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PubMed1984

[Accommodation in strabismus].

This paper describes clinical observations of optico-sensori-motor symptomatology prior to and during treatment for strabismus. These findings were compared with theoretical data of the binocular visual function. We consider that binocular function has the structure and the working of a "set" in cybernetic sense. In this psycho-physiological set, the accommodative system constitutes a "sub-set". The classification of accommodative disturbances as "pure or impure" and "typical or atypical" arises from the fact that a rebuilding of the visual function has occurred. Thus in "pure" accommodative strabismus the disturbances of accommodation results from "peripheral" accommodation and is easily reversible. In this situation ocular deviation has been perfectly corrected for and binocular vision normally built up since there is enough compensation of the whole optical correction. In "impure" accommodative strabismus the perturbation of accommodation affects the whole accommodation system and also the sensorial motor system. Thus there is a restructuring of the optico-sensori-motor set that is more or less reversible due to a variety of factors. From these investigations we conclude: every strabismus is accommodative in the sens that in every strabismus there is a disturbance of accommodative mechanism. Furthermore, we oppose believers of "all sensorial" and "all motor" mechanisms. Considering that strabismus is a disturbance of optico-sensori-motor binocularity, nothing can be only "accommodative", only "sensorial" and only "motor". From this it follows that treatment should not be only "motor", only "accommodative" or only "sensorial".

Accommodation, Ocular↗

PubMed1994

[Treatment of paralytic strabismus].

1) Cases of strabismus combined with abnormalities in ocular movement were divided into three groups: paralytic nonconcomitant strabismus, special forms of strabismus, and paralytic concomitant strabismus. 977 cases of surgery for paralytic nonconcomitant strabismus were analyzed. 2) 109 cases of surgery for paralytic esotropia due to abducens palsy were performed. In cases of complete paralysis, a transposition of the vertical rectus muscle was indicated. In cases of incomplete paralysis, a resection of the lateral rectus muscle was indicated. On the basis of these indications, the same results could be achieved, and when a recession of the medial rectus muscle was concurrently performed the results were improved. 3) In oculomotor palsy, 138 cases of surgery for paralytic exotropia were performed. In cases of complete paralysis, a transposition of the superior oblique muscle was indicated. In cases of incomplete paralysis, a resection of the medial rectus muscle was indicated. On the basis of these indications, the same results could be achieved, and when a recession of the lateral rectus muscle was concurrently performed the results were improved. 4) 570 cases of surgery for superior oblique muscle palsy were performed. In cases of vertical deviation, a weakening operation on the inferior oblique muscle, the superior rectus muscle of the affected eye, and the inferior rectus muscle of the sound eye were indicated. In cases of torsional deviation, good results were obtained through an advancement of the anterior part of the superior oblique muscle and a resection of the superior oblique muscle. 5) Statistics concerning cure based on the standards for cure employed by the Japanese Association of Strabismus and Amblyopia, or from the point of view of cosmetic cure were: 85% for paralytic esotropia and superior oblique muscle palsy, 82% satisfactory for incomplete paralysis of the oculomotor nerve within paralytic exotropia, and 61% relatively unsatisfactory for complete paralysis of the oculomotor nerve within paralytic exotropia. 6) The results of 216 cases examined after period of four years or longer were: cases where a one-month postoperative cure or cosmetic cure was maintained over this period were 90% of superior oblique muscle palsy cases, 79% of paralytic esotropia, and 59% of paralytic exotropia. Paralytic exotropia showed poor results. The surgical methods were muscle transposition in cases of horizontal muscle surgery and surgery of the oblique muscles in cases of vertical muscle surgery. 7) Through the Turn-Amplitude Analysis of the amounts of EMG interference patterns in the extraocular muscle, neuropathy was classified as either complete or incomplete.(ABSTRACT TRUNCATED AT 400 WORDS)

Child, Preschool↗

PubMed1994

Optometric management of strabismus patients.

BACKGROUND: The management of strabismic patients varies within the eye care profession. This paper provides an overview of strabismus; including etiology, diagnosis and therapeutic options. Implications as to the efficacy of different therapy strategies for strabismus are discussed. METHODS: A literature review of strabismus is presented and a sequence of therapeutic options is offered. RESULTS: A diagnostic battery of tests to evaluate the strabismus patient is reported along with therapeutic options. The basic assumption made in this paradigm is that one should move from a least invasive and therefore more safe, to a more invasive protocol, if necessary. The ultimate objective of any strabismic therapy should be to develop or restore effective binocular function, efficiency of vision and comfort, as well as cosmesis. CONCLUSIONS: In most cases, optometric therapeutic procedures should be the beginning treatment of choice in strabismus. It has been demonstrated in the literature that optometric therapy is less invasive and as successful as surgery in many cases of strabismus.

Optometry↗

PubMed1993

Egocenter location in children with strabismus: in the median plane and unchanged by surgery.

PURPOSE: Previous studies have shown that there are spatial localization shifts after horizontal strabismus surgery when a patient performs an open-loop pointing task. After monocular enucleation, an adult will also show a shift in the pointing response. Other studies have shown that in children who underwent enucleation, the egocenter location shifts toward the remaining eye. Is the pointing shift after surgery in children with strabismus the result of a shift in egocenter location? METHODS: Using a modified Roelofs' method for measuring the egocenter, eight children were tested before and after horizontal strabismus surgery to see if there were any shifts in egocenter location. One control group consisted of six children undergoing surgery for correction of vertical strabismus in which the horizontal muscles would be unaltered. RESULTS: Presurgery measurements of egocenter location in the people with strabismus were the same as those found in the other control group of 12 normal children. Postsurgical measurements of eye position showed horizontal rotations of 14.5 degrees for the horizontal group and 2.4 degrees for the vertical group. Egocenter measurements showed no postoperative shift for either strabismus group. CONCLUSIONS: Thus, the pointing shift seen in the previous studies is not from a shifting egocenter location but from a change in the registered position of the eye in the orbit.

Child↗

PubMed1998

[Own experience with the use of adjustable sutures in various types of strabismus operations].

PURPOSE: To present our results of operations in various types of strabismus conducted with the use of adjustable sutures. MATERIAL AND METHODS: We studied 56 patients, both adolescents and adults, aged between 15 and 57 years operated due to strabismus in Department of Ophthalmology, Medical University of Lódz. Adjustable strabismus sutures serve to improve the chance of achieving the desired surgical alignment with single operation and thereby decrease the need for staged operations or reoperations. RESULTS AND CONCLUSIONS: The surgery results were as follows: 60.8% excellent, 21.4 good, 14.3% fair, 3.3% poor. Five patients with various types of strabismus treated with the use of adjustable sutures were described. Adjustable sutures are a very good method for reoperation, in paretic strabismus, and also in adults when a good cosmetic result is desired after strabismus operation without the fear of diplopia.

Adolescent↗

PubMed2003

Divergent strabismus fixus--a case report.

Strabismus fixus is a rare condition and usually is of convergent type in which one or both eyes are anchored in a position of extreme adduction. Convergent type strabismus fixus is considered to be a congenital disorder and a part of congenital extraocular muscle fibrosis syndrome. Villasecca and Martinez described an acquired type of strabismus fixus. Hayashi et al reported that progressive esotropia could develop into the acquired type of convergent strabismus fixus. There are very few reports of divergent strabismus fixus in the literature. It may or may not be accompanied by ptosis or generalized extraocular muscle fibrosis. In our report, a case of divergent type strabismus fixus is described and discussed.

Aged↗

PubMedDate not supplied

Sensory strabismus--eso or exo?

PURPOSE: The type of horizontal strabismus from loss or impairment of vision is thought to depend on patient age at the time of vision loss. Association between the age at onset of vision loss and development of esotropia vs exotropia will be determined. METHODS: Patients with a diagnosis of sensory strabismus and visual acuity of 20/40 or poorer were reviewed as well as patients with diagnoses consistent with the development of sensory strabismus. Parameters considered were age at onset of vision loss and type of strabismus. Patients were excluded if the age at onset was not clear. RESULTS: Of 123 patients with sensory strabismus reviewed: 82 (67%) had unilateral vision loss; 41 (33%) had bilateral vision loss; 75 (61%) had congenital vision loss; 50 (67%) developed esotropia; 25 (33%) developed exotropia; 48 (39%) had acquired vision loss; 5 (10%) developed esotropia; and 43 (90%) developed exotropia. A significant difference was noted between age at onset and type of horizontal strabismus (X2= 37.44; P <.0001). CONCLUSION: Of patients with congenital vision loss, 67% developed sensory esotropia and 33% developed sensory exotropia. Of those with acquired vision loss, 10% developed sensory esotropia and 90% developed sensory exotropia. Patients with congenital vision loss are significantly more likely to develop esotropia, P <.005, and those with acquired vision loss are significantly more likely to develop exotropia, P <.001.

Age of Onset↗

PubMed2002

Strabismus in children of birth weight less than 1701 g.

OBJECTIVE: To prospectively study infants of birth weight less than 1701 g in the East Midlands of England in the mid 1980s at 10 to 12 years of age to determine the incidence and risk factors for strabismus in children born preterm. METHODS: Low-birth-weight children (n = 572) who had been examined during the neonatal period were invited for a follow-up visit at age 10 to 12 years; 169 eleven-year-old schoolchildren born at full term were also recruited (the school cohort). RESULTS: Of the original 572 children, 293 consented to further examination. There was no significant difference between children who were examined and those who were not in terms of birth weight, gestational age, retinopathy of prematurity, and cranial ultrasound abnormalities. Compared with the school cohort (n = 5 [3.0%]; 95% confidence interval, 1.0%-9.1%), the low-birth-weight cohort had a significant increase in the prevalence of strabismus (n = 59 [20.1%]; 95% confidence interval, 15.9%-25.0%; P<.001). Compared with published data, there was a relative increase in the occurrence of exotropia in the low-birth-weight study cohort. Multivariate analysis, by backward logistic regression, indicated that retinopathy of prematurity, birth weight, cerebral palsy, anisometropia, and refractive error were all independently associated with strabismus (P<.05). CONCLUSIONS: The results of this study confirm the increased prevalence of strabismus in a low-birth-weight population. This study also provides more detailed information on risk factors and strabismus types.

Child↗

PubMed2006

Perspective on strabismus, 2006.

During the last half of the 20th century, the field of strabismus did not undergo as many major advances as other areas of ophthalmology. In recent years, an increase in basic science research has fostered important advances in our understanding and treatment of disorders of binocular vision. This article identifies 4 important questions that need to be addressed by the pediatric ophthalmology and adult strabismus community: (1) What terms should be used to describe muscle dysfunction? (2) By what mechanism does strabismus surgery work? (3) What is the role of orbital imaging in the management of strabismus? (4) What is the role of refractive surgery in the treatment of patients with amblyopia and strabismus?

Adult↗

PubMed1992

Maternal cigarette smoking during pregnancy. A risk factor for childhood strabismus.

Strabismus is a common ophthalmologic disorder in children that can result in permanent visual loss. A population-based case-control study was conducted to investigate the association between childhood strabismus and prenatal risk factors including maternal smoking. All incident cases of strabismus diagnosed during a 21-month period, from January 1, 1985, to September 30, 1986, in nine metropolitan area pediatric ophthalmology centers were selected for study (n = 377). Controls were children born on the same day and in the same hospital as the cases (n = 377). Data collection included an interview with the biologic mother and abstraction of obstetric and neonatal birth records. Cigarette smoking was associated with esotropia and but not exotropia for those women who smoked throughout pregnancy (odds ratio, 1.8, 95% confidence interval, 1.1 to 2.8, and odds ratio, 1.4, 95% confidence interval, 0.6 to 3.1, respectively). The relative risk for strabismus was not elevated for women who quit smoking before pregnancy or during pregnancy, nor was there evidence of a dose response. The effect of maternal smoking on risk of esotropia was modified by birth weight and gestational age. The association of maternal smoking throughout pregnancy and esotropia was strongest for children who weighed less than 2500 g (odds ratio, 8.2, 95% confidence interval, 1.1 to 62.7) and 3500 g or more at birth (odds ratio, 5.6, 95% confidence interval, 2.1 to 15.4). Exposure to secondary smoke during pregnancy increased the risk of strabismus only when the mother smoked.

Baltimore↗

PubMed1982

Binocularity in comitant strabismus: binocular visual fields studies.

A critical review is made of the literature on binocular perimetry in strabismus. A broad range of results was obtained by various authors, because different testing techniques were used. The concept of sensory testing of strabismic patients in casual seeing condition should be introduced also into binocular perimetry. Therefore a series of experiments is presented in which patients with small-angle comitant strabismus were tested. It was shown that: a) in small-angle esotropia the areas of single vision previously thought to be due to suppression are, instead, areas of binocular vision sustained by anomalous retinal correspondence (ARC); b) this can be seen only when using fusable stimuli as test targets; c) no suppression scotomas were found in patients with small-angle strabismus in the whole visual field; d) appropriate control-marks for binocularity are necessary, i.e. monocularly presented items. They influence the results, as well e) the area of binocular single vision in strabismus (called pseudo-Panum's area) is wider than the Panum's area of normals. Moreover it is easier to disrupt binocular cooperation sustained by ARC causing diplopia than binocular cooperation in normals; f) ARC seems to be more deeply rooted in the center than in the periphery of the visual field; g) superimposable findings were obtained in small-angle constant exotropia; h) in large-angle exotropia wide suppression scotomas were found, which often override the midline. Hemianopic suppression scotomas in exotropia can be found only when 'dissociating' testing techniques are used; i) the same group of patients with small-angle esotropia was examined with the author's technique and with the classical method proposed by Harms. The results were strongly dependent on the method used and the same patient responded differently to the two tests. It is concluded that in small-angle strabismus there is an anomalous type of binocular single vision, which can be tested with binocular visual field techniques. This binocularity can only be found when non-artificial testing conditions are used. The usefulness of this anomalous binocular vision in the every day seeing condition of the patient is discussed.

Depth Perception↗

PubMed1988

Central motor control in concomitant strabismus.

Basic research in the field of oculomotor physiology has advanced rapidly during the last decade. The new knowledge has been largely incorporated into the research and the clinical practice of neurology and neuroophthalmology [14, 16], but the influence on strabismus research has been rather limited [15]. This presentation will point out the elements of basic research that are believed important for our understanding of concomitant strabismus. The description will concentrate on the role of different central motor factors, mainly brainstem mechanisms, in the genesis and development of infantile esotropia or convergent strabismus, i.e. strabismus with an early onset in life [8]. Strabismus of late onset seems less enigmatic, since it probably originates from abnormalities of the vergence system, particularly its coupling with accommodation.

Accommodation, Ocular↗

PubMed1999

[Strabismus and diplopia as complications after cataract surgery with IOL implantation].

UNLABELLED: In our Department of Orthoptics we have seen an increasing number of patients suffering from diplopia after cataract surgery with IOL implantation. Between 1993 and 1997 the total number of patients with this problem was 24 (2.7 % of all patients, mean age 71 years, age range 38-88). We addressed the question of whether there is a common pattern of motility dysfunction. METHODS: After evaluation of the clinical history and the basic ophthalmological findings the following parameters were examined: binocular function (Bagolini test), squint angles (Maddox cross), ocular motility. RESULTS: The 24 patients could be divided up into three groups. Group 1 consisted of 9 patients (mean age 82 years, range 64-88) who complained about diplopia because of strabismus incomitans with vertical deviation and restricted motility on the first day after surgery. In 8 of the 9 patients strabismus surgery was done. Group II consisted of 10 patients (mean age 66 years, range 38-77) who noticed diplopia and strabismus within 7 days after surgery. We found various kinds of heterotropia. Seven of these patients were operated on and two had a prism correction. Group III consisted of 5 patients (mean age 67 years, range 61-78). Their already known strabismus paralyticus or concomitans deteriorated, leading to diplopia in some cases. All patients in this group were operated on. DISCUSSION: For group I we believe that retro-, para- or peribulbar anesthesia caused the motility dysfunction. In groups II and III it is unlikely that local anesthesia had a causative role. The prolonged disruption of binocular vision and the abrupt change in the sensory situation after the cataract operation with lens implantation may be the leading causes for strabismus or deterioration of a preexisting strabism, respectively. CONCLUSIONS: These patients need a subtil meticulous diagnostic work-up and follow-up because of the possibility of early surgical therapy, which has a good prognosis. Evaluation of binocular vision and eye movements prior to cataract surgery appears to be helpful for later strabismic surgery.

Adult↗

PubMed1981

Dyskinetic strabismus as a sign of cerebral palsy.

We found dyskinetic strabismus in 66 patients with cerebral palsy. The most striking feature of dyskinetic strabismus is the fluctuation from esotropia to exotropia under the same accommodative conditions with a slow tonic deviation similar to a vergence movement. With increasing age, exodeviation becomes more prevalent. Dyskinetic strabismus is seen exclusively in cerebral palsy patients. Many of these patients have an athetoid component to their disorder. The association of dyskinetic strabismus with athetosis and upward gaze palsy suggests that the basal ganglia may be the site of the malfunction. The strabismus responds poorly to surgery and the associated athetosis is important in the diagnosis and treatment of cerebral palsy.

Adolescent↗

PubMed1995

The effects of oral droperidol versus oral metoclopramide versus both oral droperidol and metoclopramide on postoperative vomiting when used as a premedicant for strabismus surgery.

STUDY OBJECTIVE: To compare the efficacy of oral droperidol versus oral metoclopramide, or both oral droperidol and metoclopramide, on postoperative vomiting when used as a premedicant for strabismus surgery. DESIGN: Double-blind, randomized, prospective study. SETTING: Academic children's hospital. PATIENTS: 154 ASA physical status I and II ambulatory patients, ages 1 to 15 years, scheduled for strabismus surgery. INTERVENTIONS: Patients were randomly assigned to receive colored sugar water containing either droperidol 300 mcg/kg orally, metoclopramide 0.15 mg/kg orally, both droperidol 300 mcg/kg and metoclopramide 0.15 mg/kg orally, or no active ingredient (placebo group) as a premedicant. The premedications were given orally 1 to 1.5 hours prior to the operation. MEASUREMENTS AND MAIN RESULTS: Patients were analyzed for the number of episodes of vomiting from the time of their emergence from anesthesia through the first 24 hours postoperatively, including the convalescent period at home. Patients were also analyzed for length of hospital stay. There were no statistically significant differences between groups regarding age, premedication time, surgery time, or discharge time. Droperidol and droperidol-metoclopramide were significantly more effective (p < 0.012) than either the metoclopramide group or the placebo group in preventing postoperative nausea and vomiting following strabismus surgery. CONCLUSIONS: Our data suggest that oral droperidol 300 mcg/kg and the combination of oral droperidol 300 mcg/kg and metoclopramide 0.15 mg/kg are effective in reducing the frequency of vomiting within the first 24 hours after strabismus surgery. The combination of oral droperidol and oral metoclopramide is highly effective in reducing the frequency of vomiting postoperatively in strabismus ambulatory surgery patients (p = 0.017). This combination seems to represent an inexpensive alternative to the more costly ondansetron.

Administration, Oral↗

PubMed2006

Giant orbital cysts after strabismus surgery.

PURPOSE: To describe a rarely reported complication of strabismus surgery. DESIGN: Observational case series. METHODS: A review of four eyes in three patients with orbital cysts following strabismus surgery. RESULTS: Each patient had either a symptomatic strabismus or visible mass that brought them to medical attention many years, often decades after surgery (mean 34 years). All had some degree of incomitancy. During surgery, all cysts were found to be associated with the involved rectus muscle. CONCLUSIONS: Orbital cysts are a rarely recognized complication of strabismus surgery. However, it should be considered in the differential of orbital cysts after strabismus surgery because of the risk of muscle damage during surgical excision.

Adult↗

PubMed2003

The threshold for the detection of strabismus.

PURPOSE: To identify the threshold at which horizontal or vertical strabismus becomes reliably detectable by observers and to determine the effects of interpupillary distance, age, gender, and observer experience. METHODS: Six models of different gender, age, and interpupillary distance were digitally photographed in several predetermined gaze positions off-axis in the horizontal and vertical planes. Standardized distance, zoom factor, and lighting were used. The images were digitally altered to exactly superimpose one eye deviated and one eye aligned with the axis of the camera. This simulated horizontal and vertical strabismus ranged from 2.5 to 20 prism diopters (PD). The images were arranged in random order and presented to groups of lay and professional observers, and their responses were recorded. RESULTS: The statistically significant threshold for detecting esotropia, exotropia, and hypertropia was 12.5 PD. Hypotropia had a higher threshold of 20 PD. Observer experience and model age each had a significant effect on the ability to detect strabismus. CONCLUSION: Our study demonstrates a unique method for assessing the significance of different types and degrees of strabismus. Our findings may be used to help patients with strabismus as they consider others' perception of their ocular misalignment. Physicians can also use this information in making decisions regarding surgery.

Adult↗

PubMed2005

Suppression of metabolic activity caused by infantile strabismus and strabismic amblyopia in striate visual cortex of macaque monkeys.

INTRODUCTION: Suppression is a major sensorial abnormality in humans and monkeys with infantile strabismus. We previously reported evidence of metabolic suppression in the visual cortex of strabismic macaques, using the mitochondrial enzyme cytochrome oxidase as an anatomic label. The purpose of this study was to further elucidate alterations in cortical metabolic activity, with or without amblyopia. MATERIALS AND METHODS: Six macaque monkeys were used in the experiments (four strabismic and two control). Three of the strabismic monkeys had naturally occurring, infantile strabismus (two esotropic, one exotropic). The fourth strabismic monkey had infantile microesotropia induced by alternating monocular occlusion in the first months of life. Ocular motor behaviors and visual acuity were tested after infancy in each animal, and development of stereopsis was recorded during infancy in one strabismic and one control monkey. Ocular dominance columns (ODCs) of the striate visual cortex (area V1) were labeled using cytochrome oxidase (CO) histochemistry alone, or CO in conjunction with an anterograde tracer ([H 3 ]proline or WGA-HRP) injected into one eye. RESULTS: Each of the strabismic monkeys showed inequalities of metabolic activity in ODCs of opposite ocularity, visible as rows of lighter CO staining, corresponding to ODCs of lower metabolic activity, alternating with rows of darker CO staining, corresponding to ODCs of higher metabolic activity. In monkeys who had infantile strabismus and unilateral amblyopia, lower metabolic activity was found in (suppressed) ODCs driven by the nondominant eye in each hemisphere. In monkeys who had infantile esotropia and alternating fixation (no amblyopia), metabolic activity was lower in ODCs driven by the ipsilateral eye in each hemisphere. The suppression included a monocular core zone at the center of ODCs and binocular border zones at the boundaries of ODCs. This suppression was not evident in the monocular lamina of the LGN, indicating an intracortical rather than subcortical mechanism. CONCLUSION: Suppression of metabolic activity in ODCs of V1 differs depending upon whether infantile strabismus is alternating or occurs in conjunction with unilateral amblyopia. Our findings reinforce the principle that unrepaired strabismus promotes abnormal competition in V1, observable as interocular suppression of ODCs.

Amblyopia↗