Search PubMed⌕ Search

Biomedical subjects

Burton J Kushner

Publications and source records attributed to Burton J Kushner.

At least 19 recordsLinked to original sources
PubMed2006

Multiple mechanisms of extraocular muscle "overaction".

OBJECTIVE: To assign more specific pathophysiologic processes to the protean patterns of extraocular muscle "overaction" that we see in clinical practice. METHODS: By extrapolating from known principles of striated muscle physiology, a cohesive theory about extraocular muscle behavior is derived. RESULTS: The key to understanding apparent extraocular muscle overaction is to differentiate between a muscle that has decreased elasticity and one that is strengthened. Primary inferior oblique muscle overaction has the characteristics of a muscle that primarily has decreased elasticity, the superior rectus overaction/contraction syndrome appears to represent a muscle that is strengthened, and inferior oblique overaction secondary to ipsilateral superior oblique palsy has elements of both decreased elasticity and strengthening. Many motility patterns that appear to be due to an overacting muscle may in fact be caused by other muscles than the suspected one. CONCLUSION: Apparent extraocular muscle overaction can be caused by many different factors.

Humans↗
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↗
PubMed2006

Successful treatment of anisometropic amblyopia with spectacles alone.

BACKGROUND: The efficacy of treating anisometropic amblyopia with occlusion therapy is well known. However, this form of treatment can be associated with risks. Spectacle correction alone may be a successful and underutilized form of treatment. METHODS: The records of 28 patients treated successfully for anisometropic amblyopia with glasses alone were reviewed. Age, initial visual acuity and stereoacuity, and nature of anisometropia were analyzed to assess associations with time required for resolution, final visual acuity, and stereoacuity. Incidence of amblyopia recurrence and results of subsequent treatment, including patching, were also studied. RESULTS: Mean time to amblyopia resolution (interocular acuity difference <or=1 line) was 5.8 months (range 2 to 15 months). Worse best corrected initial visual acuity was associated with longer time to resolution (Spearman's rho = 0.37, P = 0.05), while age, initial stereoacuity, amount, and type of anisometropia were not (P = 0.43, 0.68, 0.26, 0.47, respectively). None of the astigmatic or myopic patients achieved visual acuity of 20/20 in the amblyopic eye, while seven (39%) of the hyperopic patients did. This difference was significant (P = 0.03). Better initial stereoacuity predicted good final stereoacuity (P = 0.01). Only four (14%) patients developed amblyopia recurrence over an average follow-up period of 1.7 years. All were successfully treated with updated spectacles or patching. CONCLUSIONS: Treatment of anisometropic amblyopia with spectacles alone can be a successful option. Patients treated with spectacles alone may experience a lower amblyopia recurrence rate than those treated with occlusion therapy.

Amblyopia↗
PubMed2005

A multi-disciplinary study of the ocular, orthopedic, and neurologic causes of abnormal head postures in children.

PURPOSE: To determine the relative frequency that abnormal head postures in children are caused by orthopedic, ophthalmologic, or neurologic disorders, respectively. DESIGN: A prospective, consecutive case series. METHODS: Children found to have an abnormal head posture on routine pediatric examination underwent an evaluation by a pediatric ophthalmologist, pediatric orthopedist, and pediatric neurologist. The study was conducted in northwestern Italy. RESULTS: In the 63 children evaluated, the cause of the abnormal head posture was orthopedic in 35, ocular in 25, and neurologic in 5. In 8 patients, no specific cause could be found. The most common orthopedic cause was congenital muscular torticollis, which accounted for 31 patients. The most common ocular cause was superior oblique muscle palsy, which accounted for 12 patients. In 2 patients neck muscle contracture suggested an orthopedic cause, however, the tight neck muscles were secondary to a head tilt caused by superior oblique muscle palsy. CONCLUSIONS: When the cause of an abnormal head posture is not obvious, a multi-disciplinary approach including ophthalmologic, neurologic, and orthopedic specialists may be helpful.

Child, Preschool↗
PubMed2005

Ocular complications after organ and bone marrow transplantation in children.

BACKGROUND: Organ and bone marrow transplantation commonly are performed in children. Ocular complications usually are described as secondary to post-transplantation medications. The complication rate is unknown. METHODS: A retrospective chart review was performed of 93 children who were younger than 18 years of age and had transplantation surgery from 1989 to 2004. The rate and type of ocular complications, including those requiring ocular surgery, were analyzed. Medications and visual loss associated with adverse effects also were studied. RESULTS: Of the 93 patients, 74 patients met the entry criteria. Sixty-one patients had at least 1 year of follow-up, and the longest follow-up duration was 14 years. The 1-year post-transplantation complication rate was 16.0% (95% confidence interval 6.8-24.4%). Adverse effects included cytomegalovirus (CMV) retinitis, cataract, graft-versus-host disease, lymphoproliferative disorder, persistent strabismus, and transient visual loss. Four patients underwent eye surgery, including lensectomy for cataract, tarsorrhaphy for corneal ulcer, and iris biopsy. They had surgery 0.9 to 4.7 years after transplantation. Most patients were taking prednisone and cyclosporine when their complication was diagnosed. One patient's visual acuity deteriorated to no light perception in one eye and 20/250 in the other eye secondary to CMV retinitis. Most patients had a final visual acuity > or =20/40. CONCLUSION: Transplantation surgery in children produces a significant risk of ocular impairment. The 1-year complication rate was 16.0%. Eye surgery may be required within the first few years after transplantation. Although most patients maintained a final visual acuity of 20/40 or better, one patient became bilaterally legally blind.

Adolescent↗
PubMed2004

Ocular torsion: rotations around the "WHY" axis.

BACKGROUND: Traditional teaching holds that there is a partial compensatory countertorsion after head tilt because the intorters in the eye on the side of the head tilt and the extorters in the contralateral eye are stimulated. This teaching is inconsistent with a number of clinical observations. METHODS: Review of existing literature, reanalysis of data from the investigator's previous experiments, and inductive and deductive reasoning were used to reconcile inconsistencies and present a theory on why torsional movements occur. RESULTS: The inconsistencies can be reconciled if one considers that during the dynamic phase of head tilt, there is an alternating series of intorsional and extorsional movements of both eyes. Each eye has slow dynamic compensatory counterrolling phases that serve as torsional "doll's-head" movements to stabilize the image during head tilt. This counterrolling is partially eliminated by a series of anticompensatory torsional saccades in the direction of head tilt, which is in contrast to traditional teaching. CONCLUSION: Dynamic compensatory counterrolling occurs during head tilt. It is largely eliminated by anticompensatory torsional saccades in the opposite direction so that by the end of head tilt only minimal static countertorsion remains. The dynamic compensatory counterrolling motion is necessary to minimize peripheral visual movement during head tilt. The elimination of most of the counterrolling by the end of head tilt is necessary to preserve convergence and stereopsis.

Convergence, Ocular↗
PubMed2004

An evaluation of the semiadjustable suture strabismus surgical procedure.

BACKGROUND: Muscle slippage is an adverse outcome of strabismus surgery. Its incidence is increased if adjustable sutures are used or if surgery is performed on the inferior or medial rectus muscles. Although there are no firm numbers for this complication, studies have suggested incidence rates between 7% and 41% when adjustable suture surgery is performed on the inferior rectus muscle. In theory, the semiadjustable suture procedure should decrease this adverse outcome. This procedure involves suturing the corners of the muscle firmly to the sclera and placing the center of the muscle on an adjustable suture. This study evaluates semiadjustable suture surgery with respect to muscle slippage. METHODS: The primary treatment group consisted of 57 patients who underwent semiadjustable suture surgery on a total of 61 muscles that either had never previously undergone surgery or had undergone surgery and had not previously slipped postoperatively. Fifty-five were inferior rectus muscles and 6 were medial rectus muscles. An additional 7 patients had semiadjustable suture surgery on muscles that had slipped after prior surgery and were analyzed separately. The outcome evaluation was at least 6 months after surgery. RESULTS: None of the 57 patients in the primary treatment group demonstrated muscle slippage after semiadjustable suture surgery. One of the 7 patients who had history of prior muscle slippage also had slippage after semiadjustable suture surgery. CONCLUSION: The semiadjustable suture procedure appears to decrease the incidence of muscle slippage.

Adolescent↗
PubMed2003

Diplopia after refractive surgery: occurrence and prevention.

OBJECTIVES: To report the occurrence of persistent diplopia manifesting after refractive surgery, to describe the different causes of this complication, to provide risk stratification for its occurrence, and to outline minimal screening techniques for its prevention. METHODS: A retrospective medical record review of patients seen in 2 private strabismus practices who experienced persistent diplopia after refractive surgery. RESULTS: A total of 28 patients were identified who met the inclusion criteria. The causes of postoperative diplopia could be traced to 1 of 5 mechanisms. These included technical problems, prior need of prisms, aniseikonia, iatrogenic monovision, and improper control of accommodation in patients with strabismus. The recommended screening techniques would have identified all patients in this series as being at risk for postoperative diplopia with the exception of those in whom technical problems were responsible. CONCLUSIONS: Diplopia can become manifest after refractive surgery. With proper attention paid to risk stratification and recommended screening criteria, the incidence of this complication can be minimized.

Adult↗