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At least 937 records · Page 52Linked to original sources
PubMed2005

Potent retinal arteriolar traction as a possible cause of myopic foveoschisis.

PURPOSE: To report retinal microfold formation after vitrectomy for myopic foveoschisis (MF). DESIGN: Prospective observational study. METHODS: We observed 21 eyes of 17 patients who had undergone vitrectomy for MF with optical coherence tomography (OCT) in this institutional study. We also evaluated the three-dimensional retinal architecture using the OCT-ophthalmoscope in selected cases. Vitrectomy included core vitrectomy, vitreous cortex removal, internal limiting membrane (ILM) peeling with indocyanine green, and gas tamponade. RESULTS: Horizontal linear folds were commonly observed postoperatively. The folds, which were 1,000 to 2,000 microm superior, inferior, or both superior and inferior to the fovea, were detected only by OCT and not by conventional slit-lamp-based biomicroscopy. The microfolds were found in only five eyes (24%) 1 month postoperatively. The incidence increased over time, however, and a microfold was detected in nine eyes (43%) 3 months after surgery and in 13 (62%) 6 months after surgery. OCT-ophthalmoscope examination confirmed the location of the microfold coincided exactly with that of retinal arteriole. The presence of microfolds was not significantly related to the postoperative visual acuity. CONCLUSIONS: Retinal microfolds are common in eyes with MF after vitrectomy with ILM peeling, and they seem to be generated as the result of insufficient flexibility of the sclerotic retinal arteriole during axial length elongation in highly myopic eyes. This finding suggests that the inward tractional force on the retina along the arteriole may be closely related to the pathogenesis of vitreoretinal diseases specific to high myopia, including MF or paravascular microhole formation.

Aged↗
PubMed2005

Orthodontic treatment of a traumatically intruded tooth with ankylosis by traction after surgical luxation.

This report presents the treatment of a patient with anterior crossbite and displacement of ankylosed maxillary and mandibular right lateral incisors. The maxillary lateral incisor, which was traumatically intruded, was successfully treated with 2 surgical luxations followed by orthodontic traction. The mandibular lateral incisor, which was avulsed and replanted, experienced replacement root resorption during orthodontic treatment and was ultimately extracted. Two years after active orthodontic treatment, the occlusal results were considered satisfactory.

Cephalometry↗
PubMed2004

Anterior shoulder dislocations: beyond traction-countertraction.

The shoulder is the most commonly dislocated large joint presenting to American Emergency Departments (ED). Anterior dislocations account for the great majority of these dislocations. Most anterior shoulder dislocations can be reduced in the ED using a variety of reduction techniques. The traction-countertraction technique is quite familiar to most Emergency Physicians, however, many other effective methods of reduction have been described. No method has proven 100% successful, and occasionally multiple attempts using different techniques are required to effect reduction. This article reviews some of the other techniques used to reduce anterior shoulder dislocations, variations reported on these techniques, and their success rates, advantages, and disadvantages.

Emergency Medical Services↗
PubMed1997

Epiretinal membrane and traction retinal detachment complicating laser-induced chorioretinal venous anastomosis.

PURPOSE: To report a patient with a sight-threatening complication of laser-induced chorioretinal venous anastomosis for treatment of central retinal vein occlusion. METHOD: A 69-year-old woman with a nonischemic central retinal vein occlusion underwent focal argon laser photocoagulation treatment to create a chorioretinal venous anastomosis. RESULTS: Massive preretinal fibrosis and traction retinal detachment developed over the area of argon laser photocoagulation, which required vitreous surgery. CONCLUSION: Laser-induced chorioretinal venous anastomosis to treat central retinal vein occlusion can be associated with severe complications, underscoring the need for additional study of this new treatment modality.

Aged↗
PubMed1995

Tractional elevation of Henle's fiber layer in idiopathic macular holes.

PURPOSE: We sought to clarify the morphologic features of macular hole development. METHODS: Using scanning laser ophthalmoscopy, we examined 47 eyes with macular holes before and after vitrectomy. Cases included three eyes with stage 1B disease (foveal detachment), 14 with stage 2 (break at the fovea), 21 with stage 3 (full-thickness macular hole), and nine with stage 4 (detached operculum), according to Gass's classification. Ten eyes with central serous chorioretinopathy served as controls. RESULTS: Radiating striae of Henle's fibers were seen around the elevated rim of the macular cyst or hole when the intraretinal structures were illuminated by helium-neon laser. Granularity was observed on the macular hole floor. A granular reflex corresponding to the macular break or hole, but no radiating striae were seen by argon blue laser. In 40 eyes in which macular holes were successfully closed by vitrectomy, radiating striae of Henle's fiber layer disappeared, and the normal foveal depression was restored. The ten eyes with central serous chorioretinopathy had a normal foveolar depression and no detectable radiating striae of Henle's fiber layer, despite full-thickness retinal detachment in the macular area. CONCLUSIONS: Tractional elevation of Henle's fiber layer with intraretinal foveolar cyst formation is the initial feature of macular hole development. A macular hole is formed when the anterior cyst wall containing Henle's fiber layer is operculated. Remnants of the photoreceptor cell layer remain on the hole floor in the early stage of macular hole development and subsequently degenerate.

Adult↗
PubMed1993

Traction retinal detachment. XLIX Edward Jackson Memorial Lecture.

This review had two main objectives. The first goal was to attempt to define a final common pathway for traction retinal detachment. To illustrate this, I considered the following three common clinical entities: penetrating ocular trauma, proliferative vitreoretinopathy, and proliferative diabetic retinopathy. My second goal was to emphasize the role of research in developing a rational approach to treatment. To illustrate the second goal, I reviewed the contributions from three realms of research--laboratory, animal, and clinical research--examining their interactions and considering their roles in our current understanding and management of these clinical entities.

Diabetic Retinopathy↗
PubMed1981

Tractional venous loops in diabetic retinopathy.

A venous loop developed in a patient with proliferative diabetic retinopathy. Fluorescein angiography showed staining of the vessel wall and nonperfusion of the surrounding capillary bed. Light microscopy and scanning and transmission electron microscopy showed the loop to consist of a telangiectatic retinal vein that had passed through a discontinuity in the internal limiting membrane. The thin-walled vessel loop was lined by an attenuated endothelium and occasional pericytes. The vitreous was detached posteriorly except at the venous loop and a few other points at which there was tenting of the internal limiting membrane. These findings suggested that vitreous traction plays a role in the pathogenesis of these venous loops.

Aged↗
PubMed1977

Removal of infected epicardial electrodes by traction.

Five patients who had infected cardiac pacemakers with epicardial electrodes have been managed by exteriorization of the pulse generator and placement of an endocardial unit. In each case the remaining electrode leads where detached from the myocardium and removed by simple traction, avoiding a surgical procedure. In 4 patients, sets of cables had been sutured to the myocardium through an anterior thoracotomy, in some instances using Teflon pledgets as buttresses. In one of these procedures a pericostal suture had been used to secure the leads from the thoracic cavity against the ribs. The remaining patient had received a subxiphoid pacemaker also implanted with sutures. This is a consecutive series, and we have had no failures so far. All pulse generator units were bipolar and located beneath either the pectoral or the rectus muscle. All of them were functioning properly when infection was diagnosed. This procedure constitutes an alternative method of management when more conservative techniques, such as closed irrigation and debridement, cannot be utilized.

Aged↗
PubMed2001

Lens-sparing vitreous surgery for tractional stage 4A retinopathy of prematurity retinal detachments.

PURPOSE: To assess the efficacy of lens-sparing vitrectomy in tractional 4A retinopathy of prematurity (ROP) retinal detachments in reducing progression to stage 4B or 5 ROP. DESIGN: Retrospective, noncomparative consecutive case series. PARTICIPANTS: Forty eyes (31 patients) with stage 4A ROP at 38 to 42 weeks post-conceptional age. INTERVENTION: Lens-sparing vitrectomy. MAIN OUTCOME MEASURES: Retinal attachment status and presence/absence of fixation behavior. RESULTS: The range of follow-up was 6 to 22 months (mean, 12 months). Ninety percent (36 of 40) of eyes showed retinal reattachment and fixation behavior at their last follow-up visit. CONCLUSIONS: These results suggest that vitreous surgery can interrupt progression of ROP from stage 4A to stages 4B or 5.

Female↗
PubMed1980

New instrument for the quantitative determination of passive forced traction.

An instrument for the quantitative analysis of the passive forced traction test on strabismic patients under anesthesia is described. This spring dynamometer measures the grams of force required to displace the eye from its rest position into the various fields of rotation of the globe. Measurements on a control population are compared with both non-restrictive and restrictive strabismic patients. Characteristics of various types of restrictions encountered are mentioned as an aid to more precise diagnosis of specific strabismic problems.

Adolescent↗
PubMed1981

Pars plana vitrectomy for diabetic traction retinal detachment.

One hundred twenty-five consecutive cases of traction macular detachment secondary to diabetic retinopathy are analyzed. Visual results show 72% to have improvement. Long-term follow-up (average 39 months) of the initial 75 cases revealed that 62% of the initially improved cases remained improved. Neovascular glaucoma rate continues to be higher in aphakic eyes as compared to phakic eyes.

Adult↗
PubMed1981

Exaggerated traction test for the oblique muscles.

Retroplacement and torsional manipulation of the globe during forced duction testing provide an exaggerated traction test of the oblique muscles, allowing graded evaluation of superior oblique and inferior oblique tightness. On a scale from 0 to 4 +, normal superior oblique tightness averages 1.5+, and normal inferior oblique tightness averages about 1+. The degree of superior oblique or inferior oblique tightness correlates well with clinical overaction of these muscles, allowing better distinction between oblique overaction and dissociated vertical deviation. Also, the effect of partial superior oblique tenotomy can be monitored, and a complete tenotomy can be confirmed with certainty.

Humans↗
PubMed1991

Vitreoretinal traction and perimacular retinal folds in the eyes of deliberately traumatized children.

The pathophysiology of perimacular folds in eyes of deliberately traumatized children is disputed. The authors reviewed the clinical and forensic records and systemic and ocular findings at autopsy of three children with perimacular retinal folds who died after being violently shaken. Two of the children suffered direct head trauma in addition to being shaken; one patient was violently shaken without any physical or forensic evidence of direct head trauma. No direct ocular trauma was detected. In each case, the vitreous had partially separated from the retina but remained attached to the internal limiting membrane at the apices of the folds and the vitreous base, implicating traction in the pathogenesis of these folds. Although some intraocular findings in deliberately traumatized children may be explained by direct head injury, the possibility of both direct head trauma and shaking must be considered. Perimacular folds may develop without direct ocular or head trauma and may constitute evidence supporting violent shaking.

Battered Child Syndrome↗
PubMed1996

Recognition of vitreoschisis in proliferative diabetic retinopathy. A useful landmark in vitrectomy for diabetic traction retinal detachment.

INTRODUCTION: In the late stages of proliferative diabetic retinopathy (PDR) the vascularized posterior cortical gel (PCG) contracts leading to a partial posterior hyaloidal separation, hemorrhage, and traction retinal detachment (TRD). "Additional epiretinal membranes" have been described previously. These are thin, usually transparent epiretinal membranes which extend anteriorly from the point of attachment of the elevated posterior cortical gel to the edge of the TRD. The origin and frequency of the occurrence as well as the clinical significance of such additional epiretinal membranes are the subjects of controversy. PURPOSE: To quantitate the authors' clinical impression that additional epiretinal membranes are common in advanced PDR, to characterize them immunohistochemically, and to demonstrate the rationale for the authors' surgical approach. METHODS: Intraoperative observations for all patients undergoing diabetic vitrectomy and delamination over the last 2 years were reviewed retrospectively. The presence of additional epiretinal membrane was searched for in the initial stages of vitrectomy. When identified, their apparent continuity with the elevated portion of the PCG was confirmed. Surgical specimens were obtained from nine patients for immunohistochemical study. RESULTS: Additional epiretinal membranes were observes in 145 (81%) of 179 consecutive eyes with PDR that underwent surgery for macular TRD. Immunohistochemical staining with type II collagen antibody was positive in all specimens, suggesting that these membranes were of vitreous origin. CONCLUSIONS: It is likely that the additional epiretinal membranes represent the posterior leaf of a split PCG, the anterior leaf being the elevated portion of the PCG. The two leaves remain fused in the main, fibrovascular portion of the epiretinal membrane. These findings help explain the clinical experience that once the posterior leaf of the PCG is identified and elevated, it provides an accurate point of entry into the surgical plane facilitating delamination of the fused (vascularized) portion of the PCG from the detached retina.

Aged↗
PubMed1992

Papillary muscle traction in mitral valve prolapse: quantitation by two-dimensional echocardiography.

Previous angiographic observations in patients with mitral valve prolapse have suggested that superior leaflet displacement results in abnormal superior tension on the papillary muscle tips that causes their superior traction or displacement. It has further been postulated that such tension can potentially affect the mechanical and electrophysiologic function of the left ventricle. The purpose of this study was to confirm and quantitate this phenomenon noninvasively by using two-dimensional echocardiography to determine whether superior displacement of the papillary muscle tips occurs and its relation to the degree of mitral leaflet displacement. Directed echocardiographic examination of the papillary muscles and mitral anulus was carried out in a series of patients with classic mitral valve prolapse and results were compared with those in a group of normal control subjects. Distance from the anulus to the papillary muscle tip was measured both in early and at peak ventricular systole. In normal subjects, this distance did not change significantly through systole, whereas in the patient group it decreased, corresponding to a superior displacement of the papillary muscle tips toward the anulus in systole (8.5 +/- 2.6 vs. 0.8 +/- 0.7 mm; p less than 0.0001). This superior papillary muscle motion paralleled the superior displacement of the leaflets in individual patients (y = 1.0x + 0.8; r = 0.93) and followed a similar time course.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Changes in the masticatory jaw movement following orthodontic traction of an impacted and transposed upper canine and occlusal adjustment.

In a 10-year-old female with an impacted and completely transposed upper left canine, posterior temporal muscle activity and jaw movement during mastication were examined before and after orthodontic traction of the canine, alignment of teeth, and occlusal adjustment of the canine. After the orthodontic treatment, but before the occlusal adjustment, esthetic improvement in the static occlusion was achieved. The posterior temporal muscle on the non-chewing side exhibited earlier bursts in the electromyography. Jaw movement trajectory of the jaw-closing phase at a level close to the maximum intercuspation position was more to the medial side on the frontal view, and the jaw-closing velocity in the lateral direction was slower during left-sided chewing. Following occlusal adjustment of the transposed canine, however, the muscle activity and jaw movement patterns were improved to normal patterns. We suggest that it might be advisable to perform occlusal adjustment at an early stage during the retention period in such cases.

Journal Article↗
PubMed1999

Stability of implants as anchorage for orthopedic traction.

The aim of this animal study was to investigate the stability of osseointegrated fixtures when used as anchorage for orthopedic traction with extreme force magnitude. Three Brånemark fixtures were placed in the left zygomatic arch and three in the right of five adult dogs. An orthopedic nonaxial force of 5 N was applied using an intraoral coil system. The initial displacement immediately after force application was measured by means of speckle interferometry. After 2 months of continuous loading, bone adaptation and mineralization around all implants were analyzed. All the loaded implants were immobile. Significant marginal bone loss at the abutment-fixture interface (<1 mm) was observed around each loaded fixture implant. Bone remodeling was significantly more pronounced at the tension side of the implants, irrespective of fixture length. Radiographical and histological analyses showed bone with normal trabecular pattern around the implants.

Adaptation, Physiological↗
PubMed2000

[Pars-plana vitrectomy in diabetic traction retinal detachments with holes].

PURPOSE: To evaluate results and prognostic factors of pars-plana vitrectomy (ppv) using membrane peeling and C2F6-gas for diabetic traction retinal detachments with a hole. METHODS: We retrospectively reviewed the healing course of 84 eyes, which were treated in this way consecutively (follow-up 6-32 month). C2F6 was always used in case of a retinal hole at the posterior pole or in the upper part of the eye. The influence of HBA1c, type of diabetes, preoperative visual acuity, preoperative laser-coagulation and macular status over treatment results and rate of complications were studied using multivariate logistic regression analysis. RESULTS: Preoperatively 56% of the eyes showed premacular vitreous hemorrhage and 69% macular detachment. Using on an average 1.3 treatments in 73% retina was completely reattached and in 85% visual acuity remained unchanged or improved. The most important prognostic factors were HBA1c < 9.3, type II diabetes and bad vision preoperatively. Postoperative complications such as rubeosis, secondary glaucoma and repeated vitreous hemorrhages were more frequent in case of type I diabetes, HBA1c > or = 9.3 and insufficient laser treatment. CONCLUSION: Best corrected blood sugar levels preoperatively and sufficient laser treatment seem to be very important to decrease the risk for rubeosis and repeated vitreous hemorrhages especially for patients with type I diabetes.

Adult↗