Broniarczyk-Loba A

Clinical application of 3D pre-bent titanium implants for orbital floor fractures

INTRODUCTION Orbital structures are affected in approximately 40% of all cases of craniofacial trauma. Changes in the bony orbital dimensions can alter the function of intraorbital contents and lead to serious complications. The unique anatomy of the orbit and the resulting surgical approaches make the process of fitting and aligning implants difficult, time consuming and operator dependent. It is now possible to make relatively inexpensive anatomical models on the basis of computed tomography images, using rapid prototyping. Such models can be used as templates to form titanium mesh implants, which are then used in the reconstruction of orbital floor defects. MATERIAL AND METHODS Six patients with facial trauma were included in this study. First, 3D virtual models and then physical models were created. These were used as templates to shape the titanium mesh and then intraoperatively as guides to aid correct implant placement in the orbit. RESULTS Significant improvement resulted in three cases and total recovery in three cases. CONCLUSION It is financially viable to build anatomical models, on the basis of CT studies, that can be used in the repair of orbital floor fractures.

Treatment with individual orbital wall implants in humans – 1-Year ophthalmologic evaluation

BACKGROUND In 2009 a method of creating individual, patient specific orbital wall implants using rapid prototyping (RP) was shown in a preliminary human study. That study showed that it is financially viable to produce anatomical models and that this technology could be used in the repair of orbital floor fractures. MATERIALS AND METHODS In this study, 24 consecutive subjects who had sustained orbital fractures (14 males, 6 females) without any coexisting central nervous system or globe injury were assessed post-operatively. The first series of 12 patients, recruited during the period 2005-2006, were treated with classical method (CM) of forming titanium mesh by manual manipulation, based on individual subjective assessment of the extent and shape of damaged orbital walls. The following 12 cases, recruited between 2007 and 2008, were treated with patient specific titanium mesh implants designed with an RP method. Early (2 weeks) and late (12 months) follow-up was performed. Patients were evaluated by binocular single vision (BSV) test and an assessment of eye globe motility. RESULTS The superiority of the RP treatment method over CM was shown on the basis of early results when BSV loss area and reduction of vertical visual disparity (VVD) in upgaze were considered. Better outcomes for the RP group were confirmed in the late follow-up results which showed a reduction of BSV loss area, correction of primary globe position and a very significant improvement in upgaze. CONCLUSIONS One-year post-operatively, functional assessment of pre-bent individual implants of the orbital wall has shown the technique to be a predictable reconstruction method. Nevertheless longer follow-up and an increase in the number of cases treated are required for the full evaluation of the technique.

Management of persistent diplopia after surgical repair of orbital fractures

PURPOSE To present the results of management of patients with persistent diplopia after orbital reconstructive surgery with respect to the type of ocular motility impairment pattern. METHODS All patients referred during a 2-year period because of persistent diplopia after surgical repair of orbital fracture were categorized according to the degree and pattern of ocular motility impairment on the basis of orthoptic examination 3-4 weeks postoperatively. Patients were followed for a mean period of 10.5 months (range, 6-12 months), during which adequate treatment was implemented. RESULTS A total of 52 patients were included in the study (45 males; mean age, 41.8 ± 16.6 years). Most could be divided into 1 of 4 groups according to the type of ocular motility impairment. The follow-up orthoptic examination revealed resolution of diplopia in 9 patients (15%) and persistent but unbothersome diplopia in 26 (43.4%). Significant diplopia was treated conservatively in 3 patients (5%) and with strabismus surgery in 14 (23.3%) cases. CONCLUSIONS The results of this study indicate that in most cases of persistent diplopia after reconstructive surgery for orbital fractures, symptoms resolve over time without treatment; nevertheless, strabismus surgery is unavoidable in some cases.

The use of modern imaging techniques in the diagnosis and treatment planning of patients with orbital floor fractures

Summary Background Ocular motility impairment associated with orbital trauma may have several causes and manifest with various clinical symptoms. In some cases orbital reconstructive surgery can be very challenging and the results are often unsatisfactory. The use of modern imaging techniques aids proper diagnosis and surgical planning. Case Report The authors present the case of a 29-year-old male who sustained trauma to the left orbit. Orthoptic examination revealed limited supra- and infraduction of the left eye. The patient reported diplopia in upgaze and downgaze with primary position spared. Dynamic magnetic resonance imaging (dMRI) was performed, which revealed restriction of the left inferior rectus muscle in its central section. A patient-specific anatomical model was prepared on the basis of 3-dimensional computed tomography (CT) study of the intact orbit, which was used to prepare a custom pre-bent titanium mesh implant. The patient underwent reconstructive surgery of the orbital floor. Conclusions Modern imaging techniques such as dMRI and 3-dimensional CT reconstruction allow us to better understand the pathophysiology of orbital floor fractures and to precisely plan surgical treatment.

The efficacy of vertical rectus transposition and its modalities in patients with abducens nerve palsy.

Purpose Patients with VIth nerve palsy that does not resolve within 6 months should undergo surgery. The most common procedure used in such cases is transposition of a whole or a part of a vertical rectus muscle combined or not with a resection of the lateral rectus muscle. Commonly, a simultaneous recession of medial rectus muscle with or without prior injection of botulinum toxin is performed. The aim of our study was to evaluate the results of vertical rectus transposition performed in patients with abducens nerve palsy. Methods Nine cases of abducens nerve palsy ware retrospectively analyzed. All patients underwent full ophthalmic and orthoptic examination before and after surgery. All patients underwent vertical rectus muscle transposition to the lateral rectus insertion in the affected eye. Additional procedures included Jensen procedure, botulinum toxin injection, resection of the lateral rectus, recession of the medial rectus on the same side with or without adjustable sutures, and Foster modification of lateral rectus posterior fixation. Results In all cases, we found a varying degree of postoperative improvement. There was a significant reduction in the strabismus angle for distance and near, increase in abduction of the affected eye, and broadening of the field of binocular single vision. Conclusions The vertical rectus muscle transposition technique is a safe and successful method of treatment in abducens nerve palsy. Its use together with additional procedures and modifications allows one to achieve orthophoria, improvement of abduction, and larger field of binocular single vision.

The influence of a prolonged interoperative period on binocular vision after bilateral cataract extractions.

Purpose To evaluate the influence of the extent of the interoperative period on binocular vision function in patients after consecutive bilateral cataract extractions and intraocular lens implantation. Methods The study included patients operated due to bilateral cataract. Presence of asthenopic symptoms, distance and near squint angle, fusional amplitudes, stereopsis, and convergence were evaluated. Preoperative, interoperative, and postoperative differences in best-corrected visual acuity between eyes were also noted. Multivariate analysis was conducted in order to establish the relation between the interoperative period and binocular status. Results The study included 104 patients (74 female, 30 male, mean age 69.9 years, range 32-88). Mean interoperative period was 20.3 ± 12.9 months, range 1.5-47.7. Prolongation of the interoperative interval had a significant negative impact on stereopsis measured by TNO (R2 = 0.215, p = 0.001) and Randot (R2 = 0.179, p = 0.001) stereotests, as well as for near point of convergence (R2 = 0.09, p = 0.002). It was also related, but not independently, to reduction in fusional amplitudes, mainly for distance (R2 = 0.18, p = 0.001 for divergence and R2 = 0.12, p = 0.001 for convergence). Asthenopic symptoms were reported by 17 (16.3%) patients. The incidence of exophoria was significantly (p = 0.002) higher in patients with an interoperative interval longer than 24 months. Conclusions The length of the interoperative period influences the status of binocular vision in patients after bilateral cataract extraction. It is also connected with an increased number of patients with asthenopic symptoms and exophoria.

Morphometric parameters of extraocular rectus muscles evaluated by dynamic-multipositional magnetic resonance.

Purpose To establish normal values of morphologic parameters of extraocular rectus muscles visualized in different gaze positions by means of an accessible method of dynamic-multipositional magnetic resonance imaging (dmMRI). Methods Twenty eyes of 10 healthy, orthotropic subjects were examined. A 1.5T scanner (Avanto) with standard head coil was used. The protocol of dmMRI included 6 gaze positions in 10° intervals in which 13-second, orbital, T2 sequences were performed in quasi-coronal plane. The measurements of extraocular rectus muscles shape, sectional area, and volume were obtained with use of ImageJ 1.38x (NIH) software. Results Relative change in cross-sectional area between position of rest and gaze of action of each muscle appears to be significant just in the medial and posterior parts of their belly. The maximal cross-section area increases significantly when the muscle contracts (21% to 32% depending on the muscle). The superior rectus must be assessed along with levator palpebrae as the distinction between their bellies is difficult. Relative change in partial muscle volume on contraction ranged from 12.3% to 21.6% depending on the muscle. Muscle contraction results in more circular shape of its belly while relaxation is more of an ellipse. Conclusions Dynamic-multipositional MRI performed in the proposed manner is an accessible and repeatable method for visualization of extraocular rectus muscles. Assessment of morphometric parameters such as muscle shape, maximal cross-section area, and partial muscle volume is easy with digital imaging software.