional integrity of brainstem and cerebellar pathways in autism, suggesting that the histopathological abnormalities described in these structures may not be associated with intrinsic dysfunction but rather reflect developmental alterations related to forebrain cortical systems formation. Increased saccade latency with age effects adds to the extensive existing evidence of altered function and maturation of cortical systems in autism.

Ocular Neuromyotonia Associated with Chronic Inflammatory Demyelinating Polyneuropathy

Ocular neuromyotonia (ONM) is a neuro-ophthalmic disorder characterized by episodic diplopia caused by contraction of one or more ocular muscles due to spontaneous excitation of the respective ocular motor nerve. We report a patient whose ocular neuromyotonia arose in the setting of a subacute demyelinating polyneuropathy consistent with chronic inflammatory demyelinating polyneuropathy (CIDP) and subsequently resolved following the initiation of intravenous immunoglobulin (IVIg) for her neuropathy. Our patient provides additional evidence towards the role of demyelination and ephaptic neurotransmission in ocular neuromyotonia and also represents the first reported case of ocular neuromyotonia associated with a systemic neurological condition.

Eye tracking detects disconjugate eye movements associated with structural traumatic brain injury and concussion

Disconjugate eye movements have been associated with traumatic brain injury since ancient times. Ocular motility dysfunction may be present in up to 90% of patients with concussion or blast injury. We developed an algorithm for eye tracking in which the Cartesian coordinates of the right and left pupils are tracked over 200 sec and compared to each other as a subject watches a short film clip moving inside an aperture on a computer screen. We prospectively eye tracked 64 normal healthy noninjured control subjects and compared findings to 75 trauma subjects with either a positive head computed tomography (CT) scan (n=13), negative head CT (n=39), or nonhead injury (n=23) to determine whether eye tracking would reveal the disconjugate gaze associated with both structural brain injury and concussion. Tracking metrics were then correlated to the clinical concussion measure Sport Concussion Assessment Tool 3 (SCAT3) in trauma patients. Five out of five measures of horizontal disconjugacy were increased in positive and negative head CT patients relative to noninjured control subjects. Only one of five vertical disconjugacy measures was significantly increased in brain-injured patients relative to controls. Linear regression analysis of all 75 trauma patients demonstrated that three metrics for horizontal disconjugacy negatively correlated with SCAT3 symptom severity score and positively correlated with total Standardized Assessment of Concussion score. Abnormal eye-tracking metrics improved over time toward baseline in brain-injured subjects observed in follow-up. Eye tracking may help quantify the severity of ocular motility disruption associated with concussion and structural brain injury.

Slowed saccades and increased square wave jerks in essential tremor

BACKGROUND

Eye movements in essential tremor (ET) are poorly described and may present useful information on the underlying pathophysiology of the disorder.

METHODS

Sixty patients with ET, including 15 de novo untreated patients, and 60 age-matched controls constitute the study population. A video-based eye tracker was used to assess binocular eye position. Oculomotor function was assessed while subjects followed random horizontally and vertically step-displaced targets.

RESULTS

For all reflexive saccades, latencies were increased in ET subjects by a mean of 16.3% (p<0.01). Saccades showed reduced peak velocities with a lengthy, wavering velocity plateau, followed by slowed decelerations. For larger 30°+ saccades, peak velocities were decreased by a mean of 25.2% (p<0.01) and durations increased by 31.8% (p<0.01). The frequency of square wave jerks (SWJs) in patients was more than triple that of controls (p<0.0001). Despite frequent interruptions by SWJs, fixations were otherwise stable and indistinguishable from controls (root mean square [RMS] velocity, p = 0.324). The abnormal eye movement parameters were independent of disease duration, tremor severity, and medication therapy.

DISCUSSION

In contrast to normally swift onset and efficient acceleration/deceleration movements, saccades in ET are characterized by abnormally prolonged latencies and slowed velocity profiles. Although ET subjects maintain highly stable fixations, they are interrupted by increased numbers of SWJs. This study reveals novel oculomotor deficits in ET, which are distinct from the eye movement dysfunction of other movement disorders, supporting a role for eye tracking to assist in the differential diagnoses of not only atypical, but also more common movement disorders.

Developmental dyslexia and vision

Developmental dyslexia affects almost 10% of school-aged children and represents a significant public health problem. Its etiology is unknown. The consistent presence of phonological difficulties combined with an inability to manipulate language sounds and the grapheme-phoneme conversion is widely acknowledged. Numerous scientific studies have also documented the presence of eye movement anomalies and deficits of perception of low contrast, low spatial frequency, and high frequency temporal visual information in dyslexics. Anomalies of visual attention with short visual attention spans have also been demonstrated in a large number of cases. Spatial orientation is also affected in dyslexics who manifest a preference for spatial attention to the right. This asymmetry may be so pronounced that it leads to a veritable neglect of space on the left side. The evaluation of treatments proposed to dyslexics whether speech or oriented towards the visual anomalies remains fragmentary. The advent of new explanatory theories, notably cerebellar, magnocellular, or proprioceptive, is an incentive for ophthalmologists to enter the world of multimodal cognition given the importance of the eye's visual input.

Prevalence of ocular motor cranial nerve palsy and associations following stroke

AIM

Occurrence of ocular motor cranial nerve palsies (OMCNP), following stroke, has not been reported in relation to the type of OMCNP seen and in relation to brain area affected by stroke. The aim of this study was to identify all patients referred with suspected visual impairment to establish the presence and type of OMCNP.

METHODS

Prospective, observation study with standardised referral and assessment forms across 20 sites. Visual assessment included visual acuity measurement, visual field assessment, ocular alignment, and movement and visual inattention assessment. Multicentre ethics approval and informed patient consent was obtained.

RESULTS

In total, 915 patients were recruited with mean age of 69.18 years (SD 14.19). Altogether, 498 patients (54%) were diagnosed with ocular motility abnormalities. Of these, 89 patients (18%) had OMCNP. Unilateral third nerve palsy was present in 23 patients (26%), fourth nerve palsy in 14 patients (16%), and sixth nerve palsy in 52 patients (58%). Out of these, 44 patients had isolated OMCNP and 45 had OMCNP combined with other ocular motility abnormalities. Location of stroke was reported mainly in cerebellum, brain stem, thalamus, and internal and external capsules. Treatment was provided for each case including prisms, occlusion, typoscope, scanning exercises, and refraction.

CONCLUSIONS

OMCNP account for 18% of eye movement abnormalities in this stroke sub-population. Sixth CNP was most common, followed by third and fourth CNP. Half were isolated and half combined with other eye movement abnormality. Most were treated with prisms or occlusion. The reported brain area affected by stroke was typically the cerebellum, brain stem, and diencephalic structures.