The Effect of Attention on Fixation Stability During Dynamic Fixation Testing in Stargardt Disease

Abstract Aims The aim of this study was to compare the fixation stability and complications in patients undergoing periacetabular osteotomy (PAO) with either K-wire or screw fixation. Patients and methods We performed a retrospective study to analyze a consecutive series of patients who underwent PAO with either screw or K-wire fixation. Patients who were treated for acetabular retroversion or had previous surgery on the ipsilateral hip joint were excluded. 172 patients (191 hips: 99 K-wire/92 screw fixation) were included. The mean age at the time of PAO was 29.3 years (16–48) in the K-wire group and 27.3 (15–45) in the screw group and 83.9% were female. Clinical parameters including duration of surgery, minor complications (soft tissue irritation and implant migration) and major complications (implant failure and non-union) were evaluated. Radiological parameters including LCE, TA and FHEI were measured preoperatively, postoperatively and at 3-months follow-up. Results Duration of surgery was significantly reduced in the K-wire group with 88.2 min (53–202) compared to the screw group with 119.7 min (50–261) (p < 0.001). Soft tissue irritation occurred significantly more often in the K-wire group (72/99) than in the screw group (36/92) (p < 0.001). No group showed significantly more implant migration than the other. No major complications were observed in either group. Postoperative LCE, TA and FHEI were improved significantly in both groups for all parameters (p = < 0.0001). There was no significant difference for initial or final correction for the respective parameters between the two groups. Furthermore, no significant difference in loss of correction was observed between the two groups for the respective parameters. Conclusion K-wire fixation is a viable and safe option for fragment fixation in PAO with similar stability and complication rates as screw fixation. An advantage of the method is the significantly reduced operative time. A disadvantage is the significantly higher rate of implant-associated soft tissue irritation, necessitating implant removal. Level of evidence III, retrospective trial.

Download Full-text

Atrophy Expansion Rates in Stargardt Disease Using Ultra-Widefield Fundus Autofluorescence

Ophthalmology Science ◽

10.1016/j.xops.2021.100005 ◽

2021 ◽

Vol 1 (1) ◽

pp. 100005

Author(s):

Rachael C. Heath Jeffery ◽

Jennifer A. Thompson ◽

Johnny Lo ◽

Tina M. Lamey ◽

Terri L. McLaren ◽

...

Keyword(s):

Fundus Autofluorescence ◽

Stargardt Disease

Download Full-text

A vicious cycle of bisretinoid formation and oxidation relevant to recessive Stargardt disease

Journal of Biological Chemistry ◽

10.1016/j.jbc.2021.100259 ◽

2021 ◽

pp. 100259

Author(s):

Jin Zhao ◽

Hye Jin Kim ◽

Keiko Ueda ◽

Kevin Zhang ◽

Diego Montenegro ◽

...

Keyword(s):

Vicious Cycle ◽

Stargardt Disease

Download Full-text

Post audio-visual biofeedback training visual functions and quality of life in paediatric idiopathic infantile nystagmus: A pilot study

European Journal of Ophthalmology ◽

10.1177/1120672121991048 ◽

2021 ◽

pp. 112067212199104

Author(s):

Monica Daibert-Nido ◽

Yulia Pyatova ◽

Michelle Markowitz ◽

Maryam Taheri-Shirazi ◽

Samuel N Markowitz

Keyword(s):

Quality Of Life ◽

Pilot Study ◽

Contrast Sensitivity ◽

Reading Speed ◽

Biofeedback Training ◽

Visual Functions ◽

Infantile Nystagmus ◽

Fixation Stability ◽

Better Than

Purpose: Biofeedback training (BT) was adapted to idiopathic infantile nystagmus syndrome (IINS) cases to enhance visual functions and quality of life (QoL). Methods: 10 patients (age 9 ± 3.2 years) treated with the audio-visual BT module of the MAIA microperimeter (Centervue, Padova, Italy) were assessed in two baseline visits and 1week post-BT (BT 80 min in total). The outcomes were distance and near binocular best corrected visual acuity (BBCVA), fixation stability, reading speed, contrast sensitivity, stereopsis and Children’s Visual Function Questionnaire. One-way repeated measured ANOVA and paired t-tests were used. Results: Distance BBCVA improved from 0.46 ± 0.21 and 0.43 ± 0.18 pre-BT to 0.33 ± 0.2 logMAR post-BT ( F (2,27) = 13.75, p = 0.0002). Post-BT was better than baseline ( p = 0.0001) and pre-BT ( p = 0.001). Near BBCVA improved from 0.23 ± 0.09 and 0.21 ± 0.14 pre-BT to 0.04 ± 0.08 post-BT (F (2,27) = 22.12, p = 0.000014), post-BT was better than baseline ( p = 0.0001) and pre-BT ( p = 0.0006). Stereopsis improved from 283 ± 338″ to 39 ± 32.2″ ( p = 0.04), contrast sensitivity from 0.26 ± 0.17 to 0.08 ± 0.12 log units ( p = 0.01), and reading speed improved from 74.7 ± 51.2 wpm to 104.7 ± 53.6 wpm ( p = 0.0006). Fixation stability improved from 33.6 ± 28.1 to 14.3 ± 10.1 sq. QoL increased from 23.8 ± 2.2 to 26.3 ± 2.3 units ( p = 0.001). Conclusion: BT benefited all visual functions and QoL in this pilot study, heralding a new possibility for Low Vision Rehabilitation in IINS.

Download Full-text

Antisense Oligonucleotide Screening to Optimize the Rescue of the Splicing Defect Caused by the Recurrent Deep-Intronic ABCA4 Variant c.4539+2001G>A in Stargardt Disease

Genes ◽

10.3390/genes10060452 ◽

2019 ◽

Vol 10 (6) ◽

pp. 452 ◽

Cited By ~ 9

Author(s):

Alejandro Garanto ◽

Lonneke Duijkers ◽

Tomasz Z. Tomkiewicz ◽

Rob W. J. Collin

Keyword(s):

Pluripotent Stem Cells ◽

Antisense Oligonucleotides ◽

Autosomal Recessive ◽

Stargardt Disease ◽

Single Nucleotide ◽

Significant Correction ◽

Nucleotide Mismatch ◽

Single Nucleotide Mismatch ◽

Splicing Defects ◽

Induced Pluripotent

Deep-sequencing of the ABCA4 locus has revealed that ~10% of autosomal recessive Stargardt disease (STGD1) cases are caused by deep-intronic mutations. One of the most recurrent deep-intronic variants in the Belgian and Dutch STGD1 population is the c.4539+2001G>A mutation. This variant introduces a 345-nt pseudoexon to the ABCA4 mRNA transcript in a retina-specific manner. Antisense oligonucleotides (AONs) are short sequences of RNA that can modulate splicing. In this work, we designed 26 different AONs to perform a thorough screening to identify the most effective AONs to correct splicing defects associated with c.4539+2001G>A. All AONs were tested in patient-derived induced pluripotent stem cells (iPSCs) that were differentiated to photoreceptor precursor cells (PPCs). AON efficacy was assessed through RNA analysis and was based on correction efficacy, and AONs were grouped and their properties assessed. We (a) identified nine AONs with significant correction efficacies (>50%), (b) confirmed that a single nucleotide mismatch was sufficient to significantly decrease AON efficacy, and (c) found potential correlations between efficacy and some of the parameters analyzed. Overall, our results show that AON-based splicing modulation holds great potential for treating Stargardt disease caused by splicing defects in ABCA4.

Download Full-text

Recessive multiple epiphyseal dysplasia and Stargardt disease in two sisters

Molecular Genetics & Genomic Medicine ◽

10.1002/mgg3.1630 ◽

2021 ◽

Author(s):

Leonardo Gatticchi ◽

Dominika Vešelényiová ◽

Jan Miertus ◽

Paolo Enrico Maltese ◽

Elena Manara ◽

...

Keyword(s):

Multiple Epiphyseal Dysplasia ◽

Stargardt Disease ◽

Epiphyseal Dysplasia

Download Full-text

Study and Analysis of Mechanical Behavior between Rigid and Dynamic Fixation Systems Analyzed by the Finite Element Method

Journal of Biomimetics Biomaterials and Biomedical Engineering ◽

10.4028/www.scientific.net/jbbbe.33.12 ◽

2017 ◽

Vol 33 ◽

pp. 12-31 ◽

Cited By ~ 1

Author(s):

Samir Zahaf ◽

Said Kebdani

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Intervertebral Disc ◽

Spinal Diseases ◽

Main Role ◽

Rigid Fixation ◽

Dynamic Fixation ◽

Motion Segment ◽

Fixation Devices ◽

Element Method

Orthopedic fixation devices are widely used in treatment of spinal diseases. It is expected that application of dynamic stabilization confers valuable movement possibility besides its main role of load bearing. Comparative investigation between pedicle screw model rigid fixation and (B Dyne, Elaspine, Bioflex, Coflexe rivet) models dynamic fixation systems may elucidate the efficacy of each design. The goal of the present study is to evaluate the efficacy of five fixation systems mounted on L4-L5 motion segment. In this numerical study, a 3D precious model of L4, L5 and their intervertebral disc has been employed based on CT images. five fixation devices have been also implanted internally to the motion segment. Finite element method was used to evaluate stress distribution in the disc and determine the overall displacement of the segment as a measure of movement possibility. The results show that The Coflex rivet implantation can provide stability in all motions and reduce disc annulus stress at the surgical segment (L4-L5), on the other hand, Maximum stress in the disc has been observed in dynamic systems but within the safe range. The greater movement of the motion segment has been also appeared in dynamic fixations. Existence of the fixation systems reduced the stress on the intervertebral disc which might be exerted in intact cases. Use of the fixation devices can considerably reduce the load on the discs and prepare conditions for healing of the injured ones. Furthermore, dynamic modes of fixation confer possibility of movement to the motion segments in order to facilitate the spinal activities.

Download Full-text