Biomedical subjects

Natalie C Kerr

Publications and source records attributed to Natalie C Kerr.

8 recordsLinked to original sources

PubMed2004

Fat adherence syndrome: an animal model.

BACKGROUND: Fat adherence syndrome (FAS) is a permanent restrictive strabismus that can occur after periocular surgery or trauma. The pathophysiology is poorly characterized. METHODS: Under varying conditions, fat autografts were secured with dissolvable sutures between the inferior rectus and the periosteum of the inferior orbital rim in both eyes of 15 New Zealand white rabbits. Sutures without fat autografts were placed in both eyes of three control rabbits. The force required to move the eyeball superiorly 4, 6, or 8 mm was measured with a digital strain gauge preoperatively and 6 weeks after surgery. Twelve of the 15 rabbits with autografts were then sacrificed, and exenteration specimens were taken. The three remaining rabbits (six eyes) were observed for 6 months after placement of fat autografts. RESULTS: Analysis of variance allowed rejection of the null hypothesis that there was no difference among the postsurgical groups for all deflection points when 6 weeks postoperative was compared to baseline (preoperative) measurements (P < or = 0.05). Regression analyses showed that stiffness at each deflection was dependent on the amount of fat placed in the orbit. In three rabbits observed for 6 months, restriction tended to be stable over the 6-month observation period and was not alleviated by lysis of adhesions or removal of the fat grafts. CONCLUSION: A fat autograft introduced into an extraocular wound in rabbits will produce a permanent restrictive strabismus. This model may prove useful in the study of FAS.

Adipose Tissue↗

PubMed2004

Brown's Syndrome in the absence of an intact superior oblique muscle.

Brown's Syndrome was initially described as a superior oblique tendon sheath syndrome-a short anterior tendon resulting in a restricted elevation of the globe in the nasal field. Brown believed that a congenital paralysis of the inferior oblique muscle resulted in this secondary shortening of the anterior sheath of the superior oblique tendon. The definition of Brown's Syndrome has changed over time. It is currently defined as the inability to elevate the eye in the adducted position, both actively and passively on force duction testing, and can be acquired. The pathophysiology of acquired Brown's Syndrome may involve an abnormality of the superior oblique trochlea/tendon complex. However, it may also result from other causes unrelated to the superior oblique tendon or muscle, such as tumors of the superior nasal orbit, inferior orbital mechanical restriction, or an inferiorly displaced lateral rectus muscle and pulley. We present two cases in which a Brown's Syndrome was diagnosed after the superior oblique muscle had been disinserted or removed.

Adult↗

PubMed2004

Vision screening for children: current trends, technology, and legislative issues.

PURPOSE OF REVIEW: The purpose of this review is to examine current trends in vision screening for children. RECENT FINDINGS: Literature within the past year regarding children's vision screening has been dominated by clinical validation studies of autorefractors or photoscreeners that allow the detection of amblyogenic refractive errors, misalignment of the eyes, or media opacities. New technologies reported include wave-front analysis for amblyogenic factors and a visual evoked potentials-based screening tool for the preverbal child. Studies evaluating the goals of the screening program, the target population, and the physical limitations of the screening environment have prompted multipronged or hybrid studies designed to more accurately detect vision problems, particularly in the preschool child, in whom cooperation and cognitive development affect reliability of results. State and federal legislation in the United States has been proposed or adopted to regulate and partially fund pediatric vision screening and comprehensive examinations. SUMMARY: Through improvements and new developments in technology, study design, the efforts of organized medicine, and legislative initiatives, vision screening for children continues toward the goal of bringing all children with eye disease or vision problems to treatment in a timely fashion.

Child↗

PubMed2003

Traumatic hyphemas in children secondary to corporal punishment with a belt.

PURPOSE: To report the severity of ocular injury in seven children with traumatic hyphemas resulting from the accidental striking of the child in the face with a belt during the administration of corporal punishment. DESIGN: Observational case series. METHODS: We retrospectively reviewed the records of all patients (n = 7, aged 4 to 14 years) with traumatic hyphemas secondary to belt injuries evaluated by the senior author between 1989 to 2002 at Le Bonheur Children's Medical Center, a regional pediatric referral hospital in Memphis, Tennessee. RESULTS: Anterior segment injuries ranged from small hyphemas with normal intraocular pressure and no vision loss to injuries with severe elevations of intraocular pressure and permanent, significant loss of vision. CONCLUSIONS: Ocular injury to a child can result from trauma inflicted with a belt by a parent or caretaker during corporal punishment and may result in permanent loss of vision.

Adolescent↗

PubMed2002

Visual evoked potentials in children with neurofibromatosis type 1.

The purposes of this investigation were to determine: (a) if visual evoked potential (VEP) abnormalities could be identified in children with neurofibromatosis type 1 (NF1) with no evidence of optic pathway or brain neoplasias on MRI; and (b) if VEP abnormalities could be explained by the presence of hyperintense T2-weighted foci on MRI testing, known as unidentified bright objects (UBOs). To answer these questions, VEPs were recorded from 16 children with NF1 and compared to 13 normal subjects in the same age range tested with the same protocol. Pattern-reversal VEPs were recorded at four stimulus sizes both monocularly and binocularly, the latter to hemi-field stimuli. Flash VEPs were recorded in dark- and light-adapted conditions. VEP measurements and MRI readings for UBOs were conducted in a masked fashion. Ten of the 16 children with NF1 had abnormal VEPs to at least one of the four types of stimuli. Abnormalities included delayed responses (n=6), absent flash VEP P2 component (n=3), or both (n= 1). Abnormalities of the P2 component of the dark-adapted flash VEP were the most common finding (n=7), although no single testing strategy was able to identify all children with abnormal VEPs. UBOs were present in all children, demonstrating that their presence does not fully account for VEP abnormalities in children with NF1. This study also demonstrates that VEP abnormalities are present also in the absence of neoplasias of the optic pathways or of the brain. Our results are suggestive of a primary abnormality of visual processing in children with NF1.

Adolescent↗

PubMed2002

Bilateral ametropic functional amblyopia in genetic ectopia lentis: its relation to the amount of subluxation, an indicator for early surgical management.

To determine the visual results of conservative (non- surgical) therapy, we reviewed all our patients with genetic ectopia lentis, with and without Marfan's Syndrome. Of these patients, 50% had significant permanent (or potentially so) ametropic functional amblyopia (visual acuity 20/50 to 20/200) in spite of good conservative management. This was especially true (100%) if the amount of lens dislocation was such that the lens edge was approaching the center of the pupil (vision still primarily phakic). The worst amblyopia was noted when the lens was still covering the visual axis and the lens edge was 1.3 mm from the center of the pupil (range of 0.3 to 2.3 mm). With regard to the most serious complication of ectopia lentis and its treatment, retinal detachment, when it occurred in our patients it was more strongly related to axial high myopia than surgery, per se. Since the axial high myopia which characteristically develops in ectopia lentis is probably the result of the amblyopia or the amblyopiagenic optics of ectopia lentis, lentectomy may be indicated early in this condition, before the axial high myopia develops, to prevent both axial high myopia and the attendant risks of retinal detachment as well as functional amblyopia. If the refractive error cannot be corrected well and the resultant ametropic amblyopia does not respond to conservative management, early surgery should be considered. If the lens is subluxated so that the edge of the lens approaches to within 0.3 to 2.3 mm of the center of the pupil (with best correctable vision still phakic), this is highly probable.

Adolescent↗

PubMedDate not supplied

Natural history of acquired retinal oxalosis in a child.

We report the natural history of acquired retinal oxalosis in a child with chronic renal failure. The clinical manifestations were characterized by a transient crystalline retinopathy, but stable, diffuse, flecked retina-like changes and focal hypertropic retinal pigment epithelial lesions. The pathophysiology and previous reports of retinal oxalosis are reviewed.

Calcium Oxalate↗

PubMedDate not supplied

Orbital pseudotumor in a child with juvenile rheumatoid arthritis.

We report a child with persistent fevers, arthritis, and parvoviral infection who subsequently developed unilateral orbital pseudotumor, lytic bone lesions, bilateral anterior uveitis, band keratopathy, and migratory polyarthritis. Our working diagnosis was systemic-onset juvenile rheumatoid arthritis, although pseudotumor of the orbit and lytic bone lesions are not found in this disease.

Arthritis, Juvenile↗