Different Positions Of Gaze Research Articles

Improvement of surgical treatment of Duane syndrome in children

To analyze the use of bifurcation of the lateral rectus muscle (LRM) in the surgical treatment of Duane syndrome (DS) in children. The analysis of surgical treatment involved 12 children with paralytic strabismus at the age of 8 to 17. The following research methods were conducted for all patients: the study of eye motility in different directions of gaze, the study of eyes position and the degree of deviation in different positions of gaze, the Bielschowsky test, the Park's three-step test, determination of the nature of torticollis, the forcing test - intraoperative forceps test, multislice computed tomography (MSCT) of the head and orbit, ultrasonography of the oculomotor muscles. All study children underwent bifurcation (Y-cleavage procedure) of LRM with recession in exo-DS in 17% of cases, without recession in eso-DS - 83% of cases, respectively. In all operated patients with Duane syndrome, the direction of LRM was compensated (downshoot and upshoot were eliminated). In a direct gaze, the correct position was achieved in 10 (83%) cases, in 2 (17%) the residual angle of up to 10 PD remained, and torticollis was eliminated in 9 (75%) patients. The method of LRM bifurcation - the procedure of dividing the muscle into two portions and changing its primary localization, accompanied by abnormalities (presence of deviation, retraction, anomalous vertical movements, limited ocular motility, etc.), - helps compensate for them, and provides cosmetic as well as functional improvement.

Double vision in adults

ABSTRACTPurpose: To determine the patient characteristics, patterns in presentation and incidences of the various etiologies in adult patients with the chief complaint of double vision.Design: Retrospective review.Subjects: All persons greater than 18 years of age who presented to a single provider (DG) in a nonacademic private practice over a 2-year period, from 2011 to 2013, with the chief complaint of double vision. The provider is part of a multispecialty eye care group practice with both ophthalmologists and optometrists. This group practice provides a large adult referral base.Methods: Examination for each patient included refraction, versions, alignment in different positions of gaze at distance and at near, binocular sensory testing, neuro-ophthalmologic examination, and dilated fundus examination if not recently documented. Alignment was measured with cover–uncover testing and alternate cover testing with prism bars or free prisms, using Snellen letters for fixation. Appropriate refractive correction was ensured. Alignment was measured in the primary position at distance and in gaze directed 20 degrees L, R, up, and down. The near deviation was measured in the reading position with the large letters on a near card for fixation. Sensory testing was performed with the Worth 4-dot at distance and near and with the Titmus stereopsis test. Vectograph testing was also performed at distance on many patients, particularly those with small-angle deviations. The prismatic correction necessary to correct diplopia subjectively at distance in the primary position and at near in the reading position was also recorded.Primary outcome: Ocular alignment and etiology of diplopia. Management, response to treatment, and outcome were also recorded.Results: A total of 125 patients were included in the analysis. Subjects ranged from 18 to 93 years of age. Most cases of idiopathic strabismus were in the elderly, but the age range varied with category of underlying strabismus. Small-angle HT was the most common type of strabismus, comprising 21% of all subjects. ET, usually of the divergence insufficiency type (20%); XT (14%); and palsies not including trochlear palsy (12%) and trochlear palsy (8%) were the next most common etiologies. No strabismus was found in 11% of subjects.Conclusions: Most cases of diplopia in adults presenting as an outpatient can be classified into a few categories based on their type of strabismus. These categories of strabismus share typical age ranges and features. While diplopia in adults is usually idiopathic, diplopia can be the presenting sign of serious underlying pathology. Thus, a thorough history; examination; and, in some cases, diagnostic testing is necessary.

Acute vestibular syndrome : Clinical examination outperforms MRI in the detection of central lesions

Asignificant number of patients who seek medical treatment in an emergency department because of vertigo or dizziness, suffer from acute vestibular syndrome. This is characterized by sustained vertigo, horizontal or horizontal rotatory jerk nystagmus, and unsteady stance and gait. In the acute situation it is crucial to differentiate patients with aperipheral vestibular disorder from those with acentral disease. Anumber of recent studies have shown that astructured clinical examination enables areliable differential diagnosis of central or peripheral disorders. Such an examination includes the head impulse test, an alternating cover test to detect askew deviation of the eyes, and observation of nystagmus in different positions of gaze and using Frenzel goggles. This examination is more sensitive for the detection of brainstem stroke than magnetic resonance imaging (MRI), at least within 48 h after symptom onset. As these facts are still little known, in practice there is an overuse of cost-intensive imaging with computed tomography and MRI, and anumber of patient brainstem strokes in the vertebrobasilar circulation may be missed. This paper describes the relevant studies on this topic.

Temporary management of diplopia with botulinum toxin in multiple ocular motor cranial neuropathies

To report management of diplopia with botulinum toxin injection in traumatic multiple ocular motor cranial neuropathies. Alternate prism and cover measurement of deviation in different positions of gaze, examination of ductions, field of binocular single vision, and complete ocular anterior and posterior segment evaluation were carried out. CT and MRI of the orbit were available. We describe a case of traumatic VI, IV, and mainly superior III cranial nerve palsies, with left hypotropia of 35 prism diopters and esotropia of 45 prism diopters and incapacitating diplopia, due to fracture of the roof and lateral wall of the orbit, extending to the superior orbital fissure, as demonstrated by CT and MRI of the orbit. Severe limitation of abduction, elevation, and depression of the left eye was found. A single botulinum toxin injection in the medial rectus with diffusion to the inferior rectus was effective as a temporary measure for the treatment of diplopia and attainment of a small field of binocular single vision. The patient remained symptom-free for 5 months after injection. Botulinum toxin injection may be useful for the temporary management of diplopia in multiple ocular motor cranial neuropathies.

Visual rehabilitation following cerebellar stroke

Aim: To present a small case series of patients with visual complications following primary acute cerebellar stroke, document the types of visual deficit that occur, examine recovery patterns and identify rehabilitation strategies available. Methods: A small, consecutive case series of patients referred to the Orthoptic Stroke Service at Sheffield Teaching Hospitals NHS Foundation Trust with primary acute cerebellar stroke in 2007–2008 is presented. The types of visual deficit that occurred and the orthoptist’s contribution to patient rehabilitation are outlined. Results: Seven patients were included in this series. All had manifest nystagmus with or without oscillopsia. The main complaint was of ‘blurred vision’. Nystagmus varied in different positions of gaze, down gaze being the most troublesome for rehabilitation. Other deficits identified were skew deviation, internuclear ophthalmoplegia, and fixation abnormalities including saccadic intrusions and square wave jerks. Recovery was often incomplete, although in most cases some functional improvement did occur and most often in primary position. Conclusions: Patients who have suffered cerebellar stroke, especially those with vague visual symptoms and those failing to respond to rehabilitation, should be referred for orthoptic assessment. This provides invaluable information that can explain difficulties with rehabilitation and give patients insight into their symptoms. Advice and therapy can help overcome problems in many cases.

Prevalence of diabetic retinopathy in patients with recently diagnosed diabetes mellitus

Background: The severity of diabetic retinopathy is well known to have a close association with the duration of diabetes mellitus. Patients with recently diagnosed diabetes should have adequate eye examinations to eliminate the possibility of diabetic retinopathy being present because there is no accurate means of determining the duration of the disease. The prevalence of diabetic retinopathy in type 2 diabetic patients with known duration up to one year was investigated in the present study.Methods: A centre for diabetic retinopathy screening was set up in a community in Hong Kong. The screening procedures included history taking, visual acuity measurement, anterior ocular health assessment and retinal examination by fundus photography. Fundus photographs were taken in nine different positions of gaze through natural or dilated pupils. Using the criteria recommended by the American Optometric Association the retinopathy was graded in severity. ‘Recently diagnosed diabetes mellitus’ was defined as having diabetes diagnosed by a physician within the previous year.Results: A total of 12,112 patients having their first visits to the centre were recruited from 2006 to 2009. Among them, 3,510 patients had recently diagnosed diabetes. The mean age of patients was 59.5-years. The prevalence of diabetic retinopathy was 18.2 per cent (639 patients) among the recently diagnosed diabetic patients. Most of the patients had mild non‐proliferative diabetic retinopathy. In these 639 patients, approximately seven per cent had sight‐threatening retinopathy that included significant macular oedema, all of whom required monitoring. The presence of hypertension or smoking was not significantly associated with the prevalence of diabetic retinopathy in recently diagnosed diabetic patients.Conclusions: Screening for diabetic retinopathy is important for newly diagnosed diabetic patients. In Hong Kong, the prevalence of diabetic retinopathy was alarmingly high and some patients had already developed sight‐threatening retinopathy that included macular oedema. Most of them had no symptoms until the retinopathy progressed and they developed macular oedema. A systematic screening program in the community is needed for early detection and to reduce blindness in diabetic patients.

Dose–response relationship in inferior oblique muscle recession

Recession of the inferior oblique muscle is a widely applied operation in the treatment of strabismus sursoadductorius. In this retrospective study, the dose-response relationship of this procedure was determined in order to improve surgical outcomes. In particular, the effect of an additional anteroposition of the operated muscle was analysed, as well as differences between short and long term results. This retrospective study included 37 patients. Inclusion criteria were unilateral strabismus sursoadductorius and normal retinal correspondence. Exclusion criteria comprised previous ocular muscle surgery and any ocular or orbital disease. Nineteen patients had received an additional anteroposition of the muscle. Patients were examined at a tangent screen pre-operatively and 1 day post-operatively (short-term effect). Sixteen patients underwent an additional examination 3 months post-operatively (long-term effect). Changes of vertical, torsional and horizontal deviations, measured in different positions of gaze, were related to the surgical dose in order to calculate the dose-response relationship by linear regression analysis. Surgery always reduced preoperative deviations. The short-term vertical dose-response without/with anteroposition was 0.6 degrees /0.5 degrees per mm in primary gaze and 1.2 degrees /1.1 degrees per mm in adduction. The short-term torsional dose-response without/with anteroposition was 0.8 degrees /0.5 degrees per mm in primary gaze. Three months later, the vertical effect had remained constant, whereas the torsional effect had decreased to 0.6 degrees /0.1 degrees per mm. Variance was high, e.g. the standard deviation of the short-term effect for the vertical deviation in adduction was 2.5 degrees . Despite the large variation of effects, a dose-response relationship could be established, facilitating surgical planning. Large vertical deviations with small excyclodeviation are an indication for additional anteropositioning. The torsional effect of inferior oblique muscle recessions can diminish over time.

Magnitude of Dissociated Vertical Deviation in the Different Positions of Gaze

Introduction and ObjectiveControversy exists about the amount of Dissociated Vertical Deviation (DVD) in the different positions of gaze. The objective was to evaluate the influence of oblique muscles overaction in the magnitude of Dissociated Vertical Deviation.Patients and MethodA prospective study both observational and comparative was performed in 64 patients which were divided into four groups: 1) without overaction of vertical muscles, 2) inferior oblique muscle overaction, 3) superior oblique muscle overaction and 4) overaction of all four oblique muscles. The magnitude of dissociated vertical deviation was measured and the amount was compared in adduction, primary position and in abduction.ResultsThe DVD was larger in adduction when it was associated with inferior oblique muscle overaction (P = 0.01) and bigger in abduction when it was related to superior oblique muscle overaction (P = 0.03). In the remaining groups, a non-characteristic pattern was observed.ConclusionThere is a difference in the magnitude of DVD in the different positions of gaze only when it is associated with oblique muscle overaction.

The Effect of Hyaluronidase on Akinesia During Cataract Surgery

The ability of hyaluronidase to improve akinesis in retrobulbar anesthesia was evaluated in a double-masked study. Forty consecutive patients undergoing cataract surgery were anesthetized with 3 ml of a 1:1 mixture of 4.0% lidocaine and 0.75% bupivacaine solution. In a predetermined randomized fashion, 2 ml of hyaluronidase (300 USP units) were added to half of the syringes, and 2 ml of saline to the remaining half. The level of akinesia was graded in six different positions of gaze. Seventy percent of the hyaluronidase group exhibited complete akinesis, while only 40% of the control group did. The mean scores for four out of six positions of gaze were significantly higher in the hyaluronidase patients than in the control group. Similarly, the hyaluronidase subjects showed a significantly higher sum score for the six sectors than did the control subjects (p = .0001). These results show that hyaluronidase significantly enhances akinesia. It is therefore recommended that it be included in the anesthetic regimen for such surgeries.

Graphic Analysis of Paralytic Strabismus with the Lancaster Red-Green Test

We used the Lancaster red-green test to monitor changes in ocular alignment in patients with paralytic strabismus. By inferring the position of the right eye and that of the left eye at many different positions of gaze and then plotting the data on a graph, one can derive a static eye position curve. The location of the curve relative to the line depicting normal ocular alignment ( orthophoria ) indicates whether there is an esodeviation or an exodeviation . The slope of a line drawn tangent to the curve indicates, for that particular point, whether the deviation is concomitant or not and which eye is relatively weak or restricted and by how much. This graphic technique provides a simple, sensitive, and quantitative measure of ocular alignment that may be especially useful for detecting subtle changes in the relative positions of the two eyes. This method may be a useful adjunct in the planning and evaluation of therapy for patients with paralytic strabismus.

The CT-topography of retrobulbar anesthesia. Anatomic-clinical correlation of complications and suggestion of a modified technique.

The anatomic relationship of an injection needle as traditionally placed in retrobulbar anesthesia to optic nerve, orbital vessels and eye muscles is demonstrated by computed tomography. The clinical complications of retrobulbar injections are reviewed and correlated to the orbital topography in different positions of gaze, as analyzed in anatomic sections and CT images. The results indicate that with the transitional technique of retrobulbar injection the most important orbital structures are in the immediate neighbourhood of the needle. A different injection technique is discussed.

Diagnosis and Treatment of Thyroid Myopathy

Twenty-five patients with thyroid myopathy were referred to our Strabismus Clinic for treatment of diplopia. Prism treatment was effective in only three. When the remaining 22 patients' ocular motility problems and thyroid states were stable, surgical management was undertaken. The preoperative evaluation included visual fields, iris angiograms, binocular diplopia fields, intraocular pressures in different positions of gaze and A-scan echography. The goal of surgery was to produce as large a binocular visual field from primary as possible. Supramaximal recessions of the involved muscles were often needed and adjustable sutures were an important part of the surgical management. The complications encountered included limitation of movement into the field of the recessed muscle, inducement of an A-pattern in downgaze, and postoperative instability.

Listing's law, eye position sense, and perception of the vertical

The vertical meridian of the eye does not remain vertical as the eye moves into oblique positions of gaze, but is tilted according to Listing's Law. In order to measure the relation between eye torsion and the apparent vertical, observers sat in darkness and set a luminous line to vertical for different positions of gaze. The responses of the subjects were not veridical, but deviated by an amount which was proportional to the torsion of the eye. Two conclusions were drawn: (1) there exists an extraretinal eye position signal which varies linearly with the torsion of the eye (2) the gain of the signal is much less than 1.0 and is thus insufficient to insure a correct perception of the vertical.

Anomalous Retinal Correspondence in Different Positions of Gaze

Anomalous Retinal Correspondence in Different Positions of Gaze

Eye movement recordings in neurological disorders.

Anomalies of eye movements occur in many disorders involving the central nervous system. Usually, description of such anomalies is based on gross clinical observations alone, using such tests as the following: Pursuit movements are tested by having the patient follow a flashlight that is moved slowly back and forth before his eyes. The ability to fixate and refixate laterally displaced targets (movement of regard, saccadic movement) is examined by asking the patient to look quickly between two objects held to the right and left before his eyes. The presence or absence of spontaneous nystagmus in different positions of gaze is noted, but amplitude and frequency are difficult to analyze in this manner. Observation of the eyes during such tests is undoubtedly an adequate method to detect gross anomalies of eye movements. However, it is obvious that more refined methods to analyze eye movements are not only more likely to provide