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Journal of Binocular Vision and Ocular... 2022Fusional potential in patients experiencing binocular torsional diplopia may be challenging for the clinician to assess, particularly when accompanied by vertical and...
INTRODUCTION
Fusional potential in patients experiencing binocular torsional diplopia may be challenging for the clinician to assess, particularly when accompanied by vertical and horizontal diplopia.
OBJECTIVE
To demonstrate a clinical test that may help predict if binocular fusion can be achieved once cyclotorsion is alleviated.
DESIGN
Video recording demonstrating how to perform the white disk test and retrospective chart review of patients tested with the white disk test.
RESULTS
Twelve patients with binocular torsional diplopia were included. All subjects had excyclotorsion, 11 (91.7%) had combined vertical and horizontal strabismus and 1 patient (8.3%) had vertical strabismus. Eleven patients (91.7%) were able to achieve single binocular vision with the white disk test and 1 patient (8.3%) demonstrated brittle fusion. The white disk test successfully predicted postoperative fusion in 10 of 11 patients (90.9%). Eight patients (66.7%) demonstrated improved stereopsis after surgery.
CONCLUSION
The white disk test was found to be very useful in predicting fusional potential in patients that experience binocular torsional diplopia.
Topics: Humans; Diplopia; Retrospective Studies; Strabismus; Vision, Binocular; Depth Perception
PubMed: 35994693
DOI: No ID Found -
BioNanoScience 2022Interest is growing in nanopores as real-time, low-cost, label-free virus size sensors. To optimize their performance, we evaluate how external electric field and ion...
Interest is growing in nanopores as real-time, low-cost, label-free virus size sensors. To optimize their performance, we evaluate how external electric field and ion concentrations and pore wall charges influence currents and object (disk) radius-current relationship using simulations. The physics was described using the Poisson-Nernst-Planck and Navier-Stokes equations. In a charged cylindrical nanopore with a charged disk, elevated external electric field produces higher (and polarity independent) ion concentrations and greater ion current (largely migratory). Elevated external ion concentrations also lead to higher concentrations (mainly away from the pore wall), greater axial electric field especially in the disk-pore wall space, and finally larger current. At low concentrations, current is disk radius independent. The current rises as concentrations increase. Interestingly, the rise is greater for larger disks (except when the pore is blocked mechanically). Smaller cross-sectional area for current flow or volume exclusion of electrolyte by object thus cannot be universally accepted as explanations of current blockage. Ion current rises when pore wall charge density increases, but its direction is independent of charge sign. Current-disk radius relationship is also independent of pore wall charge sign. If the pore wall and disk charges have the same sign, larger current with bigger disk is due to higher counter-ion accumulation in the object-pore wall space. However, if their signs are opposite, it is largely due to elevated axial electric field in the object-pore wall space. Finally in uncharged nanopores, current diminishes when disk radius increases making them better sensors of virus size.
PubMed: 35607652
DOI: 10.1007/s12668-022-00990-2 -
Indian Journal of Ophthalmology Dec 2022The current study was aimed at assessment of optic disk by disk damage likelihood scale (DDLS) staging using slit-lamp biomicroscopy and optical coherence tomography... (Observational Study)
Observational Study
PURPOSE
The current study was aimed at assessment of optic disk by disk damage likelihood scale (DDLS) staging using slit-lamp biomicroscopy and optical coherence tomography (OCT) in diagnosing primary open-angle glaucoma (POAG) patients.
METHODS
This was a cross-sectional observational study of 106 POAG patients, which was conducted from April 2017 to April 2018. All patients underwent slit-lamp fundoscopy with a +78 D lens and high-definition (HD)-OCT, and the vertical cup disk ratios (VCDRs) were recorded. Disk size and neuroretinal rim assessment were done, and the disk was then staged using the recent version, which stages the optic nerve head (ONH) from 1 to 10 as read from the DDLS nomogram table. DDLS scores >5 indicate glaucomatous damage. Pearson coefficient was used to correlate the DDLS staging by slit-lamp biomicroscopy with best-corrected visual acuity (BCVA), intraocular pressure (IOP), disk size, and VCDR and VCDR, mean deviation, and DDLS staging by HD-OCT.
RESULTS
The mean age of the patients was 59.54 ± 6.61 years. The male: female ratio was 2:1. The mean IOP was 16.04 ± 1.97 mmHg, and BCVA was 0.72 ± 0.13 LogMAR units. The mean VCDR on 78 D slit-lamp biomicroscopy was 0.76 ± 0.09 (standard deviation [SD]) (range 0.1-0.77), whereas on HD-OCT, the mean VCDR was 0.81 ± 0.09 (SD) (range 0.07-0.81). The mean deviation on visual field testing in decibels was -14.43 ± 3.31 (SD). The correlation coefficient between DDLS staging by slit-lamp biomicroscopy and DDLS staging by HD-OCT parameters was r = 0.96.
CONCLUSION
There is a positive correlation between the DDLS system of optic disk evaluation on slit-lamp biomicroscopy and most of the HD-OCT evaluation parameters.
Topics: Humans; Female; Male; Middle Aged; Aged; Optic Disk; Tomography, Optical Coherence; Cross-Sectional Studies; Glaucoma, Open-Angle; Slit Lamp Microscopy
PubMed: 36453304
DOI: 10.4103/ijo.IJO_1113_22 -
Acta Neurochirurgica. Supplement 2023Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease....
Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease. The aim of the study was to perform a systematic literature review on long-term clinical and radiological outcomes after Bryan cervical disk arthroplasty.Material and Methodsː A systematic literature review was performed according to PRISMA guidelines via PubMed and Embase, Scopus, and the Cochrane Library database by using the following keywords: "Bryan prosthesis"; "cervical disk arthroplasty"; "outcomes"; and "long-term follow-up." Eight articles with at least 10 years of follow-up were considered for eligibility.Resultsː In total, 481 patients were enrolled in the studies. Because of the occurrence of multiple treated levels, 588 arthroplasties were performed, divided as follows: 12 C3/4 cervical disk arthroplasties (2.01%), 63 C4/5 (10.71%), 325 C5/6 (55.27%), and 188 C6/7 (31.97%). The mean preoperative cervical lordosis was 13.6 ± 9.3°, whereas the last follow-up value was 12.8 ± 8.7°. In the last follow-up, the mean segmental range of motion was 8.2 ± 3.3°.Discussion: Recent studies have suggested that cervical disk arthroplasty should be safely performed in healthy young patients with disk degeneration who may need future revision surgery. The results suggest that this procedure preserves native cervical spinal biomechanics at long-term follow-up with acceptable adjacent segments disease and periprosthetic ossifications.Conclusionsː Cervical disk arthroplasty has good long-term device survival, motility, adjacent segment degeneration, and clinical outcomes. Therefore, it represents a valid alternative for the treatment of cervical spine degenerative pathologies, especially in young patients.
Topics: Animals; Humans; Arthroplasty; Biomechanical Phenomena; Databases, Factual; Intervertebral Disc Degeneration; Intervertebral Disc Displacement
PubMed: 38153488
DOI: 10.1007/978-3-031-36084-8_49 -
Technology and Health Care : Official... 2016Artificial neural networks have found applications in various areas of medical diagnosis. The capability of neural networks to learn medical data, mining useful and...
Artificial neural networks have found applications in various areas of medical diagnosis. The capability of neural networks to learn medical data, mining useful and complex relationships that exist between attributes has earned it a major domain in decision support systems. This paper proposes a fast automatic system for the diagnosis of disk hernia and spondylolisthesis using biomechanical features and neural network. Such systems as described within this work allow the diagnosis of new cases using trained neural networks; patients are classified as either having disk hernia, spondylolisthesis, or normal. Generally, both disk hernia and spondylolisthesis present similar symptoms; hence, diagnosis is prone to inter-misclassification error. This work is significant in that the proposed systems are capable of making fast decisions on such somewhat difficult diagnoses with reasonable accuracies. Feedforward neural network and radial basis function networks are trained on data obtained from a public database. The results obtained within this research are promising and show that neural networks can find applications as efficient and effective expert systems for the diagnosis of disk hernia and spondylolisthesis.
Topics: Biomechanical Phenomena; Diagnosis, Computer-Assisted; Diagnosis, Differential; Female; Humans; Intervertebral Disc Displacement; Male; Neural Networks, Computer; Spondylolisthesis
PubMed: 26757441
DOI: 10.3233/THC-151126 -
Journal of AAPOS : the Official... Oct 2021To report a case series of children with central retinal vein occlusion (CRVO) showing a high prevalence of crowded optic disks with minimal cupping.
PURPOSE
To report a case series of children with central retinal vein occlusion (CRVO) showing a high prevalence of crowded optic disks with minimal cupping.
METHODS
We retrospectively reviewed the medical records of children diagnosed with CRVO from 2008 to 2019 at a single tertiary care pediatric hospital. Clinical records, fundus photographs, and optical coherence tomography (OCT) images were reviewed. Optic disk anatomical parameters of the unaffected fellow eyes, including OCT-measured optic disk area and vertical cup:disk ratio, were collected and analyzed.
RESULTS
Six patients with unilateral CRVO were identified. All patients were female. Age at presentation ranged between 9 and 17 years. Five patients were otherwise healthy, with negative systemic investigations (idiopathic group). The remaining patient had a known systemic risk factor of active Takayasu arteritis. Within the idiopathic group, "disk-at-risk" optic nerve configuration, defined as a cup:disk ratio of 0.2 or smaller, was identified in the fellow eye of all 5 patients. In the unaffected eyes, mean OCT-measured optic disk area was 1.67 ± 0.13 mm and mean cup:disk ratio was 0.19 ± 0.12. The patient with Takayasu arteritis had normal OCT disk area of 2.1 mm and cup:disk ratio of 0.61.
CONCLUSIONS
We observed a high prevalence of anatomical features potentially consistent with a constrictive optic disk configuration in pediatric patients with CRVO.
Topics: Adolescent; Child; Diagnostic Techniques, Ophthalmological; Female; Humans; Optic Disk; Retinal Vein Occlusion; Retrospective Studies; Tomography, Optical Coherence
PubMed: 34562620
DOI: 10.1016/j.jaapos.2021.05.009 -
World Neurosurgery Sep 2022There are currently no standard criteria for evaluating the risk of recurrent disk herniation after surgical repair. This study investigated the predictive values of 5...
OBJECTIVE
There are currently no standard criteria for evaluating the risk of recurrent disk herniation after surgical repair. This study investigated the predictive values of 5 presurgical imaging parameters: paraspinal muscle quality, annular tear size, Modic changes, modified Phirrmann disk degeneration grade, and presence of sacralization or fusion.
METHODS
Between 2015 and 2018, 188 patients (89 female, 99 male, median age 50) receiving first corrective surgery for lumbar disk herniation were enrolled. Microdiskectomy was performed in 161 of these patients, and endoscopic translaminar diskectomy approach was performed in 27 patients. Clinical status was evaluated before surgery and 4, 12, and 24 months post surgery using a visual analog scale, Oswestry Disability Index, and Short Form 36.
RESULTS
Recurrent disk herniation was observed in 21 of 188 patients. Seventeen of the recurrent disk herniations were seen in those who underwent microdiskectomy and 4 in those who underwent endoscopic translaminar diskectomy. There were significant differences in visual analog scale, Oswestry Disability Index, and Short Form 36 scores at 4, 12, and 24 months between patients with recurrence and the 167 no-recurrence patients. The median annular tear length was significantly greater in patients with recurrence than without recurrence. In addition, there were significant differences in recurrence rate according to Modic change type distribution, sacralization or fusion presence, Pfirmann disk; degeneration grade distribution, dichotomized annular tear size, dichotomized Modic change; and type and simplified 3-tier muscle degeneration classification distribution.
CONCLUSIONS
Patients with poor clinical scores and recurrence exhibited additional radiologic abnormalities before surgery, such as poor paraspinal muscle quality, longer annular tears, higher Modic change type, higher modified Phirrmann disk degeneration grade, and sacralization or fusion. This risk evaluation protocol may prove valuable for patient selection, surgical planning, and choice of postoperative recovery regimen.
Topics: Diskectomy; Female; Humans; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Lumbar Vertebrae; Magnetic Resonance Imaging; Male; Middle Aged; Treatment Outcome
PubMed: 35803567
DOI: 10.1016/j.wneu.2022.06.143 -
Veterinary Surgery : VS Jan 2022To evaluate the intervertebral disk, vertebral endplates, and spinal cord for perioperative changes secondary to percutaneous laser disk ablation (PLDA) and correlate...
OBJECTIVE
To evaluate the intervertebral disk, vertebral endplates, and spinal cord for perioperative changes secondary to percutaneous laser disk ablation (PLDA) and correlate findings to clinical outcomes in dogs receiving thoracolumbar PLDA.
STUDY DESIGN
Blinded study.
ANIMALS
Thirty dogs.
METHODS
Magnetic resonance imaging (MRI) was performed before PLDA (control/Group C), immediately following PLDA (Group I), and 3 months later (perioperative/Group P). Dogs were followed 3 years. Groups and dogs were randomized for evaluation. Two radiologists were blinded to each MRI study and dog. Each radiologist evaluated the disk, vertebral body, and spinal cord at each disk space receiving PLDA.
RESULTS
Mean disk degeneration was increased in Group P at L1-2 (p < .0001) and L2-3 (p = .0081). Both radiologists identified mild diskitis (1%-15%) in Group P (radiologist 1, p < .0001; radiologist 2, p = .0012). Cranial endplate lesions were identified in Group P at T11-12 (p = .0353), T13-L1 (p = .0026), and L4-5 (p = .0210). Lesions were identified in the caudal endplates of all eight disk spaces in Group P: T10-11 (p = .0004), T11-12 (p < .0001), T12-13 (p < .0001), T13-L1 (p < .0001), L1-2 (p < .0001), L2-3 (p < .0001), L3-4 (p < .0001), and L4-5 (p < .0001). There was no disk extrusion or spinal cord lesions identified.
CONCLUSION
This study evaluated effects that may occur secondary to PLDA, using MRI. Although vertebral body changes were identified, they did not correlate with clinical complications.
CLINICAL SIGNIFICANCE
PLDA appears to be a safe, effective procedure performed on thoracolumbar disks to reduce recurrence of intervertebral disk herniation (IVDH) in dogs that previously experienced IVDH, despite the appearance of visible vertebral endplate lesions and mild diskitis on MRI.
Topics: Animals; Dog Diseases; Dogs; Intervertebral Disc; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Lasers; Lumbar Vertebrae; Magnetic Resonance Imaging; Spinal Cord; Vertebral Body
PubMed: 34286854
DOI: 10.1111/vsu.13684 -
Journal of Clinical Medicine Mar 2022In this study, we aimed to assess the potential impact of temporomandibular disk displacement on anatomical structures of the stomatognathic system using biexponential...
In this study, we aimed to assess the potential impact of temporomandibular disk displacement on anatomical structures of the stomatognathic system using biexponential T2 magnetic resonance imaging (MRI) maps. Fifty separate MRI scans of the temporomandibular joints (TMJ) of 25 patients were acquired with eight echo times. Biexponential T2 maps were created by weighted reconstruction based on Powell's conjugate direction method and divided into two groups: the TMJ without (32 images) and with (18 images) disk displacement. The disk, retrodiscal tissue, condylar bone marrow, masseter muscle, lateral and medial pterygoid muscles and dental pulp of the first and second molars were manually segmented twice. The intrarater reliability was assessed. The averages and standard deviations of the T2 times and fractions of each segmented region for each group were calculated and analysed with multiple Student's -tests. Significant differences between groups were observed in the retrodiscal tissue, medial pterygoid muscle and bone marrow. The pulp short T2 component showed a trend toward statistical significance. The segmentation reliability was excellent (93.6%). The relationship between disk displacement and quantitative MRI features of stomatognathic structures can be useful in the combined treatment of articular disk displacement, pterygoid muscle tension and occlusive reconstruction.
PubMed: 35329946
DOI: 10.3390/jcm11061621 -
Indian Journal of Ophthalmology Mar 2023Several characteristic vascular changes can be observed in the glaucomatous eyes, including changes in the vessel configuration and caliber, presence of collateral...
BACKGROUND
Several characteristic vascular changes can be observed in the glaucomatous eyes, including changes in the vessel configuration and caliber, presence of collateral vessel on disk, and disk hemorrhage.
PURPOSE
This video describes characteristic vascular changes in the optic nerve head, which can be observed on clinical examination in the glaucomatous eyes, and useful teaching points to identify the same.
SYNOPSIS
In glaucoma, as the optic cup enlarges, the normal pattern and course of retinal vessels on the optic disk are altered and show characteristic changes. Identification of these changes provides a clue to the presence of cupping.
HIGHLIGHTS
In this video, the vascular changes and its identification in the glaucomatous disc are described, which would be useful to the residents.
VIDEO LINK
https://youtu.be/2eINumBx33E.
Topics: Humans; Glaucoma; Optic Disk; Physical Examination; Retinal Vessels
PubMed: 36872755
DOI: 10.4103/ijo.IJO_2621_22