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At least 127 records · Page 7Linked to original sources

PubMed2000

Comitant strabismus.

A review of the literature on comitant strabismus of the period from April 1999 until April 2000 is presented. A rather new and increasingly important issue is the psychosocial aspect of strabismus. Two studies have demonstrated that strabismus creates a significant negative social prejudice on the patients and that it can significantly reduce an applicant's ability to obtain employment. Subsequently, strabismus surgery can no longer be called "cosmetic". Concerning the timing of surgery in congenital esotropia, it was reported that early surgery does not ensure continued alignment, but frequently requires additional operations. The increased risk of early-onset strabismus in prematurely born children was confirmed by several studies, and the importance of regular ophthalmologic controls of all preterm infants screened for retinopathy of prematurity was stressed. It was reported that risk factors are cicatricial retinopathy of prematurity, refractive error, family history of strabismus, and poor neurodevelopmental outcome, rather than low gestational age and regressed acute retinopathy of prematurity. A number of other aspects of interest concerning exotropia, esotropia, and dissociated vertical deviation are presented in this review.

Anti-Dyskinesia Agents↗

PubMed2002

Flap tear of rectus muscles: an underlying cause of strabismus after orbital trauma.

PURPOSE: To present an avulsion injury of the rectus muscle after orbital trauma, usually the inferior rectus, and detail its diagnosis and operative repair. METHODS: Forty-three patients underwent repair of flap tears of 62 rectus muscles. During surgery, we found the muscle abnormality was often subtle, with narrowing or thinning of the remaining attached global layer of muscle. The detached flap of external (orbital) muscle was found embedded in surrounding orbital fat and connective tissue. Retrieval and repair were performed in each case. RESULTS: The causes of orbital trauma were as follows: orbital fractures (15 patients), blunt trauma with no fracture (11 patients), suspected trauma but did not undergo computerized tomographic scan (12 patients), and status after retinal detachment repair (5 patients). Of note, 15 of the 43 patients (35%) underwent repair of the flap tear alone, without any additional orbital or strabismus surgery. Diagnostically, the predominant motility defect in 45 muscles was limitation toward the field of action of the muscle, presumably as a result of a tether created by the torn flap; these tethers simulated muscle palsy. Seventeen muscles were restricted away from their field of action, simulating entrapment. The direction taken by the flap during healing determined the resultant strabismus pattern. All patients with gaze limitation toward an orbital fracture had flap tears. The worst results after flap tear repair were seen in patients (1) who had undergone orbital fracture repair before presentation, (2) who had undergone previous attempts at strabismus repair, and (3) who had the longest intervals between the precipitating event and the repair. The best results were obtained in patients who underwent simultaneous fracture and strabismus repair or early strabismus repair alone. CONCLUSIONS: Avulsion-type flap tears of the extraocular muscles are a common cause of posttraumatic strabismus. Early repair produces the best results, but improvement is possible despite long delay.

Adolescent↗

PubMed1991

Length-tension recording system for strabismus surgery.

To meet the need for both scientific information and a clinical means for measurement of the mechanical parameters of the most difficult individual strabismus cases we present a technique for directly measuring and plotting the length-tension characteristics of the tissues supporting the eye. Semiconductor strain gauges mounted on the shanks of a custom machined eye forceps and an ultrasonic method of making continuous duction measurements of the eye have proved feasible. When the forceps are interfaced with a dedicated microcomputer, the system provides a permanent, quantitative, length-tension record displayed in real-time. The instrumented length-tension forceps system has provided a noninvasive means for quickly and simply assessing the mechanical underlying determinants of strabismus pathology in the office, the laboratory or in the operating room, and can aid in the planning and immediate intraoperative alteration of strabismus surgery. Under operator coordination, measurements can be made which precisely define the mechanical load which the eye muscles must move. The resulting objectively determined tissue stiffness asymmetries and muscle restrictions limiting ocular motion indicate the purely mechanical contributions to a patient's strabismus. Measurements of active force indicate the magnitudes and patterns of innervation over the entire range of gaze. By comparison of these active force and passive stiffness records, nerve signal imbalances may be quantitatively distinguished from mechanical imbalances in strabismus. It is the detailed interaction of these nonlinear muscle forces and mechanical elements which determines the position of each eye in strabismus and therefore the proper surgical treatment. A brief description of actual use and a few examples of clinical results are included from over 200 human records.

Calibration↗

PubMed1999

Risk factors for strabismus in children born before 32 weeks' gestation.

AIM: To investigate risk factors associated with strabismus in children born prematurely. METHODS: Prospective study of all children born before 32 weeks' gestation between 1 January 1990 and 31 December 1991 in a geographically defined population of approximately 3 million in the Northern Region of the United Kingdom. All children were examined aged 2 years by the same ophthalmologist and paediatrician. RESULTS: 558 children (98.6% of study group) were examined. Logistic regression showed an increased risk of strabismus in children with cicatricial retinopathy of prematurity (p=0.02), refractive error (p=0.003), family history of strabismus (p<0.0001), and poor neurodevelopmental outcome (p<0.0001), in particular impaired locomotor skills (p=0.008) and hand-eye coordination (p=0. 001). Gestational age and regressed acute ROP were not independent risk factors for strabismus (p=0.92 and 0.85 respectively). CONCLUSIONS: This study has identified factors which are independently related to strabismus (although not necessarily causative) and others which are related only indirectly. This may contribute both to the management of children born prematurely and to future studies of the aetiology of strabismus.

Child Development↗

PubMed2006

Body sway increases immediately after strabismus surgery.

The purposes of this study were to examine whether body sway is altered immediately after strabismus surgery in children and to find preoperative clinical factors associated with body sway. In a prospective study, body sway was measured on 1-3 days before surgery and on the third day after surgery; for the measurements, computerized static stabilometry was carried out on 28 consecutive patients with strabismus (age range: 3 to 12 years old; mean: 7.4) who underwent strabismus surgery under general anesthesia. The linear length of the sway path (cm), the linear length of the sway path in a particular unit of time (cm/second), and the area of the sway path (cm2), indicative of the extent of body sway, all increased significantly among a total of 28 patients in both conditions of the patient's eyes open and closed, as well as among those in a subgroup of 16 patients with exotropia, after they had undergone strabismus surgery (p < 0.05, Wilcoxon signed ranks test). The center of pressure along the Y axis of orientation from the toe to the heel was found to deviate significantly toward the heel postoperatively, as compared with the preoperative center in the subgroup of 16 patients with exotropia (p < 0.05). Before surgery, 15 patients with no stereoacuity exhibited a greater amount of body sway when their eyes were open than did 13 patients with measurable stereoacuity (p < 0.05, Mann-Whitney U-test). In the subgroup of 16 patients with exotropia when their eyes open, 3 patients with abnormal head posture exhibited more extensive body sway than did 13 patients without abnormal head posture (p < 0.05). Body sway was found to significantly increase immediately after strabismus surgery in children with strabismus. Stereoacuity and abnormal head posture are 2 clinical factors associated with preoperative postural instability.

Child↗

PubMedDate not supplied

Psychosocial implications of strabismus surgery in adults.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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).

Adolescent↗

PubMedDate not supplied

Changes in corneal and conjunctival sensitivity, tear film stability, and tear secretion after strabismus surgery.

PURPOSE: Some patients complain of a foreign body sensation, a burning sensation, or dryness after strabismus surgery. We prospectively investigated the changes in corneal and conjunctival sensitivity, tear film stability, and tear secretion after strabismus surgery. PATIENTS AND METHODS: Corneal and conjunctival sensitivity were assessed with an esthesiometer, tear film breakup time was measured, and the Schirmer test was performed prospectively (preoperatively and 1 week, 1 month, and 3 months postoperatively) in 83 patients (124 eyes) who underwent strabismus surgery at our institution. RESULTS: There were no significant changes in corneal sensitivity, tear film stability, or tear secretion after strabismus surgery (P > .05). Conjunctival sensitivity decreased significantly after strabismus surgery (P < .05). CONCLUSION: Discomfort and dryness after strabismus surgery do not seem to be related to changes in corneal sensitivity, tear film stability, or tear secretion.

Adolescent↗

PubMed2004

[Treatment of strabismus associated with psychomotor impairment using botulinum toxin].

PURPOSE: Strabismus is associated with 80% of people with psychomotor retardation. Surgical treatment is difficult owing to brain instability. The aim of this study is to determine the efficacy of a direct application of botulinum toxin in cases strabismus related to psychomotor retardation. METHODS: This is a retrospective, longitudinal, observational study of treatment of strabismus associated to brain damage (under the Laws of Health of Mexico) using a direct application technique of botulinum toxin, considering age, type of strabismus, number of toxin applications, response and cause of brain damage. RESULTS: We analyzed 30 patients, age: 3.5 years old (S.D.: 2), follow-up 12.7 (S.D.: 2.3 months). Eighty percent of the patients had moderate psychomotor retardation and 20% had a severe retardation. The response was good in 44% and moderate in 24%, there were no cases without response. The patients were treated with 1.7 (S.D.:1) injections of toxin. Age and type of strabismus was not related to success of treatment (X2: 9.4; 7.8 to null hypothesis). First application of toxin determines the response to treatment (Fisher test: <0.05). Moderate retardation was related to better response. Bad results were related to unstable brain disease. CONCLUSIONS: The difficulty and prognosis of surgical treatment of strabismus in patients with brain damage and psychomotor retardation, causes us to consider the use of botulinum toxin as the first choice for this cases.

Botulinum Toxins, Type A↗

PubMed1999

[Acquired progressive esotropia and acquired strabismus fixus].

BACKGROUND AND PURPOSE: We previously reported on acquired convergent strabismus fixus and its incomplete type of esodeviation, which we named acquired progressive esotropia. In this study, we tried to confirm that the esotropia was acquired and progressive and to determine the most appropriate surgical procedure. SUBJECTS AND METHODS: Forty-three cases, 32 of acquired progressive esotropia and 11 of acquired convergent strabismus fixus with severe myopia, were rechecked to evaluate their clinical and physiological features. Thirty-seven cases underwent strabismus surgery and the surgical results were also evaluated. RESULTS: We obtained positive proof that the esodeviation was an acquired situation and progressed into convergent strabismus fixus from some pictures at a young age. The condition of some of these patients developed into convergent strabismus fixus in a short time. Combined recession-resection operation and transposition of superior and inferior rectus muscles were effective for the patients without severe abducting disorders. CONCLUSION: We must make a certain diagnosis of progressive esotropia in the early stages, because the condition of some of these patients will develop into strabismus in a short time if we miss the appropriate time for surgery.

Adult↗

PubMed2001

[Examination of eye position after strabismus surgery in Kawasaki Medical School Hospital].

PURPOSE: To examine the factors which affect changes in the position of the eyes following the strabismus surgery. METHODS: The postoperative position of 240 eyes with concomitant strabismus was examined. The factors which seemed to have an effect on the position of the eyes were enumerated, and a logistic regression analysis of the results was done. RESULTS: In comparison with esotropia, in exotropia the eyes showed a tendency to return gradually to a normal position. There was no remarkable improvement in stereoscopic vision following strabismus surgery. Based on the standards of the Japanese Association of Strabismus and Amblyopia [the cure standard for strabismus], the results of strabismus surgery were as follows: Grade 1(cosmetically satisfactory) was mainly observed for esotropia, and Grade 3(good) for exotropia. The factors which had a significant effect on the postoperative position of the eyes were as follows: esotropia amblyopia, muscle movement, and operative methods; exotropia: retinal correspondence, operative methods, and the necessity of inferior oblique muscle surgery. CONCLUSIONS: There was little correction of the position of the eyes. In individual cases, the factors which affect position of eyes were examined, and it was considered necessary to increase the amount of correction. Age is a factor which has an effect, but the effect on esotropia and exotropia is small.

Adolescent↗

PubMed2002

Binocular coordination of saccades in children with strabismus before and after surgery.

PURPOSE: To examine the quality of binocular coordination of saccades in children with various types of strabismus and the effect of strabismus surgery. METHODS: Eight subjects were tested (5-15 years old): five with convergent strabismus, three with divergent strabismus. A standard saccade paradigm was used to elicit horizontal saccades to target LEDs (5 degrees to 15 degrees ). Saccades from both eyes were recorded simultaneously with the photograph-electric Skalar IRIS device (Delft, The Netherlands). This task was run before and about 3 weeks after strabismus surgery. RESULTS: Before surgery, the difference in the amplitude of the saccade between the left eye and the right eye was larger (15% of the saccade size) than in normal children of similar age. After strabismus surgery for all subjects the squint angle was reduced, and the amplitude of the disconjugacy of saccades decreased significantly, dropping to normal values (6%). As in normal children, postsaccadic eye drift (both its conjugate and its disconjugate components) was small in amplitude. The difference compared with normal subjects was that disconjugate drift did not restore the disconjugacy of the saccade itself (e.g., in normal subjects drift is convergent when saccade disconjugacy is divergent and vice versa). Rather, disconjugate drift tended to drive the eyes toward static eye misalignment (e.g., the drift was mostly convergent for convergent strabismics and divergent for divergent strabismics). Surgery had no significant effect on either component of the drift. CONCLUSIONS: The improvement of the binocular coordination of the saccades could be due, at least partially, to central adaptive mechanisms rendered possible by surgical realignment of the eyes. Separate mechanisms control the binocular coordination of saccades and the alignment of the eyes during the postsaccadic fixation period.

Adolescent↗

PubMed1992

[Surgical treatment of strabismus in children (a 12-year study)].

A group of 2205 operations of strabismus in the course of 12 years reveals a clear predominance of operations of dynamic strabismus (94%), as compared with surgery of paralytic strabismus and ocular torticollis on account of nystagmus (6%). This fact provides evidence of a marked ratio of a non-paralytic aetiology of strabismus in the child population. In esotropia, the most frequent type of strabismus, the authors consider as most suitable the technique of weakening of the inner rectus muscles by a dosed elongation according to Gonin-Hollwich, as compared with the classical retroposition of this muscle. In exotropia the authors recommend reinforcing operations only or in combination with a weakening operation of the rectus muscles. The gradual development of application of the technique of surgery of the hyperfunctional lower oblique muscle is in favour of treble partial myotomy (elongation). They operate paretic strabismus when the IIIrd, IVth, VIth nerve are affected and supranuclear paresis of the levators by a complex procedure incl. transposition operations of the functional muscles. The authors operate ocular torticollis after a careful analysis of the congenital nystagmus, using special techniques on the rectus and oblique muscles which adjust the position of the head and bulbs.

Child↗

PubMed1992

Natural strabismus in monkeys. Convergence errors assessed by cover test and photographic methods.

A standard set of clinical prism and cover tests and a recently developed photographic method were used to assess binocular alignment in ten monkeys that previously were determined to have a naturally occurring infantile strabismus. Extensive measurements of the alignment state were made for fixation attempts throughout the field of gaze. Patterns of alignment errors were examined in an attempt to compared the strabismus found in individual monkeys with common syndromes of human infantile strabismus. Two monkeys showed patterns consistent with the syndrome of essential infantile esotropia. Five monkeys had patterns consistent with accommodative esotropia. One monkey that had bilateral anterior chamber hemorrhage at birth had a constant-angle esotropia. One monkey that previously had been shown to have a large-angle esotropia during development exhibited only exophoria, and in a final monkey in which large-angle esotropia was found during development, the strabismus had resolved. These results demonstrate that naturally occurring strabismus in monkeys might be related to syndromes seen in children. In addition, they provide extensive information about other characteristics of strabismus that have not been examined previously. These include a characterization of the magnitude of the misalignment in terms of error surface plots of bias and a detailed analysis of scatter in the measurements that show coupling relationships between the two eyes.

Animals↗

PubMed1990

The value of strabismus surgery.

Strabismus surgery is indicated for a variety of conditions stemming from misalignment of the eyes, abnormal head posture, and nystagmus. Although part of the value of such surgery lies in the fact that it improves appearance, it differs from cosmetic surgery, because, unlike the latter, it is designed to restore only normal configuration for ocular alignment--straight and/or aligned with the object of regard. A wide array of diagnostic tests are used to determine the precise treatment required, the goal of which is to provide comfortable vision, normal head position, and normal human appearance. In some cases nonsurgical techniques can be used to treat strabismus, but there is no evidence that visual training is an effective means of straightening eyes in those cases where surgery is considered the treatment of choice. For the most common strabismus, essential infantile or "congenital" esotropia, 80+% of infants have "straight" eyes after the initial operation, and 90% after a second operation, most of these with "straight eyes" have residual deviation of 5 prism diopters of esotropia or less. More than 50% of surgically treated patients have stable, long-term satisfactory results. Considering the effort required on the part of the ophthalmologist, together with the physical and psychological benefit to the patient, the cost of strabismus surgery should be equal to that of any major ophthalmic surgical procedure. That strabismus surgery is compensated at a lower rate, than for example, cataract surgery, suggests that strabismus surgery is an excellent value.

Cost-Benefit Analysis↗

PubMed1990

Jaw muscle tension after succinylcholine in children undergoing strabismus surgery.

The increases in tension at the masseter and adductor pollicis muscles following succinylcholine, 1 mg.kg-1, during halothane anaesthesia were measured in eight children, 3-10 yr, with strabismus. The results were compared with those obtained in a control group of general surgical patients. Supramaximal train-of-four (TOF) stimulation was applied to the ulnar nerve and the nerve to the masseter simultaneously. Jaw closure was measured by a force transducer system. In all patients, succinylcholine caused an increase in resting tone at the jaw and at the thumb. In the strabismus group, the magnitude of this increase was 55.7 +/- 23.2 g, mean +/- SD, at the jaw and 11.3 +/- 5.6 g at the thumb. This was not significantly different from the values obtained in controls, 45.3 +/- 33.4 g and 7.9 +/- 4.2 g, respectively. The duration of the phenomenon was 1-2 min in both muscles studied, and was not statistically different in the strabismus group. Time to complete neuromuscular blockade was significantly faster at the masseter, 31 +/- 6 sec--control groups; 39 +/- 11 sec--strabismus group, than at adductor pollicis, 61 +/- 34 sec--control groups; 75 +/- 28 sec--strabismus group (P less than 0.05 and 0.013 respectively). It is concluded that succinylcholine causes similar increases in jaw tension and comparable degrees of neuromuscular blockade in patients undergoing strabismus surgery as in other children.

Anesthesia, Inhalation↗

PubMed1989

An automated system of strabismus management. A direct approach using a "reverse" model.

Until now computer models of strabismus have consisted of lengthy calculations based on oculomotor physiology. Such models have been able to demonstrate the pattern of strabismus that would arise from any given muscle abnormality and/or operation. However, it has been difficult to use such models to guide strabismus surgery because the surgeon requires a model that works in the opposite direction. The surgeon requires a model whose input is the pattern of strabismus and output is the muscle operation required. Such a model is described here. Instead of consisting of calculations based on physiology the new model consists of a store of most of the information capable of being generated by an existing strabismus model together with an efficient search procedure. In this paper the potential of the new model is demonstrated by its application to a case of paralytic strabismus.

Diagnosis, Computer-Assisted↗

PubMed1983

[Strabismus and amblyopia. Value of their early detection].

The authors emphasize the importance of the relations between strabismus and amblyopia. Strabismus is often the symptom which leads to the discovery of amblyopia. Amblyopia may cause strabismus, as in organic amblyopias induced by congenital lesions of the retina or visual pathways, and visual deprivation amblyopias due to corneal opacities and/or congenital cataracts. Unilateral clouding of normally transparent media (cornea, lens, vitreum) prevents normal stimulation of the retina which is necessary to the development of binocular vision. Anisometropic amblyopias also belong to this category. More often, amblyopia is the consequence of strabismus: it is then termed "functional strabismic amblyopia". Loss of the parallelism of the two visual axes disrupts the functional balance between the images received from the two eyes. The two images are different; one is suppressed. This suppression may eventually lead to amblyopia. Amblyopia was discovered in 593 of 1 757 studied cases of strabismus. Amblyopia was the cause of strabismus in 87 patients and was functional in the remaining 506. Among these latter, visual acuity was inferior or equal to 1/10 in 241 cases and between 2/10 and 7/10 in 265. 147 children in the first group and 136 in the second could be treated. Among these patients, who were treated before the age of seven, complete recovery was obtained in approximately 1/2 of cases and improvement in more than 1/4 of first group patients and 1/3 of second group patients. Results were all the better that treatment was initiated earlier and that patients were younger.(ABSTRACT TRUNCATED AT 250 WORDS)

Amblyopia↗

PubMed1983

[Functional treatment of strabismus: theoretical bases--practical rules].

Functional treatment of strabismus is no longer empirical, but has currently a scientific basis. To disperse the "doubts" surrounding functional treatment, it appeared necessary to situate it more clearly within its true framework, that of functional re-education in general. Indeed, although the terrain differs adults with a lesion and children whose binocular function is poorly or only partially developed - in both cases: - functional recovery is the result of changes within the central nervous system, changes which are possible due to the plasticity of the central nervous system. These modifications occur very slowly, sometimes over a period of years. - The crucial condition for success of treatment remains the same: the patient must participate actively, this being all the more essential in that recovery will take a long time. Although strabismus treatment must obviously consider physiological parameters (triad), psychological parameters are just as important, and as well as purely technical problems, other factors must also be taken into account: subject's motivation, length of treatment, communication with the doctor and medical team, attitude of the patient's family. This type of therapy is only justified as long as strabismus is considered to be a dysfunction of binocularity (this however, does not exclude surgery in some cases, and the operation is an integral part of the treatment). Functional treatment of strabismus is therefore difficult and disconcerting for the practising ophthalmologist. Disconcerting in that it differs radically from other types of eye therapy (medical or surgical); difficult in that the restraint it imposes is often in contradiction with the permissive society we live in. One of the main obstacles to be overcome is perhaps our own judgement as ophthalmologists; our opinion of the nature of strabismus, the possibility of a cure, to which must be added the application of the right technique, patient participation, etc. This study attempts to situate strabismus within the general framework of functional re-education, employing different authors' opinions of basic notions of neurophysiology relating to nervous plasticity and their application in cases of cortical lesions in adults. In Part II we shall outline why and how we have opted for functional re-education. The reasons why and the manner in which functional re-education was chosen are then outlined.

Age Factors↗