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EJNMMI Physics Jul 2024Several factors may decrease the accuracy of quantitative PET myocardial perfusion imaging (MPI). It is therefore essential to ensure that myocardial blood flow (MBF)...
BACKGROUND
Several factors may decrease the accuracy of quantitative PET myocardial perfusion imaging (MPI). It is therefore essential to ensure that myocardial blood flow (MBF) values are reproducible and accurate, and to design systematic protocols to achieve this. Until now, no systematic phantom protocols have been available to assess the technical factors affecting measurement accuracy and reproducibility in MPI.
MATERIALS AND METHODS
We implemented a standard measurement protocol, which applies a flow phantom in order to compare image-derived flow values with respect to a ground truth flow value with [O]HO MPI performed on both a Discovery MI (DMI-20, GE Healthcare) and a Biograph Vision 600 (Vision-600, Siemens Healthineers) system. Both systems have automatic [O]HO radio water generators (Hidex Oy) individually installed, allowing us to also study the differences occurring due to two different bolus delivery systems. To investigate the technical factors contributing to the modelled flow values, we extracted the [O]HO bolus profiles, the flow values from the kinetic modeling (Qin and Qout), and finally calculated their differences between test-retest measurements on both systems.
RESULTS
The measurements performed on the DMI-20 system produced Qin and Qout values corresponging to each other as well as to the reference flow value across all test-retest measurements. The repeatability differences on DMI-20 were 2.1% ± 2.6% and 3.3% ± 4.1% for Qin and Qout, respectively. On Vision-600 they were 10% ± 8.4% and 11% ± 10% for Qin and Qout, respectively. The measurements performed on the Vision-600 system showed more variation between Qin and Qout values across test-retest measurements and exceeded 15% difference in 7/24 of the measurements.
CONCLUSIONS
A preliminary protocol for measuring the accuracy and reproducibility of flow values in [O]HO MPI between digital PET/CT systems was assessed. The test-retest reproducibility falls below 15% in majority of the measurements conducted between two individual injector systems and two digital PET/CT systems. This study highlights the importance of implementing a standardized bolus injection and delivery protocol and importance of assessing technical factors affecting flow value reproducibility, which should be carefully investigated in a multi-center setting.
PubMed: 38951352
DOI: 10.1186/s40658-024-00654-y -
International Ophthalmology Jul 2024To analyse and compare the clinical characteristics and treatment outcomes of patients with acute angle closure (AAC) who presented before the COVID-19 pandemic, during... (Comparative Study)
Comparative Study
PURPOSE
To analyse and compare the clinical characteristics and treatment outcomes of patients with acute angle closure (AAC) who presented before the COVID-19 pandemic, during the COVID-19 management and after their downgrading.
METHODS
Consecutive AAC patients were recruited from our hospital and divided into three groups: those treated before the COVID-19 pandemic (Group1), during the COVID-19 management (Group2) and after the management downgrade (Group3). The demographic variables, clinical characteristics, treatment methods and therapeutic outcomes of the groups were compared.
RESULTS
When compared to Groups1 and 2, Group3 showed a significantly higher incidence of AAC (0.27%, P < 0.001), a longer time from symptoms to treatment (TST; 160.88 ± 137.05 h, P = 0.031) and worse uncorrected visual acuity (P = 0.009) at presentation. In Group3, 68.9% had a history of COVID-19 and 28.5% developed ocular symptoms of AAC after taking medication for COVID-19 symptoms. The average time from the onset of COVID-19 to the appearance of eye symptoms was 3.21 ± 4.00 days.
CONCLUSIONS
The COVID-19 has had a multifaceted impact on the incidence of AAC. Therefore, it is crucial to strengthen health education on glaucoma, especially AAC. The prevention and timely treatment of AAC should be emphasised to combat global blindness.
Topics: Humans; COVID-19; Male; Female; China; Glaucoma, Angle-Closure; Middle Aged; Aged; SARS-CoV-2; Incidence; Acute Disease; Retrospective Studies; Intraocular Pressure; Visual Acuity
PubMed: 38951270
DOI: 10.1007/s10792-024-03228-0 -
Scientific Reports Jul 2024In this work, we combine the advantages of virtual Small Angle Neutron Scattering (SANS) experiments carried out by Monte Carlo simulations with the recent advances in...
In this work, we combine the advantages of virtual Small Angle Neutron Scattering (SANS) experiments carried out by Monte Carlo simulations with the recent advances in computer vision to generate a tool that can assist SANS users in small angle scattering model selection. We generate a dataset of almost 260.000 SANS virtual experiments of the SANS beamline KWS-1 at FRM-II, Germany, intended for Machine Learning purposes. Then, we train a recommendation system based on an ensemble of Convolutional Neural Networks to predict the SANS model from the two-dimensional scattering pattern measured at the position-sensitive detector of the beamline. The results show that the CNNs can learn the model prediction task, and that this recommendation system has a high accuracy in the classification task on 46 different SANS models. We also test the network with real data and explore the outcome. Finally, we discuss the reach of counting with the set of virtual experimental data presented here, and of such a recommendation system in the SANS user data analysis procedure.
PubMed: 38951158
DOI: 10.1038/s41598-024-65712-y -
BMJ Open Jul 2024Amblyopia is a neurodevelopmental vision disorder typically affecting one eye, resulting in compromised binocular function. While evidence-based treatments exist for...
SPEctacle Correction for the TReatment of Amblyopia (SPECTRA): study protocol for a prospective non-randomised interventional trial in adults with anisometropic/mixed mechanism amblyopia.
INTRODUCTION
Amblyopia is a neurodevelopmental vision disorder typically affecting one eye, resulting in compromised binocular function. While evidence-based treatments exist for children, there are no widely accepted treatments for adults. This trial aims to assess the efficacy of appropriate optical treatment in improving vision and visual functions in adults with amblyopia. This is hypothesised to significantly improve visual acuity of the amblyopic eye and other visual functions.
METHODS AND ANALYSIS
SPEctacle Correction for the TReatment of Amblyopia is a prospective non-randomised interventional trial. The following criteria for amblyopia will be used: best corrected visual acuity (BCVA) in the amblyopic eye of 0.3 to 1.0 (inclusive) logMAR VA and in the fellow eye, 0.1 logMAR or better, with an interocular VA difference of ≥2 logMAR lines. Eligible participants aged 18-39 will receive full/near-full optical treatment requiring wear for at least half their waking hours for the trial duration. A difference of ≥1.00D spherical equivalent between a participant's current refractive correction and the study prescription is required for eligibility. Primary outcome is the change in amblyopic eye BCVA from baseline to 24-week postenrolment. Secondary outcomes include distance and near VA of both eyes, stereoacuity, contrast sensitivity, interocular suppression, angle of strabismus and fixation stability measured at monthly intervals. Visual evoked potentials will also be measured at baseline, week 12 and week 24. Treatment compliance and quality of life for all participants will be monitored.Analyses comparing baseline and week 24 will utilise pairwise comparisons. Linear mixed models will be fitted to the data for measures taken monthly. This allows estimates and inferences to be drawn from the coefficients of the model, while handling missing data.
ETHICS AND DISSEMINATION
Human ethics approval was obtained from the respective ethics board of the Hong Kong Polytechnic University (HSEARS20210915002) and the University of Waterloo (#44235). The study protocol will conform to the principles of the Declaration of Helsinki. Results will be disseminated through peer-reviewed journals and conferences.
TRIAL REGISTRATION NUMBER
NCT05394987; clinicaltrials.org.
Topics: Humans; Amblyopia; Eyeglasses; Visual Acuity; Prospective Studies; Adult; Young Adult; Adolescent; Male; Female; Treatment Outcome; Non-Randomized Controlled Trials as Topic; Vision, Binocular
PubMed: 38950991
DOI: 10.1136/bmjopen-2023-080151 -
Clinical & Experimental Ophthalmology Jul 2024
Topics: Humans; Myopia; Child; Refraction, Ocular
PubMed: 38950909
DOI: 10.1111/ceo.14391 -
Translational Vision Science &... Jul 2024To evaluate the relationships among morphology, fundus autofluorescence (FAF), and retinal sensitivity of photocoagulated lesions more than 1 year after panretinal...
PURPOSE
To evaluate the relationships among morphology, fundus autofluorescence (FAF), and retinal sensitivity of photocoagulated lesions more than 1 year after panretinal photocoagulation in patients with proliferative diabetic retinopathy and good vision.
METHODS
This retrospective cohort study included patients with proliferative diabetic retinopathy who had undergone panretinal photocoagulation more than 1 year ago. The photocoagulated lesions were classified according to FAF levels: group A, no FAF; group B, diffuse FAF; group C, white-dotted centers with diffuse FAF; group D, white-dotted centers without FAF; and group E, controls. The main outcome measures were FAF, retinal sensitivity, and morphology of the photocoagulated lesions.
RESULTS
The median sensitivity values and number of photocoagulated lesions in groups A (n = 37), B (n = 39), C (n = 4), D (n = 15), and E (n = 39) were 0 dB, 18.0 dB, 13.9 dB, 0.3 dB, and 21.5 dB, respectively. EZ lines were absent in 93.5%, 18.1%, 50%, 93.3%, and 0% of lesions in groups A, B, C, D, and E, respectively. The inner retinal layer was damaged in 45.2%, 3.0%, 50%, 73.3%, and 0% lesions in groups A, B, C, D, and E, respectively. Statistically significant between-group differences were observed in the retinal sensitivities of the photocoagulated lesions, presence of EZ lines, and damage to the inner retinal layer (p < 0.05).
CONCLUSIONS
The photoreceptors in most photocoagulated lesions with diffuse FAF retain their morphology and function.
TRANSLATIONAL RELEVANCE
Using fundus autofluorescence, the damage to photoreceptors after panretinal photocoagulation in patients with diabetes can be estimated in a noninvasive manner. This process can help in determining the need for additional panretinal photocoagulation.
Topics: Humans; Diabetic Retinopathy; Retrospective Studies; Female; Male; Middle Aged; Retina; Aged; Visual Acuity; Fundus Oculi; Fluorescein Angiography; Adult; Laser Coagulation; Optical Imaging
PubMed: 38949634
DOI: 10.1167/tvst.13.7.1 -
Translational Vision Science &... Jul 2024We sought to evaluate the efficacy of growth differentiation factor (GDF)-15 treatment for suppressing epithelial-mesenchymal transition (EMT) and alleviating...
PURPOSE
We sought to evaluate the efficacy of growth differentiation factor (GDF)-15 treatment for suppressing epithelial-mesenchymal transition (EMT) and alleviating transforming growth factor β2 (TGFβ2)-induced lens opacity.
METHODS
To test whether GDF-15 is a molecule that prevents EMT, we pretreated the culture with GDF-15 in neural progenitor cells, retinal pigment epithelial cells, and lens epithelial cells and then treated with factors that promote EMT, GDF-11, and TGFβ2, respectively. To further investigate the efficacy of GDF-15 on alleviating lens opacity, we used mouse lens explant culture to mimic secondary cataracts. We pretreated the lens culture with GDF-15 and then added TGFβ2 to develop lens opacity (n = 3 for each group). Western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to measure EMT protein and gene expression, respectively.
RESULTS
In cell culture, GDF-15 pretreatment significantly attenuated EMT marker expression in cultured cells induced by treatment with GDF-11 or TGFβ2. In the lens explant culture, GDF-15 pretreatment also reduced mouse lens opacity induced by exposure to TGFβ2.
CONCLUSIONS
Our results indicate that GDF-15 could alleviate TGFβ2-induced EMT and is a potential therapeutic agent to slow or prevent posterior capsular opacification (PCO) progression after cataract surgery.
TRANSLATIONAL RELEVANCE
Cataracts are the leading cause of blindness worldwide, with the only current treatment involving surgical removal of the lens and replacement with an artificial lens. However, PCO, also known as secondary cataract, is a common complication after cataract surgery. The development of an adjuvant that slows the progression of PCO will be beneficial to the field of anterior complications.
Topics: Animals; Epithelial-Mesenchymal Transition; Transforming Growth Factor beta2; Growth Differentiation Factor 15; Cataract; Mice; Lens, Crystalline; Mice, Inbred C57BL; Cells, Cultured; Disease Models, Animal; Epithelial Cells; Blotting, Western; Retinal Pigment Epithelium
PubMed: 38949633
DOI: 10.1167/tvst.13.7.2 -
CNS Neuroscience & Therapeutics Jul 2024To investigate the alterations of the optic nerve and visual cortex in dysthyroid optic neuropathy (DON), a subgroup of thyroid eye disease (TED).
AIMS
To investigate the alterations of the optic nerve and visual cortex in dysthyroid optic neuropathy (DON), a subgroup of thyroid eye disease (TED).
METHODS
Multiple orbital imaging biomarkers related to optic nerve compression and the amplitude of low-frequency fluctuations (ALFF) of the brain were obtained from 47 patients with DON, 56 TED patients without DON (nDON), and 37 healthy controls (HC). Correlation analyses and diagnostic tests were implemented.
RESULTS
Compared with HC, the nDON group showed alterations in orbital imaging biomarkers related to optic nerve compression in posterior segments, as well as ALFF of the right inferior temporal gyrus and left fusiform gyrus. DON differed from nDON group mainly in the modified muscle index of the posterior segment of optic nerve, and ALFF of orbital part of right superior frontal gyrus, right hippocampus, and right superior temporal gyrus. Orbital and brain imaging biomarkers were significantly correlated with each other. Diagnostic models attained an area under a curve of 0.80 for the detection of DON.
CONCLUSION
The combined orbital and brain imaging study revealed alterations of the visual pathway in patients with TED and DON as well as provided diagnostic value. The initiation of alterations in the visual cortex in TED may precede the onset of DON.
Topics: Humans; Male; Female; Middle Aged; Graves Ophthalmopathy; Visual Cortex; Adult; Magnetic Resonance Imaging; Optic Nerve Diseases; Orbit; Optic Nerve; Aged
PubMed: 38948947
DOI: 10.1111/cns.14820 -
World Journal of Experimental Medicine Jun 2024Knowledge about refractive stabilization and the accuracy of postoperative refractive error measurements are crucial for improved patient outcomes after...
BACKGROUND
Knowledge about refractive stabilization and the accuracy of postoperative refractive error measurements are crucial for improved patient outcomes after phacoemulsification. Existing guidelines typically recommend waiting 4-6 wk before prescribing corrective lenses. Our research focused on identifying factors that influence refractive errors in the early stages of post-cataract surgery, thus contributing to the existing literature on this topic.
AIM
To investigate the time required for refraction stability after uneventful phacoemulsification surgery.
METHODS
We compared the variation and statistical significance of the difference in spherical, cylindrical components, and the spherical equivalent between the 1- and 6-wk follow-up period in a group of 257 eyes that underwent uneventful phacoemulsification with foldable intraocular lens implantation, all performed by a single experienced surgeon. The Wilcoxon-Signed Rank Test was utilized to assess the magnitude of the change and determine its statistical significance. The refractive stability was defined as the point at which the change in spherical equivalent was within ± 0.5 dioptres for two consecutive visits.
RESULTS
The average age of the patients was 64.9 ± 8.9 yr. The differences observed in both the visits in spherical power (0.1 ± 0.2), cylinder power (0.3 ± 0.4), and spherical equivalent (0.2 ± 0.2) were minimal and not statistically significant. The majority of eyes (93.4%) achieved refractive stability within 6 wk after the surgery. The cylindrical power differed between age groups at the 6 wk post-operative and the difference was statistically significant ( value 0.013). There were no significant differences in refractive stability when considering sex and axial length.
CONCLUSION
Phacoemulsification with foldable intraocular lens implantation results in no significant changes in refraction for the majority of cases during the 6-wk follow-up period. Therefore, a spectacle prescription can be given at the completion of 1 wk.
PubMed: 38948423
DOI: 10.5493/wjem.v14.i2.95016 -
Belitung Nursing Journal 2024Diabetic retinopathy (DR) is the most common microvascular complication of diabetes, leading to visual impairment and eventual blindness. Promoting self-care behaviors...
Effect of a self-care promoting program on engagement in self-care behaviors and health-related outcomes among persons with type 2 diabetes and diabetic retinopathy: A single-blind randomized controlled trial.
BACKGROUND
Diabetic retinopathy (DR) is the most common microvascular complication of diabetes, leading to visual impairment and eventual blindness. Promoting self-care behaviors is crucial in controlling DR progression and preventing blindness.
OBJECTIVE
This study aimed to investigate the effects of a Self-Care Promoting Program (SCPP) on engagement in self-care behaviors, HbA1c levels, visual acuity (VA), severity of DR, and vision-related quality of life (VRQoL) among individuals with type 2 diabetes and DR.
METHODS
This study employed a single-blind randomized controlled trial design to compare SCPP with conventional diabetic care interventions (standard care). The SCPP was based on the Self-Care of Chronic Illness Theory, Self-efficacy theory, and the Association of Diabetic Care and Education Specialist (ADCES) guidelines incorporating health education, self-care maintenance, monitoring, and management skills training over 12 weeks. Ninety-eight participants were randomly allocated to the experimental or control group ( = 49 per group). While the experimental group received SCPP alongside standard care, the control group received standard care alone. Data collection occurred between May 2022 and March 2023 and included demographic information, the Self-Care of Diabetes Index questionnaire (SCODI), the self-care for diabetes eye care questionnaire (SCFDE), the impact of visual impairment questionnaire (IVI-Thai version), and retinal images for DR severity grading. Data analysis utilized descriptive statistics, Chi-Square tests, -tests, and MANOVA.
RESULTS
Following 8 and 16 weeks of SCPP, the experimental group had significantly higher mean scores in engagement with self-care and eye-care behaviors compared to the control group ( <0.001). The highest scores were observed in self-care and eye-care confidence behaviors, followed by maintenance, monitoring, and management. Furthermore, HbA1c levels and VRQoL significantly decreased and were lower than those of the control group at week 16 ( <0.001 and <0.05, respectively). However, there were no significant differences in VA, and DR severity increased in both groups by week 16.
CONCLUSION
SCPP benefits individuals with DR, enhancing their confidence and ability to perform, monitor, and manage self-care behaviors. These strategies contribute to improved diabetes management, enhanced quality of life, and reduced DR-related blindness. Integrating SCPP into routine DR management is recommended, with nurses playing a pivotal role in overseeing and driving this integration, highlighting the critical role of nurses in managing this widespread global disease.
TRIAL REGISTRY NUMBER
Thai Clinical Trials Registration (TCTR20230302002).
PubMed: 38947309
DOI: 10.33546/bnj.3360