Abnormal Eye Position Research Articles

Abnormal Eye Position.

Abnormal Eye Position.

Simultaneous cardio‐cerebral infarction in a dog

AbstractA 4‐year‐old, spayed, female, mix‐breed dog presented for acutely rolling to the left. She had developed an apathetic behaviour over the last 5 months and also recurrent urinary tract infections. On presentation, cardiac auscultation revealed a fast heart rate and premature beats. The dog was stuporous, with a head tilt to the left, abnormal eye position and movements and absent facial sensation on the left side of the head. Clinicopathologic analysis was consistent with hypothyroidism. Electrocardiography evaluation revealed an accelerated idioventricular rhythm interrupted by ventricular premature complexes. Postmortem examination revealed infarction of the right thalamus due to an occlusive thrombus associated with atherosclerosis, together with acute myocardial infarction of the left ventricular wall with an associated thrombus and atherosclerosis in a supplying coronary artery. This report illustrates a concurrent cardio‐cerebral infraction in a dog. Neurological and electrocardiographic abnormalities are explained, and the pathophysiology of the clinical signs is discussed.

Abnormal Eye Position Signals in Interstitial Nucleus of Cajal in Monkeys With "A" Pattern Strabismus.

PurposePattern strabismus is characterized by a cross-axis pattern of horizontal and vertical misalignments. In A-pattern strabismus, for example, a divergent change in the horizontal misalignment occurs on downgaze. Work with nonhuman primate models has provided evidence that this disorder is associated with abnormal cross-talk between brainstem pathways that normally encode horizontal and vertical eye position and velocity. Neurons in the interstitial nucleus of Cajal (INC) are normally sensitive to vertical eye position; in the present study, we test the hypothesis that, in monkeys with pattern strabismus, some INC neurons will show an abnormal sensitivity to horizontal eye position.MethodsMonkeys were rewarded for fixating a visual target that stepped to various locations on a tangent screen. Single neurons were recorded from INC in one normal monkey, and two with A-pattern strabismus. Multiple linear regression analysis was used to estimate the preferred direction for each neuron.ResultsIn the normal monkey, all INC neurons had preferred directions within 20° of pure vertical (either up or down). The preferred directions were significantly more variable in the monkeys with pattern strabismus, with a minority being more sensitive to horizontal eye position than vertical eye position. In addition, the vertical eye position sensitivity was significantly less in the monkeys with strabismus.ConclusionsIn pattern strabismus, neurons in INC show neurophysiological abnormalities consistent with a failure to develop normal tuning properties. Results were consistent with the hypothesis that, in pattern strabismus, INC receives an abnormally strong signal related to horizontal eye position.

Vertical disconjugacy during reading in dyslexic and non-dyslexic children

PurposeThe objective of this study was to explore vertical binocular coordination in dyslexic and non-dyslexic children during saccades and post-saccadic fixation period while reading a text. MethodsBinocular eye movements were recorded by an infrared system (Mobile T2®, SuriCog) in thirty-six dyslexic children from 7.3 to 13.6 years of age (mean age: 10.4 ± 0.3 years) who were asked to silently read a four-line text during binocular viewing. Data were compared to those of thirty-six age-matched non-dyslexic children. ResultsVertical disconjugacy during post-saccadic fixation was higher in dyslexic children with respect to non-dyslexic children group. Vertical disconjugacy was not age-dependent either for dyslexic children or for non-dyslexic children. ConclusionsThe poor binocular vertical coordination observed in dyslexic children while reading could suggest a deficiency in the cerebellum and/or extra-ocular muscles involved in vertical eye alignment. Moreover, the fact that this vertical binocular coordination was not age-dependent could be due to an abnormal eye position and/or to a dysfunction of midbrain structures involved in vertical vergences.

Altered functional connectivity of primary visual cortex in adult comitant strabismus using resting‐functional mri

AbstractPurpose Strabismus is not only associated with an abnormal eye position, but also with abnormal eye movement and poor stereopsis, both of which may be associated with high brain function. The aim of this study was to examine the functional connectivity between primary visual cortex and other cortical areas during rest in normal subjects and patients with comitant strabismus using functional magnetic resonance imaging.Methods Functional magnetic resonance imaging (fMRI) was carried out on ten patients with comitant exotropia and eleven well‐matched healthy subjects while all were in a resting state. The primary visual cortex was selected as the region of interest and the resting‐state functional connectivities of this area were analyzed.Results Compared with normal controls, strabismic patients showed that left BA17 had decreased functional connectivity with the right parietal lobe, left middle frontal gyrus, left superior frontal gyrus and right cerebellum, while the functional connectivity of the right BA17 was decreased at the middle frontal gyri bilaterally and the left inferior frontal gyrus. Enhanced connectivity of right BA17 to the bilateral middle occipital gyrus was also identified.Conclusion These data suggest that functional dysconnectivity between primary visual cortex and other cortical areas may exist in patients with comitant strabismus, and the abnormal connectivity may be associated with abnormal eye movement and loss of stereopsis.

Metastatic orbital tumors in southern China during an 18-year period

To determine the primary sites, clinical features, treatment, and outcome of 46 patients with cancer metastatic to the orbits in southern China. Retrospective review of medical records at a tertiary center in southern China between Jan 1, 1991 and Dec 31, 2008. The study included 35 males and 11 females, with an age range of 3-78years (average 47years). All of the patients came from southern China. The left orbit was affected more frequently than the right orbit (3:2), and no cases were bilaterally involved. The most common primary cancer that metastasizes to the orbit is nasopharyngeal carcinoma (30.34%), followed by lung cancer (8.70%), liver cancer (6.52%), breast carcinoma (4.35%), renal cell cancer (4.35%), medullary thyroid carcinoma (2.17%), lacrimal gland carcinoma (2.17%), stomach carcinoma (2.17%), mediastinum carcinoma (2.17%), other forms (6.52%), and unknown carcinomas (30.34%). Orbital metastasis was the first sign of systemic cancer in 24 patients (52.17%). The five most common clinical findings at the initial examination were abnormal eye position (65.22%), proptosis (63.04%), increased orbital pressure (54.35%), diplopia (54.35%), and limited ocular motility (52.17%), followed by swollen eyelid (50%), visible mass or swelling (46%), blurred vision (41%), conjunctival hyperemia, and edema (35%), pain (28%), blepharoptosis (20%), papilledema (17%), and vasodilatation of the retina (7%). Primary treatment included surgical excision, radiotherapy, systemic chemotherapy, and observation. Among the patients (78% of 46) with sufficient follow-up time (mean 20.7months), 30.56% of them died of disseminated metastasis. Twenty-five percent of them were in remission with no active metastases and 27.78% of them were living with active metastases. Overall, the mean survival time was 18months (range, 5-38months) after diagnosis of orbital metastasis. The most common primary cancer that metastasizes to the orbit is nasopharyngeal carcinoma (30.34%), followed by lung cancer (8.70%) and liver cancer (6.52%) in southern China. Orbital metastasis can display a variety of clinical features and should be considered in patients with known systemic cancer. The systemic prognosis is generally poor.

Psychosocial implications of strabismus surgery in adults.

Adults with socially noticeable strabismus have been known to experience psychosocial difficulties as a result of their abnormal eye position. This study was designed to assess the impact of noticeable strabismus in adults and the psychosocial effects of surgical correction. A total of 31 adults who underwent surgery for longstanding horizontal strabismus where poor alignment was the primary reason for consenting to surgery were requested to complete a self-reporting repertory grid to appraise the psychosocial consequences of corrective strabismus surgery. Prior to corrective surgery, the majority of subjects reported various psychosocial difficulties, considered by them to be wholly or partly due to their unsightly strabismus. A significant improvement in interpersonal interactions is apparent following strabismus surgery. Surgery to improve ocular alignment appears to herald major improvements in the quality of psychosocial functioning for the majority of adults undergoing such surgical procedures (P < 0.001).

Eye movement abnormalities in systemic lupus erythematosus

Objective: To describe eye movement abnormalities in patients with systemic lupus erythematosus (SLE). Design: Between January 1,1970, and June 30,1995,113 patients with a clinical diagnosis of SLE were examined. Of these, 33 had ocular motor abnormalities and a diagnosis of SLE as defined by the revised criteria of the American College of Rheumatology. Setting: Patients hospitalized on the wards of the Los Angeles County—University of Southern California Medical Center, Los Angeles. Subjects: Thirty-three patients, 82% women, ranging in age from 19 to 58 years (mean, 33.5 years). The average duration of SLE was 3.5 years, and 10 patients had been symptomatic for 5 years or longer. Results: Of 55 ocular motor signs, 33 involved limitation of eye movements or abnormal eye position at rest; abnormal spontaneous eye movements occurred 12 times; ptosis was seen in eight patients and psychogenic signs in two. Sixteen patients (48%) had brainstem infarcts; 11 had other known causes, including three with meningitis, two with hysteria, and one each with ocular myositis, pseudotumor cerebri, both ocular myositis and pseudotumor cerebri, Guillain-Barre syndrome, hyperosmolality, and hypoxic encephalopathy. In four patients with isolated sixth nerve palsies and two with isolated ptosis, the cause remained unknown. Conclusions: Ocular motor signs in SLE are uncommon and often transitory. When present, they help to ascertain the location, and often the cause, of neurologic involvement.

Eye movement abnormalities in systemic lupus erythematosus.

To describe eye movement abnormalities in patients with systemic lupus erythematosus (SLE). Between January 1, 1970, and June 30, 1995, 113 patients with a clinical diagnosis of SLE were examined. Of these, 33 had ocular motor abnormalities and a diagnosis of SLE as defined by the revised criteria of the American College of Rheumatology. Patients hospitalized on the wards of the Los Angeles County-University of Southern California Medical Center, Los Angeles. Thirty-three patients, 82% women, ranging in age from 19 to 58 years (mean, 33.5 years). The average duration of SLE was 3.5 years, and 10 patients had been symptomatic for 5 years or longer. Of 55 ocular motor signs, 33 involved limitation of eye movements or abnormal eye position at rest; abnormal spontaneous eye movements occurred 12 times; ptosis was seen in eight patients and psychogenic signs in two. Sixteen patients (48%) had brain-stem infarcts; 11 had other known causes, including three with meningitis, two with hysteria, and one each with ocular myositis, pseudotumor cerebri, both ocular myositis and pseudotumor cerebri, Guillain-Barré syndrome, hyperosmolality, and hypoxic encephalopathy. In four patients with isolated sixth nerve palsies and two with isolated ptosis, the cause remained unknown. Ocular motor signs in SLE are uncommon and often transitory. When present, they help to ascertain the location, and often the cause, of neurologic involvement.

Acceleration by NMDA treatment of visually induced map reorganization in juvenile Xenopus after larval eye rotation

Each tectal lobe of Xenopus frogs receives two topographic maps, one via the ipsilateral eye and one via the contralateral eye. The alignment of the ipsilateral map with the contralateral map depends upon binocular visual input during a critical period that extends from late tadpole to early juvenile stages. Rotation of one eye during the critical period leads to reorganization of the ipsilateral map, which eventually comes back into alignment with the contralateral map despite the abnormal eye position. The ipsilateral eye's map initially develops as if there had been no alteration in eye position; there is a delay of 4-6 weeks before reorganization can be detected by electrophysiological mapping. In this paper, the possible role of the NMDA receptor in the delay in reorganization is addressed. The degree of NMDA receptor activation may need to be above some threshold level to trigger reorganization. If NMDA receptor activation normally is below that level until after the first month postmetamorphosis, then exogenous NMDA might boost the process sufficiently to start the reorganization process sooner than usual. In order to test this possibility, the left eye of tadpoles was rotated and NMDA was applied to the right tectal lobe for 3-5 weeks, starting at 1 week postmetamorphosis. Electrophysiological mapping demonstrated that reorganization takes place more rapidly than in untreated frogs or frogs treated with vehicle only. This result is consistent with the interpretation that the activation of the NMDA receptor is a rate-limiting step in the activity-dependent matching of binocular maps in Xenopus tectum.

Postoperative Course of Traumatic Cataract

The visual recovery in traumatic cataract have much improved, because of introduction of microsurgery and of progress in postoperetive manegement or pleoptics. Only a few reports are available on the prognosis for the binocular function. Eight patients after unilateral traumatic cataract operation, who complained diplopia just after the contact lens wearing, were reviewed in postoperative course of visual acuity, binocular vision, eye position, and the relation to the duration of visual recovery.The length of the duration of visual recovery was well correlated with the degree of abnormal eye position, not with deterioration of binocular vision. Binocular vision was deteriorated in fusion and stereopsis, while simultaneous perception was maintained. This suggests the normal retinal correspondence. After the surgical correction of abnormal eye position, the range of fusion was improved.At the point of prognosis of visual function, there was a separation between visual acuity and binocular vision.We considered after unilateral traumatic cataract operation not only visual acuity but also binocular function should be followed-up.