Biomedical subjects

David R Stager

Publications and source records attributed to David R Stager.

5 recordsLinked to original sources

PubMed2003

Anterior and nasal transposition of the inferior oblique muscles.

BACKGROUND: When performing anterior transposition of the inferior oblique (IO) muscle, placement of the posterior suture close to the lateral border of insertion of the inferior rectus (IR) muscle decreases the incidence of antielevation syndrome (AES). We hypothesized that placement of the suture nasal to the IR muscle insertion will convert the IO muscle into an intorter and depressor. Here we present the first series of results obtained with a new procedure for the treatment of elevation in adduction with extorsion and abnormal head postures. METHODS: Twenty patients with IO muscle overaction, superior oblique (SO) muscle palsy, absent SO muscles, AES, or Duane syndrome were studied. Before surgery, each patient showed at least one, but often more, of the following signs: elevation in adduction, exotropia (XT) in up gaze, abnormal head posture, and extorsion. Each underwent anterior and nasal transposition (ANT) of the IO muscle, with the new insertion typically 2 mm nasal and 2 mm posterior to the nasal border of the IR muscle insertion. RESULTS: Large improvements in ocular alignment, extorsion, and head posture were found in most patients. However, a poor result was noted in a patient with Y-pattern XT, who developed a mild amount of comitant XT after an extreme degree of ANT (4 mm nasal and 3 mm anterior to the nasal border of the IR muscle insertion). In Duane syndrome, ANT corrects upshoot, but downshoot may get worse. Mersilene permanent sutures, rather than dissolving suture materials, are recommended to avoid postoperative retraction of muscle fibers. CONCLUSIONS: ANT converts the IO muscle into an intorter and tonic depressor and can significantly improve elevation in adduction. This procedure seems particularly useful in patients with severe or recurrent congenital and acquired SO palsies, particularly as a secondary procedure. Extreme ANT may induce exotropia in the primary position.

Adolescent↗

PubMed2003

The management of strabismus in adults--I. Clinical characteristics and treatment.

INTRODUCTION: This is the first in a series of articles intended to evaluate the management of strabismus in adults, including clinical outcomes and the quality, cost, and value of treatment from the perspectives of patients and health care providers. Here we present clinical characteristics, complexity of surgery, treatment success, and resolved complaints in a group of adult patients who underwent strabismus surgery. METHODS: This is a multicenter retrospective study analyzing the type and amount of ocular misalignment before and after surgery in adult patients with strabismus onset before (BVM, or age < 9 years) or after (AVM, or age >/= 9 years) visual maturation. Success was evaluated in terms of alignment, motility, and the presence of diplopia; subjective success was measured in terms of resolved complaints. The complexity of surgery was determined using the Intensity/Complexity Index and compared with success rates. RESULTS: Data are reported on 299 patients (90 BVM and 145 AVM) whose eyes were successfully aligned in 63% of the BVM cases and 81% of the AVM cases. Subjective complaints resolved at similar rates in the BVM and AVM subgroups. Successful alignment was not correlated with complexity of surgery, but motility and sensory success rates were correlated with complexity of surgery. CONCLUSION: Within each of the BVM and AVM subgroups, this study of adult strabismus showed similar surgical success rates compared with published data. This qualifies these patient groups as clinically typical of adults undergoing strabismus surgery. Additional studies will expand on health value analyses.

Adolescent↗

PubMed2002

Risk factors for the development of accommodative esotropia following treatment for infantile esotropia.

PURPOSE: One aim of the study was to determine whether accommodative esotropia after surgical alignment in infantile esotropia occurs because a pre-existing accommodative component is unmasked at the time of surgery or whether it occurs as a sequela of infantile esotropia. A second aim of the present study was to examine risk factors for accommodative esotropia after surgery for infantile esotropia. METHODS: A total of 80 consecutive patients who were enrolled in a prospective study of infantile esotropia had been followed for more than 4 years and had achieved orthoposition were included. Twelve potential risk factors were examined: age at onset, initial esodeviation, initial refractive error, age at alignment, delay in alignment, presurgical glasses, amblyopia, additional surgical procedures, unstable alignment, increase in hypermetropia, peripheral fusion, and stereopsis. Mantel-Haenszel odds ratios were computed for each factor and were corrected to relative risks. RESULTS: Overall, 48 of 80 children (60%) developed accommodative esotropia at a mean age of 33 months. Increasing hypermetropia, delay in alignment, and poor stereopsis posed significant risks for accommodative esotropia. The remaining 9 factors were not associated with increased risk for accommodative esotropia. CONCLUSIONS: Accommodative esotropia is unlikely to be a pre-existing condition in most cases because the mean age of onset was 23 months postoperative and the prevalence of preoperative hypermetropia greater than +3.00 D was low. Both delay in alignment and stereopsis risk factors may reflect compromised binocular sensory status that allows accommodative esotropia to occur at low to moderate levels of hypermetropia. Identification of children treated for infantile esotropia who are at risk for accommodative esotropia may allow for prevention or early treatment.

Accommodation, Ocular↗

PubMed2002

Preschool Worth 4-Shape test: testability, reliability, and validity.

PURPOSE: The Worth 4-Dot is used to assess binocular fusion, but it is difficult to use with young children. We modified the Worth 4-Dot by replacing the circles with shapes while maintaining the same color configuration. The purpose of this study was to determine the testability, reliability, and validity of the Worth 4-Shape test. METHODS: Subjects aged 2 to 8 years and 4 patients aged over 8 years with best-corrected visual acuity of 20/40 or greater (n = 131 patients, n = 123 normals) attempted test and retest at 35 cm and 3m using the Worth 4-Shape and Worth 4-Dot. To provide a gold standard, medical history, bifoveal fixation, and stereoacuity were reviewed. RESULTS: Testability of the Worth 4-Shape was significantly higher than the Worth 4-Dot both in children aged less than 4 years (95.9% vs 79.5% at 35 cm, P <.001; 79.5% vs 55.1% at 3 m, P <.001) and older than 4 years (98.5% vs 88.6% at 35 cm, P <.001; 90.9% vs 82.4% at 3m, P =.04). Test-retest analysis found comparable concordance for the Worth 4-Shape and Worth 4-Dot tests (P >.3). The sensitivity and specificity of the Worth 4-Shape (92%, 97%) and Worth 4-Dot (90%, 94%) were comparable. Between-test analysis found 96% agreement between both tests at 35 cm and 97% agreement at 3m. CONCLUSIONS: The success rate for the Worth 4-Shape is higher than the Worth 4-Dot, especially in children aged less than 4 years, and has equivalent accuracy. The Worth 4-Shape test-retest reliability is high supporting its validity for use with young children.

Child↗

PubMedDate not supplied

Long-term rates of PCO following small incision foldable acrylic intraocular lens implantation in children.

PURPOSE: To evaluate the long-term incidence of postoperative posterior capsular opacification (PCO) in children undergoing small incision foldable acrylic lens implantation with at least 2 years of follow up. METHODS: In 18 children, 26 eyes underwent small incision cataract extraction with posterior chamber foldable acrylic lens implantation. The posterior capsule was left intact in all patients at the time of surgery. RESULTS: With a mean follow up of 2.75 years and a mean age at surgery of 8.25 years, 13 of 26 eyes (50%) developed visually significant PCO requiring intervention. In the group of children under 4 years of age, 5 of 5 eyes (100%) developed visually significant PCO, while 8 of 21 eyes (38%) in the group of children over 4 years of age developed opacification. Four of 26 eyes (15%) required two procedures (either repeat Nd:YAG laser capsulotomy or pars plana secondary membrane removal) to clear the visual axis. CONCLUSION: In this study, the incidence of PCO following small incision acrylic lens implantation in children over 4 years of age is lower than those rates reported by conventional large incision rigid lens techniques with a minimum of 2 years follow up. This technique has advantages over conventional techniques in older children because it offers less surgical intervention, a lower cost to patients, and less risk of vitreous and retinal complications.

Acrylic Resins↗