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1.
Retina ; 39(7): 1410-1415, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29624544

RESUMO

PURPOSE: To determine whether preoperative adjustments are required for intraocular lens calculations in combined phacovitrectomy surgery. METHODS: A single-center, retrospective study of 50 eyes that underwent combined phacovitrectomy and a control group of 50 eyes after cataract surgery over a 3-year period by a single anterior segment surgeon and a single posterior segment surgeon. Main outcome measures were predicted refractive error (RE), as determined by SRK/T and Holladay 1 formulas, change compared with actual RE, surgically induced astigmatism, and the relationships between preoperative central foveal thickness or change in central foveal thickness and final RE. RESULTS: The differences in predicted and final RE between groups were not statistically significant between groups when both SRK/T and Holladay 1 formulas were used (P > 0.05). Regardless of the formula used, final RE was neither significantly hyperopic nor myopic as compared to the target. There was no difference in surgically induced astigmatism between the two groups. Increased preoperative central foveal thickness was correlated with greater difference between predicted and actual RE. No relationship was noted between change in central foveal thickness and RE. CONCLUSION: Combined phacovitrectomy for concurrent cataract epiretinal membrane by experienced cataract and vitreoretinal surgeons seems to deliver as predictable refractive results as cataract surgery alone.


Assuntos
Catarata/complicações , Membrana Epirretiniana/cirurgia , Lentes Intraoculares , Facoemulsificação/métodos , Refração Ocular/fisiologia , Acuidade Visual , Vitrectomia/métodos , Idoso , Catarata/diagnóstico , Catarata/fisiopatologia , Membrana Epirretiniana/complicações , Membrana Epirretiniana/diagnóstico , Feminino , Humanos , Masculino , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento
2.
J Cell Physiol ; 231(2): 288-94, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26201832

RESUMO

The endoplasmic reticulum (ER) is a critical organelle for normal cell function and homeostasis. Disturbance in the protein folding process in the ER, termed ER stress, leads to the activation of unfolded protein response (UPR) that encompasses a complex network of intracellular signaling pathways. The UPR can either restore ER homeostasis or activate pro-apoptotic pathways depending on the type of insults, intensity and duration of the stress, and cell types. ER stress and the UPR have recently been linked to inflammation in a variety of human pathologies including autoimmune, infectious, neurodegenerative, and metabolic disorders. In the cell, ER stress and inflammatory signaling share extensive regulators and effectors in a broad spectrum of biological processes. In spite of different etiologies, the two signaling pathways have been shown to form a vicious cycle in exacerbating cellular dysfunction and causing apoptosis in many cells and tissues. However, the interaction between ER stress and inflammation in many of these diseases remains poorly understood. Further understanding of the biochemistry, cell biology, and physiology may enable the development of novel therapies that spontaneously target these pathogenic pathways.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Inflamação/fisiopatologia , Apoptose , Autoimunidade/fisiologia , Homeostase , Humanos , Infecções/fisiopatologia , Inflamação/patologia , Doenças Metabólicas/fisiopatologia , Doenças do Sistema Nervoso/fisiopatologia , Transdução de Sinais , Resposta a Proteínas não Dobradas
3.
Transl Vis Sci Technol ; 13(1): 26, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38285459

RESUMO

Purpose: Demonstrate that a novel Bayesian hierarchical spatial longitudinal (HSL) model improves estimation of local macular ganglion cell complex (GCC) rates of change compared to simple linear regression (SLR) and a conditional autoregressive (CAR) model. Methods: We analyzed GCC thickness measurements within 49 macular superpixels in 111 eyes (111 patients) with four or more macular optical coherence tomography scans and two or more years of follow-up. We compared superpixel-patient-specific estimates and their posterior variances derived from the latest version of a recently developed Bayesian HSL model, CAR, and SLR. We performed a simulation study to compare the accuracy of intercept and slope estimates in individual superpixels. Results: HSL identified a significantly higher proportion of significant negative slopes in 13/49 superpixels and a significantly lower proportion of significant positive slopes in 21/49 superpixels than SLR. In the simulation study, the median (tenth, ninetieth percentile) ratio of mean squared error of SLR [CAR] over HSL for intercepts and slopes were 1.91 (1.23, 2.75) [1.51 (1.05, 2.20)] and 3.25 (1.40, 10.14) [2.36 (1.17, 5.56)], respectively. Conclusions: A novel Bayesian HSL model improves estimation accuracy of patient-specific local GCC rates of change. The proposed model is more than twice as efficient as SLR for estimating superpixel-patient slopes and identifies a higher proportion of deteriorating superpixels than SLR while minimizing false-positive detection rates. Translational Relevance: The proposed HSL model can be used to model macular structural measurements to detect individual glaucoma progression earlier and more efficiently in clinical and research settings.


Assuntos
Glaucoma , Humanos , Teorema de Bayes , Glaucoma/diagnóstico , Olho , Nonoxinol , Tomografia de Coerência Óptica
4.
Am J Ophthalmol ; 253: 181-188, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37150336

RESUMO

PURPOSE: To compare rates of change (RoC) of peripapillary retinal nerve fiber layer (RNFL) and Bruch membrane opening-based minimum rim width (BMO-MRW) thickness in moderate-to-advanced glaucoma. DESIGN: Prospective cohort study. METHODS: Longitudinal optical coherence tomography (OCT) optic nerve head volume scans of 113 eyes of 113 glaucoma patients with moderate-to-advanced or central damage were exported. This study estimated and compared global and sectoral RoC with linear mixed effects models and simple linear regression (SLR) of RNFL and BMO-MRW thickness. Permutation analyses were used to test significance of RoC in the SLR model. It also compared longitudinal signal-to-noise ratios (LSNR) defined as RoC divided by residual standard deviation (SD) between the two groups. RESULTS: Mean (SD) follow-up and median (IQR) OCT scan sessions were 5.2 (1.3) years and 10 (8-11), respectively. Baseline average (SD) visual field mean deviation was -9.2 (5.8) dB. Based on SLR, a higher proportion of significant negative RNFL RoC was observed compared to BMO-MRW in the inferotemporal (35% vs 20%; P = .015) and inferonasal (42% vs 17%; P < .001) sectors. Permutation analyses also demonstrated a higher proportion of worsening RNFL RoC than BMO-MRW in the inferotemporal (P = .026) and inferonasal (P < .001) sectors along with overall lower positive RoC. Longitudinal signal-to-noise ratios for RNFL were significantly more negative than for BMO-MRW globally, and in the inferotemporal, inferonasal, and superonasal sectors (P ≤ .01). CONCLUSIONS: Longitudinal RNFL OCT measurements are more likely to detect structural change and demonstrate better LSNR compared with BMO-MRW in eyes with central or moderate-to-advanced glaucoma damage at baseline.


Assuntos
Lâmina Basilar da Corioide , Glaucoma , Retina , Fibras Nervosas/patologia , Nervo Óptico , Humanos , Tomografia de Coerência Óptica , Estudos Prospectivos , Estudos de Coortes , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais
5.
Ophthalmol Sci ; 2(3): 100187, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36245763

RESUMO

Purpose: To investigate spatiotemporal correlations among ganglion cell complex (GCC) superpixel thickness measurements and explore underlying patterns of longitudinal change across the macular region. Design: Longitudinal cohort study. Subjects: One hundred eleven eyes from 111 subjects from the Advanced Glaucoma Progression Study with ≥ 4 visits and ≥ 2 years of follow-up. Methods: We further developed our proposed Bayesian hierarchical model for studying longitudinal GCC thickness changes across macular superpixels in a cohort of glaucoma patients. Global priors were introduced for macular superpixel parameters to combine data across superpixels and better estimate population slopes and intercepts. Main Outcome Measures: Bayesian residual analysis to inspect cross-superpixel correlations for subject random effects and residuals. Principal component analysis (PCA) to explore underlying patterns of longitudinal macular change. Results: Average (standard deviation [SD]) follow-up and baseline 10-2 visual field mean deviation were 3.6 (0.4) years and -8.9 (5.9) dB, respectively. Superpixel-level random effects and residuals had the greatest correlations with nearest neighbors; correlations were higher in the superior than in the inferior region and strongest among random intercepts, followed by random slopes, residuals, and residual SDs. PCA of random intercepts showed a first large principal component (PC) across superpixels that approximated a global intercept, a second PC that contrasted the superior and inferior macula, and a third PC, contrasting inner and nasal superpixels with temporal and peripheral superpixels. PCs for slopes, residual SDs, and residuals were remarkably similar to those of random intercepts. Conclusions: Introduction of cross-superpixel random intercepts and slopes is expected to improve estimation of population and subject parameters. Further model enhancement may be possible by including cross-superpixel random effects and correlations to address spatiotemporal relationships in longitudinal data sets.

6.
J Imaging ; 8(5)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35621903

RESUMO

Reliable biomarkers quantifying neurodegeneration and neuroinflammation in central nervous system disorders such as Multiple Sclerosis, Alzheimer's dementia or Parkinson's disease are an unmet clinical need. Intraretinal layer thicknesses on macular optical coherence tomography (OCT) images are promising noninvasive biomarkers querying neuroretinal structures with near cellular resolution. However, changes are typically subtle, while tissue gradients can be weak, making intraretinal segmentation a challenging task. A robust and efficient method that requires no or minimal manual correction is an unmet need to foster reliable and reproducible research as well as clinical application. Here, we propose and validate a cascaded two-stage network for intraretinal layer segmentation, with both networks being compressed versions of U-Net (CCU-INSEG). The first network is responsible for retinal tissue segmentation from OCT B-scans. The second network segments eight intraretinal layers with high fidelity. At the post-processing stage, we introduce Laplacian-based outlier detection with layer surface hole filling by adaptive non-linear interpolation. Additionally, we propose a weighted version of focal loss to minimize the foreground-background pixel imbalance in the training data. We train our method using 17,458 B-scans from patients with autoimmune optic neuropathies, i.e., multiple sclerosis, and healthy controls. Voxel-wise comparison against manual segmentation produces a mean absolute error of 2.3 µm, outperforming current state-of-the-art methods on the same data set. Voxel-wise comparison against external glaucoma data leads to a mean absolute error of 2.6 µm when using the same gold standard segmentation approach, and 3.7 µm mean absolute error in an externally segmented data set. In scans from patients with severe optic atrophy, 3.5% of B-scan segmentation results were rejected by an experienced grader, whereas this was the case in 41.4% of B-scans segmented with a graph-based reference method. The validation results suggest that the proposed method can robustly segment macular scans from eyes with even severe neuroretinal changes.

7.
Am J Ophthalmol ; 237: 71-82, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34942111

RESUMO

PURPOSE: To test the hypothesis that macular ganglion cell complex (GCC) thickness from optical coherence tomography (OCT) provides a stronger change signal regardless of glaucoma severity compared with other macular measures. DESIGN: Prospective cohort study. METHODS: Eyes were from 112 patients with moderate to severe glaucoma at baseline from a tertiary glaucoma center. In each 3° × 3° macular superpixel, a hierarchical Bayesian random intercept and slope model with random residual variance was fit to longitudinal full macular thickness (FMT), outer retina layers, GCC, ganglion cell-inner plexiform layer (GCIPL), and ganglion cell layer (GCL) measurements. We estimated population- and individual-level slopes and intercepts. Proportions of substantial worsening and improving superpixel slopes were compared between layers and in superpixels with mild to moderate vs severe damage (total deviation of corresponding visual field location ≥ -8 vs < -8 dB). RESULTS: Mean (SD) follow-up time and baseline 10-2 visual field mean deviation were 3.6 (0.4) years and -8.9 (5.9) dB, respectively. FMT displayed the highest proportion of significant negative slopes (1932/3519 [54.9%]), followed by GCC (1286/3519 [36.5%]), outer retina layers (1254/3519 [35.6%]), (GCIPL) (1075/3518 [30.6%]), and (GCL) (698/3518 [19.8%]). Inner macular measures detected less worsening in the severe glaucoma group; yet GCC (223/985 [22.6%]) identified the highest proportion (GCIPL: 183/985 [18.6%]; GCL: 106/985 [10.8%]). Proportions of positive rates were small and comparable among all measures. CONCLUSIONS: GCC is the optimal macular measure for detection of structural change in eyes with moderate to severe glaucoma. Although a higher proportion of worsening superpixels was observed for FMT, a large portion of FMT change could be attributed to changes in outer retina layers.


Assuntos
Glaucoma , Macula Lutea , Teorema de Bayes , Glaucoma/diagnóstico , Humanos , Pressão Intraocular , Estudos Prospectivos , Células Ganglionares da Retina , Tomografia de Coerência Óptica/métodos
8.
JAMA Ophthalmol ; 137(2): 139-145, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30419084

RESUMO

Importance: Macular function is important for daily activities but is underestimated when tested with 24-2 visual fields, which are often used to classify glaucoma severity. Objective: To test the hypothesis that current glaucoma staging systems underestimate glaucoma severity by not detecting macular damage. Design, Setting, and Participants: This cross-sectional study was carried out in a glaucoma referral practice. The eyes of participants with manifest glaucoma and 24-2 mean deviation (MD) better than -6 dB were included. All participants were tested with 24-2, 10-2 visual fields, and spectral-domain optical coherence tomography of the optic disc and macula. Exposures: Macular damage was based on the topographic agreement between visual field results and retinal ganglion cell plus inner plexiform layer probability plots. Classifications from the Hodapp-Parrish-Anderson (HPA), visual field index (VFI), and Brusini staging systems were examined and compared with visual field and spectral-domain optical coherence tomography results. Main Outcomes and Measures: The association between the presence of macular damage and glaucoma severity scores. Results: Fifty-seven eyes of 57 participants were included; 33 participants (57%) were women, and 43 (75%) were white. Their mean (SD) age was 57 (14) years. Forty-eight of the eyes (84% [95% CI, 72%-92%]) had macular damage by the study definition. These had a 24-2 MD mean (SD) of -2.5 (1.8); corresponding results for the 10-2 MD were -3.0 (2.4) dB and for the VFI were 94.2% (4.5%). The HPA system classified 70% (95% CI, 55%-83%) of eyes with macular damage as having early defects; the VFI system classified 81% (95% CI, 67%-91%) of eyes with macular damage as having early defects, and the Brusini system 68% (95% CI, 53%-81%). Conclusions and Relevance: These findings suggest that current glaucoma staging systems based on 24-2 (or 30-2) visual fields underestimate disease severity and the presence of macular damage. If these results are confirmed and generalizable to other participants, new systems using macular measures (from 10-2 and spectral-domain optical coherence tomography results) might improve staging of glaucoma severity.


Assuntos
Glaucoma de Ângulo Aberto/classificação , Glaucoma de Ângulo Aberto/diagnóstico , Transtornos da Visão/diagnóstico , Campos Visuais/fisiologia , Estudos Transversais , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Disco Óptico/diagnóstico por imagem , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica/métodos , Transtornos da Visão/fisiopatologia , Acuidade Visual/fisiologia , Testes de Campo Visual/métodos
9.
Am J Ophthalmol Case Rep ; 10: 233-235, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29780940

RESUMO

PURPOSE: Since its report in one patient more than 70 years ago, digitalis-induced colored muscae volitantes have not surfaced again in the literature. We report here a case of digoxin induced colored floaters. OBSERVATIONS: An 89-year-old man on 0.25 mg digoxin daily developed visual hallucinations and colored floaters. He had floaters in the past but now they were in various colors including yellow, green, blue and red, though predominantly in yellow. These "weirdly" shaped little particles wiggled around as if in a viscous solution and casted shadows in his vision. He also saw geometric shapes, spirals, and cross hatch patterns of various colors that moved and undulated, especially on wallpaper. Ophthalmic examination revealed reduced visual acuity, poor color vision especially in his left eye, along with central depression on Amsler grid and Humphrey visual field in his left eye. Discontinuation of digoxin resulted in complete resolution of his visual symptoms. On subsequent ophthalmic examination, the patient's visual acuity, field testing and color vision improved and he had normal Amsler grid test results. CONCLUSIONS AND IMPORTANCE: Colored floaters may occur in patients taking cardiac glycosides but this association has not been explored. Unlike optical illusions and visual hallucinations, floaters are entoptic phenomena casting a physical shadow upon the retina and their coloring likely arise from retinal dysfunction. Colored floaters may be a more common visual phenomenon than realized.

10.
Australas J Ageing ; 37(1): E33-E36, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29341376

RESUMO

OBJECTIVE: This study investigated the effects of Playback Theatre on older adults' cognitive function and well-being, specifically in the Singapore context. METHODS: Eighteen healthy older adults, older than 50 years of age, participated in the study. Due to practical limitations, a single-group pre-post study design was adopted. Participants completed the outcome measures before and after the training program. There were six weekly sessions in total (about 1.5 hours, once weekly). RESULTS: Participants experienced a significant improvement in their emotional well-being after training. However, there were no significant changes in participants' cognitive function or health-related quality of life. CONCLUSION: Our results suggest that Playback Theatre as a community program has potential to improve the mental and emotional well-being of older people.


Assuntos
Cognição , Envelhecimento Cognitivo/psicologia , Serviços Comunitários de Saúde Mental/métodos , Drama , Qualidade da Assistência à Saúde , Fatores Etários , Emoções , Função Executiva , Feminino , Processos Grupais , Humanos , Masculino , Memória , Saúde Mental , Pessoa de Meia-Idade , Dados Preliminares , Qualidade de Vida , Desempenho de Papéis , Singapura
11.
JACC Cardiovasc Imaging ; 9(4): 376-84, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27056156

RESUMO

OBJECTIVES: The aim of this study was to investigate gender-based differences in nuclear cardiology practice globally, with a particular focus on laboratory volume, radiation dose, protocols, and best practices. BACKGROUND: It is unclear whether gender-based differences exist in radiation exposure for nuclear cardiology procedures. METHODS: In a large, multicenter, observational, cross-sectional study encompassing 7,911 patients in 65 countries, radiation effective dose was estimated for each examination. Patient-level best practices relating to radiation exposure were compared between genders. Analysis of covariance was used to determine any difference in radiation exposure according to gender, region, and the interaction between gender and region. Linear, logistic, and hierarchical regression models were developed to evaluate gender-based differences in radiation exposure and laboratory adherence to best practices. The study also included the United Nations Gender Inequality Index and Human Development Index as covariates in multivariable models. RESULTS: The proportion of myocardial perfusion imaging studies performed in women varied among countries; however, there was no significant correlation with the Gender Inequality Index. Globally, mean effective dose for nuclear cardiology procedures was only slightly lower in women (9.6 ± 4.5 mSv) than in men (10.3 ± 4.5 mSv; p < 0.001), with a difference of only 0.3 mSv in a multivariable model adjusting for patients' age and weight. Stress-only imaging was performed more frequently in women (12.5% vs. 8.4%; p < 0.001); however, camera-based dose reduction strategies were used less frequently in women (58.6% vs. 65.5%; p < 0.001). CONCLUSIONS: Despite significant worldwide variation in best practice use and radiation doses from nuclear cardiology procedures, only small differences were observed between genders worldwide. Regional variations noted in myocardial perfusion imaging use and radiation dose offer potential opportunities to address gender-related differences in delivery of nuclear cardiology care.


Assuntos
Disparidades em Assistência à Saúde , Cardiopatias/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Tomografia por Emissão de Pósitrons , Doses de Radiação , Exposição à Radiação , Compostos Radiofarmacêuticos/administração & dosagem , Tomografia Computadorizada de Emissão de Fóton Único , África , Idoso , Ásia , Distribuição de Qui-Quadrado , Circulação Coronária , Estudos Transversais , Europa (Continente) , Feminino , Cardiopatias/fisiopatologia , Humanos , América Latina , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Imagem de Perfusão do Miocárdio/efeitos adversos , América do Norte , Oceania , Razão de Chances , Tomografia por Emissão de Pósitrons/efeitos adversos , Compostos Radiofarmacêuticos/efeitos adversos , Sistema de Registros , Medição de Risco , Fatores de Risco , Fatores Sexuais , Tomografia Computadorizada de Emissão de Fóton Único/efeitos adversos
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