Piotr Loba

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.

Comparison of early corneal endothelial cell loss after coaxial phacoemulsification through 1.8 mm microincision and bimanual phacoemulsification through 1.7 mm microincision

PURPOSE: To compare corneal endothelial cell loss after coaxial 1.8 mm microincision cataract surgery (MICS) and bimanual 1.7 mm MICS. SETTING: Department of Ophthalmology, Medical University of Lodz, Lodz, Poland. METHODS: The study comprised a nonrandomized prospective consecutive series of 51 eyes of 51 patients who had coaxial MICS with implantation of an MI60 foldable intraocular lens (IOL) using a 1.8 mm temporal clear corneal microincision. Fifty eyes of 50 patients who had uneventful bimanual MICS through a 1.7 mm temporal clear corneal incision for a sleeveless phaco tip and a side port for an irrigating chopper with a foldable Acri.Smart 48S foldable IOL implantation served as a reference group. Corneal endothelial cell density, intraoperative phaco power, effective phaco time, and preoperative and postoperative visual acuities were evaluated. The measurements were performed in a semiautomated masked manner. Statistical analysis was done using nonparametric tests (Wilcoxon signed rank test and Mann‐Whitney U test). RESULTS: The patients were examined preoperatively and 2 weeks to 1 month postoperatively. The mean follow‐up was 22.58 days ± 5.08 (SD). Postoperatively, the mean corrected distance visual acuity (CDVA)was 0.95 ± 13 in both groups. There was a significant decrease in endothelial cell density in both groups, 9.46% in Group 1 and 9.27% in Group 2. The between‐group difference was not statistically significant (P>.05, Mann‐Whitney U test). CONCLUSIONS: The visual results were excellent in both groups. Both MICS techniques enabled preservation of corneal endothelial cells equally well and were similar in terms of minor surgical trauma and the influence of surgery on corneal endothelial cell density. Our results support the use of both MICS techniques for cataract surgery.

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.

Results of Coaxial Phacoemulsification Through a 1.8-mm Microincision in Hard Cataracts

BACKGROUND AND OBJECTIVE To assess the results of coaxial phacoemulsification through 1.8-mm coaxial microincision cataract surgery (C-MICS) phacoemulsification with foldable intraocular lens implantation in eyes with hard cataracts in comparison to eyes with soft cataracts. PATIENTS AND METHODS Group 1 consisted of 40 eyes of 40 patients with hard cataracts (grade ≥ 4, Lens Opacities Classification System III scale) and group 2 consisted of 45 eyes of 45 patients with non-mature cataracts (grade ≤ 2, Lens Opacities Classification System III scale). All surgeries were performed by two experienced surgeons under topical and intracameral anesthesia. Examinations were performed preoperatively and 1 month after the surgery. Examined parameters included distance-corrected visual acuity (DCVA), autorefractometry, keratometry, tonometry, endothelial cell counts, and biomicroscopy of the anterior and posterior segment. Surgically induced astigmatism was calculated with vector analysis. RESULTS Mean DCVA was 0.16 ± 0.16 preoperatively and 0.92 ± 0.21 postoperatively in group 1 (P < .05) and 0.62 ± 0.18 preoperatively and 0.97 ± 0.08 postoperatively in group 2 (P < .05). Mean surgically induced astigmatism was 0.48 ± 0.44 in group 1 and 0.53 ± 0.38 in group 2 (P > .05). Mean endothelial cell loss was 11.37% ± 12.87% in group 1 and 2.87% ± 9.66% in group 2 (P < .05). CONCLUSION Although density of cataract has an unfavorable influence on early postoperative corneal endothelial cell loss, it did not significantly influence final DCVA and surgically induced astigmatism. C-MICS is a safe and effective method of treatment of cataracts, including cataracts with hard nuclei, and usually leads to good functional outcomes.

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.

Surgical management of upgaze diplopia in patients after posttraumatic orbital floor reconstruction

OBJECTIVE The most common complication of otherwise successful reconstructive surgery of a fractured orbital floor is persistent diplopia. For patients with troublesome double vision in upgaze, a reasonable solution is offered by strabismus surgery. The aim of our study is to examine the results of extraocular muscle surgery in cases of diplopia that persisted in upgaze after posttraumatic orbital floor reconstruction. MATERIAL AND METHODS In this study we present a retrospective series of 24 patients with troublesome vertical diplopia in upgaze. In all cases, the surgery consisted of a posterior fixation suture placement on the contralateral superior rectus muscle with or without its recession. Full orthoptic examination was conducted before and 3 months after the surgery. RESULTS Postoperatively 19 patients (79%) were diplopia free and 6 (21%) had vertical diplopia in extreme upgaze. The field of binocular single vision improved threefold. None of the patients reported diplopia in the primary position or in any position other than upgaze. CONCLUSION Vertical incomitant strabismus and diplopia in upgaze persisting after orbital reconstructive surgery may be corrected surgically. Contralateral posterior fixation of the superior rectus muscle, with or without its recession, appears to be an effective procedure for use in these patients.

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.

Signal intensity and T2 time of extraocular muscles in assessment of their physiological status in MR imaging in healthy subjects.

Summary Background: Lack of standardised orbital MR protocols leads to a situation, when each institution/centre may arbitrarily choose sequence parameters. Therefore, the results obtained and published by the authors may not be compared freely, and what is most important may not be considered fully reliable. Signal intensity (IS) and T2 time (T2) are important parameters in estimation of inflammatory processes of extraocular muscles in the clinical practice. The aim of this study was to determine the reference values (i.e. cut-off values) for absolute signal intensity and T2 relaxation time in healthy subjects, their relativised values to white matter (WM) and temporal muscles (TM) and to evaluate the correlation between those parameters. Material/Methods: The orbital examination was performed in healthy volunteers according to the protocol prepared in the Radiology-Imaging Diagnostic Department of the Medical University of Lodz for patients with suspected/diagnosed thyroid orbitopathy. Using two of the standard sequences IS and T2 time were calculated for the muscles and two relativisation tissues in realtion to WM and TM. Subsequently cut-off values for healthy volunteers were calculated. Results: The differences between muscles for IS, IS MAX, IS/TM, IS/WM, IS MAX/TM, IS MAX/WM and T2 MAX/WM were not statistically significant. Therefore one cut-off value of these parameters for all the rectus muscles was calculated. T2-relaxation time and T2 relativised to white matter had to be calculated separately for each muscle. Conclusions: No statistical correlation was found between IS and T2-time for extraocular muscles in healthy volunteers. We calculated the reference ranges (cut-off values) for absolute IS and T2-time values and relativised parameters. In the clinical practice the objectification of IS and T2-time values should be done to WM, than to IS or T2 of the temporal muscle. The T2 MAX/WM seems to have the highest clinical utility for the assessment of the pathophysiological status of extraocular muscles.