Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 162
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Article in English | MEDLINE | ID: mdl-38754979

ABSTRACT

BACKGROUND: Research on cognitive rehabilitation (CR) and aerobic exercise (EX) to improve cognition in progressive multiple sclerosis (PMS) remains limited. CogEx trial investigated the effectiveness of CR and EX in PMS: here, we present MRI substudy volumetric and task-related functional MRI (fMRI) findings. METHODS: Participants were randomised to: 'CR plus EX', 'CR plus sham EX (EX-S)', 'EX plus sham CR (CR-S)' and 'CR-S plus EX-S' and attended 12-week intervention. All subjects performed physical/cognitive assessments at baseline, week 12 and 6 months post intervention (month 9). All MRI substudy participants underwent volumetric MRI and fMRI (Go-NoGo task). RESULTS: 104 PMS enrolled at four sites participated in the CogEx MRI substudy; 84 (81%) had valid volumetric MRI and valid fMRI. Week 12/month 9 cognitive performances did not differ among interventions; however, 25-62% of the patients showed Symbol Digit Modalities Test improvements. Normalised cortical grey matter volume (NcGMV) changes at week 12 versus baseline were heterogeneous among interventions (p=0.05); this was mainly driven by increased NcGMV in 'CR plus EX-S' (p=0.02). Groups performing CR (ie, 'CR plus EX' and 'CR plus EX-S') exhibited increased NcGMV over time, especially in the frontal (p=0.01), parietal (p=0.04) and temporal (p=0.04) lobes, while those performing CR-S exhibited NcGMV decrease (p=0.008). In CR groups, increased NcGMV (r=0.36, p=0.01) at week 12 versus baseline correlated with increased California Verbal Learning Test (CVLT)-II scores. 'CR plus EX-S' patients exhibited Go-NoGo activity increase (p<0.05, corrected) at week 12 versus baseline in bilateral insula. CONCLUSIONS: In PMS, CR modulated grey matter (GM) volume and insular activity. The association of GM and CVLT-II changes suggests GM plasticity contributes to cognitive improvements. TRIAL REGISTRATION NUMBER: NCT03679468.

2.
Graefes Arch Clin Exp Ophthalmol ; 262(3): 813-822, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37955702

ABSTRACT

PURPOSE: The purpose of this study is to investigate test-retest reliability and agreement of the quantitative contrast sensitivity function test (qCSF) in the retina clinic. METHODS: A total of 121 right eyes of 121 patients were tested and consecutively re-tested with qCSF in the retina clinic. Outcomes included area under the logarithm of contrast sensitivity function curve (AULCSF), contrast acuity, and contrast sensitivity thresholds at 1-18 cycles per degree (cpd). Test-retest means were compared with paired t-test, variability was compared with the Brown-Forsythe test, and intraclass correlation coefficient (ICC) and Bland Altman plots evaluated reliability and agreement. RESULTS: Mean test-retest differences for all qCSF metrics ranged from 0.02 to 0.05 log units without statistically significant differences in variability. Standard deviations ranged from 0.08 to 0.14. Coefficients of repeatability ranged from 0.16 to 0.27 log units. ICC > 0.9 for all metrics except 1cpd (ICC = 0.84, all p < 0.001); AULCSF ICC = 0.971. CONCLUSION: qCSF-measured contrast sensitivity shows great test-retest repeatability and agreement in the retina clinic.


Subject(s)
Contrast Sensitivity , Vision Tests , Humans , Reproducibility of Results , Retina
3.
Retina ; 44(2): 246-254, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37824814

ABSTRACT

PURPOSE: To determine the correlation between microperimetry and imaging findings in extensive macular atrophy with pseudodrusen-like appearance (EMAP). METHODS: This cross-sectional, observational study included 44 consecutive patients with EMAP (88 eyes) and 30 healthy subjects (60 eyes). Both groups underwent visual acuity assessment, mesopic and scotopic microperimetry, fundus photography, autofluorescence, optical coherence tomography, and optical coherence tomography angiography. Retinal sensitivity was also subdivided in macular (0-4°) and paramacular areas (8-10°). Scotopic sensitivity loss was defined as the difference between scotopic and mesopic sensitivities for each tested point. Eyes with EMAP were further classified into the three stages described by Romano et al: 19 eyes in Stage 1, 31 in Stage 2, and 38 in Stage 3. RESULTS: Mesopic and scotopic retinal sensitivity were significantly reduced in patients with EMAP compared with controls, particularly in the macular area (all P < 0.001). Mesopic retinal sensitivity progressively declined in more advanced EMAP stages (all P < 0.01), but no scotopic differences were observed between Stages 2 and 3 ( P = 0.08). Remarkably, scotopic sensitivity loss was significantly higher in Stage 1 ( P < 0.05).On multivariate analysis, mesopic dysfunction was associated with larger atrophic areas ( P < 0.01), foveal involvement ( P = 0.03), and fibrosis ( P = 0.02). Conversely, no independent variable was associated with a reduced scotopic retinal sensitivity (all P > 0.05). CONCLUSION: The findings highlight that patients with EMAP suffer from a severe cone- and rod-mediated dysfunction on microperimetry. The predominant rod impairment in the early cases (Stage 1) emphasizes the importance of dark-adapted scotopic microperimetry as a clinical end point and suggests defective transportation across the RPE-Bruch membrane complex in its pathogenesis.


Subject(s)
Macular Degeneration , Visual Field Tests , Humans , Visual Field Tests/methods , Cross-Sectional Studies , Retina/pathology , Tomography, Optical Coherence , Atrophy/pathology
4.
Medicina (Kaunas) ; 60(4)2024 Mar 23.
Article in English | MEDLINE | ID: mdl-38674173

ABSTRACT

Artificial intelligence (AI) has emerged as a transformative tool in the field of ophthalmology, revolutionizing disease diagnosis and management. This paper provides a comprehensive overview of AI applications in various retinal diseases, highlighting its potential to enhance screening efficiency, facilitate early diagnosis, and improve patient outcomes. Herein, we elucidate the fundamental concepts of AI, including machine learning (ML) and deep learning (DL), and their application in ophthalmology, underscoring the significance of AI-driven solutions in addressing the complexity and variability of retinal diseases. Furthermore, we delve into the specific applications of AI in retinal diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), Macular Neovascularization, retinopathy of prematurity (ROP), retinal vein occlusion (RVO), hypertensive retinopathy (HR), Retinitis Pigmentosa, Stargardt disease, best vitelliform macular dystrophy, and sickle cell retinopathy. We focus on the current landscape of AI technologies, including various AI models, their performance metrics, and clinical implications. Furthermore, we aim to address challenges and pitfalls associated with the integration of AI in clinical practice, including the "black box phenomenon", biases in data representation, and limitations in comprehensive patient assessment. In conclusion, this review emphasizes the collaborative role of AI alongside healthcare professionals, advocating for a synergistic approach to healthcare delivery. It highlights the importance of leveraging AI to augment, rather than replace, human expertise, thereby maximizing its potential to revolutionize healthcare delivery, mitigate healthcare disparities, and improve patient outcomes in the evolving landscape of medicine.


Subject(s)
Artificial Intelligence , Early Diagnosis , Retinal Diseases , Humans , Retinal Diseases/diagnosis , Diabetic Retinopathy/diagnosis , Machine Learning , Deep Learning , Macular Degeneration/diagnosis
5.
Eur Phys J E Soft Matter ; 46(4): 28, 2023 Apr 12.
Article in English | MEDLINE | ID: mdl-37043075

ABSTRACT

Air jets for active flow control have proved effective in postponing the onset of stall phenomenon in axial compressors. In this paper, we use a combination of machine learning and genetic algorithm to explore the optimal parameters of air jets to control rotating stall in the axial compressor CME2. Three control parameters are investigated: the absolute injection angle, the number of injector pairs and the injection velocity. Given an experimental dataset, the influence of the air jet parameters on the surge margin improvement and power balance is modeled using two shallow neural networks. Parameters of the air jets are then optimized using a genetic algorithm for three rotational velocities, i.e., [Formula: see text]. First, surge margin improvement and power balance are being maximized independently. Then, a bi-objective optimization problem is posed to explore the trade-off between the two competing objectives. Based on the Pareto front, results suggest that a globally optimal set of parameters is obtained for a velocity ratio (defined as the ratio of the injection velocity to the rotor tip speed) ranging from 1.1 to 1.6 and an injection angle attack varying from [Formula: see text]. These outcomes point out a potential generalization of the control strategy applicable to other compressors.

6.
Retina ; 43(3): 402-411, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36727827

ABSTRACT

PURPOSE: To describe the imaging characteristics and topographic expansion of retinal pigment epithelium (RPE) and outer retinal atrophy in extensive macular atrophy with pseudodrusen-like appearance. METHODS: Three-year, prospective, observational study. Nine patients with extensive macular atrophy with pseudodrusen-like appearance (17 eyes; 6 women) with no other ocular conditions were annually examined; one eye was excluded because of macular neovascularization. Best-corrected visual acuity measurement, fundus photographs, blue-light autofluorescence, and optical coherence tomography were performed at each visit. Formation of atrophy was analyzed on optical coherence tomography at foveal and extrafoveal areas following the Classification of Atrophy Meeting recommendations. Spatial enlargement throughout four sectors was assessed on blue-light autofluorescence after placing an Early Treatment for Diabetic Retinopathy Study grid centered on the foveola. RESULTS: Mean age was 53.0 ± 2.1 years at baseline with a follow-up of 36.6 ± 0.7 months. Thinning of the outer nuclear layer and disruption of the ellipsoid zone initially appeared above areas of RPE-Bruch membrane separation and preceded RPE atrophy. Subfoveal fibrosis was seen in 65% of the eyes. Superior sector involvement was found in all patients at baseline and was significantly larger than the other sectors at any time point ( P < 0.001). Best-corrected visual acuity declined from 68.0 ± 15.7 letters to 44.8 ± 14.9 letters during the follow-up and was significantly associated with subfoveal atrophy ( P < 0.001) and fibrosis ( P = 0.02). CONCLUSION: Our findings suggest that primary alterations in patients with extensive macular atrophy with pseudodrusen-like appearance are present at the outer segment-RPE interface, with the superior Early Treatment for Diabetic Retinopathy Study sector being the most vulnerable, which progresses to extensive atrophy of the RPE and outer retinal layers. Accordingly, we propose a three-stage disease classification.


Subject(s)
Diabetic Retinopathy , Macular Degeneration , Humans , Female , Middle Aged , Prospective Studies , Diabetic Retinopathy/pathology , Fluorescein Angiography , Macular Degeneration/pathology , Retinal Pigment Epithelium/pathology , Atrophy/pathology , Tomography, Optical Coherence/methods , Fibrosis
7.
Retina ; 42(10): 1844-1851, 2022 10 01.
Article in English | MEDLINE | ID: mdl-35976222

ABSTRACT

PURPOSE: To report the imaging and functional features of the repair tissue following retinal pigment epithelium (RPE) tears. METHODS: This cross-sectional observational study included patients with RPE tears secondary to neovascular age-related macular degeneration and at least 12 months of follow-up. The following variables were analyzed: best-corrected visual acuity; retinal sensitivity using microperimetry; outer retinal layers status and RPE resurfacing on optical coherence tomography; fibrosis; autofluorescence signal recovery using blue-light and near-infrared autofluorescence. RESULTS: Overall, 48 eyes were included (age: 82 ± 5 years) and 34 of them showed signs of healing. Retinal pigment epithelium resurfacing was noticed in 22 cases, whereas fibrosis appeared in 21 eyes. Autofluorescence improved in 17 cases using blue-light infrared autofluorescence and 7 eyes on near-infrared autofluorescence. Outer retinal layers were more frequently preserved when RPE resurfacing and autofluorescence improvement occurred ( P < 0.05). Although best-corrected visual acuity was higher for smaller RPE tears ( P = 0.01), retinal sensitivity of the healing tissue was positively affected by autofluorescence improvement ( P < 0.001) and by absence of fibrosis ( P = 0.03). CONCLUSION: Autofluorescence signal recovery after rip occurrence possibly reflects the underlying status of the RPE and is associated with better functional outcomes. Our findings highlight the importance of blue-light infrared autofluorescence and especially near-infrared autofluorescence assessment in the setting of rip healing.


Subject(s)
Retinal Pigment Epithelium , Tomography, Optical Coherence , Aged , Aged, 80 and over , Cross-Sectional Studies , Fibrosis , Fluorescein Angiography , Humans , Infant , Multimodal Imaging , Retinal Pigment Epithelium/pathology , Retrospective Studies , Tomography, Optical Coherence/methods , Visual Acuity
8.
Clin Exp Ophthalmol ; 50(5): 500-509, 2022 07.
Article in English | MEDLINE | ID: mdl-35503294

ABSTRACT

BACKGROUND: To measure quantitative autofluorescence (qAF) in patients under treatment with hydroxychloroquine (HCQ) and at risk of retinal toxicity but with no apparent signs of retinal toxicity and to compare it with that of untreated subjects. METHODS: Consecutive patients at risk for the development of HCQ retinal toxicity (duration of treatment >5 years or daily HCQ dose >5 mg/kg of actual body weight [ABW]) but no alterations on spectral domain-optical coherence tomography, short-wavelength autofluorescence and 10-2 visual field examination were recruited. Healthy subjects matched by age and sex were also enrolled in the study. All subjects underwent qAF measurements in one eye. Images were analysed using the conventional qAF grid by Delori calculating the qAF of eight sectors of the intermediate ring and the mean of those values (qAF8 ). RESULTS: Thirty-nine patients treated with HCQ (38 females, mean age 52.1 ± 8.6 years) and 39 untreated subjects (38 females, mean age 51.2 ± 8.6 years) were included. In both HCQ patients and untreated subjects, qAF8 was positively correlated with age (p = 0.004). Although HCQ patients showed a higher mean qAF8 compared with untreated subjects (294.7 ± 65.3 vs. 268.9 ± 57.5), the difference was not significant (p = 0.068). HCQ patients showed significantly higher mean qAF values in the inferior-temporal, inferior and inferior-nasal sectors of the intermediate ring of qAF grid compared with untreated subjects (all p < 0.05). CONCLUSIONS: These results suggest a possible preclinical increase of qAF values in inferior parafoveal sectors probably induced by HCQ exposure.


Subject(s)
Antirheumatic Agents , Retinal Diseases , Adult , Antirheumatic Agents/adverse effects , Female , Fluorescein Angiography/methods , Humans , Hydroxychloroquine/adverse effects , Middle Aged , Retinal Diseases/chemically induced , Retinal Diseases/diagnosis , Retinal Diseases/drug therapy , Tomography, Optical Coherence/methods
9.
Retina ; 41(5): 1010-1017, 2021 May 01.
Article in English | MEDLINE | ID: mdl-32925562

ABSTRACT

PURPOSE: To assess ellipsoid zone (EZ) alterations in Best vitelliform macular dystrophy using spectral-domain optical coherence tomography. METHODS: Prospective, observational case series. Forty-three patients (43 eyes) underwent complete ophthalmological examination at baseline and at 24 months: best-corrected visual acuity (BCVA), biomicroscopy, fundus photography, and spectral-domain optical coherence tomography were performed. Acquisition protocol included 19-line raster scan. Alterations in EZ were marked on spectral-domain optical coherence tomography, and the area was manually calculated on a near-infrared reflectance image. Three patterns were identified: A (decrease >0.25 mm2), B (±0.25 mm2), and C (increase >0.25 mm2). Primary outcome was to describe different patterns of EZ alteration. Secondary outcomes included their correlation with BCVA and the description of a central optically preserved islet. RESULTS: At baseline, altered EZ was identified in 40 eyes. Worse BCVA significantly correlated with larger EZ alterations but not with lesion extension on fundus photograph. Only "pattern-C" eyes unveiled BCVA worsening at follow-up. Optically preserved islet was detected in 16 eyes (37%), disclosing significantly better vision; its disappearance at follow-up (n = 7; 44% of 16 eyes) correlated with a decrease in BCVA. CONCLUSION: The assessment of EZ status might represent a valuable functional marker in Best vitelliform macular dystrophy because stable alterations and the maintenance of a central optically preserved islet are associated with better visual acuity.


Subject(s)
Fluorescein Angiography/methods , Macula Lutea/pathology , Tomography, Optical Coherence/methods , Visual Acuity , Vitelliform Macular Dystrophy/diagnosis , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Prospective Studies , Time Factors , Vitelliform Macular Dystrophy/physiopathology , Young Adult
10.
Am J Otolaryngol ; 42(3): 102934, 2021.
Article in English | MEDLINE | ID: mdl-33526270

ABSTRACT

Spindle cell larynx carcinoma (SpCC) represents around 3% of laryngeal cancers. It is originated by a single cancer stem cell undergoing epithelial to mesenchymal transition. This explains the aggressiveness, the peculiar resistance to conventional therapy and the frequent relapses. We focused on this particular cancer subset characteristics in patients, in early and advanced stages primarily aiming to define and highlight the differences with Laryngeal Squamous Cell Carcinoma (LSCC) focusing on clinical features, treatments, follow-up and survival in a patient's cohort composed by comparable cases from two subgroups.


Subject(s)
Laryngeal Neoplasms/pathology , Sarcoma/pathology , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/pathology , Drug Resistance, Neoplasm , Female , Humans , Laryngeal Neoplasms/mortality , Laryngeal Neoplasms/therapy , Male , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Sarcoma/mortality , Sarcoma/therapy , Survival Rate
11.
Faraday Discuss ; 222(0): 108-121, 2020 Jun 19.
Article in English | MEDLINE | ID: mdl-32101208

ABSTRACT

When functionalised with amines, silicon nanocrystals (SiNCs) are known to have surface-state emission with loss of colour tunability, low quantum yield and short nanosecond lifetimes. These changes in optical properties are produced by direct amine bonding on the silicon surface. In this article, secondary amine functionalised SiNCs with bright, red (λmax = 750 nm) and long-lived emission (τ ca. 50 µs) are reported for the first time via a three-step synthetic approach. These SiNCs are colloidally stable in several polar solvents and can be further functionalised by reaction with carboxylic acid groups. We proved the feasibility of further functionalization with pyrene butyric acid: ca. 40 pyrene units per nanoparticle were attached via amide bond formation. The resulting hybrid system works as a light-harvesting antenna: excitation of pyrene units at 345 nm results in sensitised emission at 700 nm by the silicon core.

12.
Graefes Arch Clin Exp Ophthalmol ; 258(2): 297-301, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31848692

ABSTRACT

PURPOSE: The vitelliform stage is the typical phenotypic manifestation of Best vitelliform macular dystrophy (BVMD). As yet, no study has focused specifically on the clinical changes occurring in the vitelliform stage over the follow-up. METHODS: The survey takes the form of a prospective observational study with a 5-year follow-up. Twenty-one eyes of 11 patients in the vitelliform stage were examined annually. The primary outcome was the identification of the changes in the vitelliform lesion over a 5-year follow-up. Secondary outcomes included changes in structural optical coherence tomography (OCT) parameters and the correlation with the BCVA variation over the follow-up. RESULTS: Spectral domain OCT at baseline showed one subform characterized by solid vitelliform deposition, in 81% of eyes, and another subform characterized by a combination of solid deposition and subretinal fluid, in 19% of eyes. Overall, 62% of eyes showed an increase in the area of vitelliform deposition. Once the maximal area was reached, a progressive flattening of the vitelliform deposition took place, with subsequent flattening of the vitelliform lesion and formation of subretinal fluid. Hyperreflective foci (HF) increased in number as long as the vitelliform area continued to expand, with no variation in HF when the vitelliform lesion flattened or the subretinal fluid formed. CONCLUSIONS: The vitelliform stage reveals more subforms with clinical variations over the follow-up. Our data suggest that the substage before the flattening of the lesion, thus before the so-called subretinal fluid accumulates and when the visual acuity is still high, might offer the best opportunity for an optimal therapeutic approach.


Subject(s)
Fluorescein Angiography/methods , Macula Lutea/pathology , Retinal Vessels/pathology , Tomography, Optical Coherence/methods , Vitelliform Macular Dystrophy/diagnosis , Vitreous Body/pathology , Adolescent , Adult , Child , Disease Progression , Female , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Prospective Studies , Time Factors , Young Adult
13.
Retina ; 40(12): 2263-2269, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32032255

ABSTRACT

PURPOSE: Choroidal neovascularization (CNV) is a common complication of patients affected by age-related macular degeneration, showing a highly variable visual outcome. The main aim of the study was, at baseline, to perform a quantitative optical coherence tomography angiography assessment of CNV secondary to age-related macular degeneration and to assess posttreatment outcomes. METHODS: Seventy-eight naïve age-related macular degeneration-related CNV patients (39 men, mean age 78 ± 8 years) were recruited and underwent complete ophthalmologic evaluation and multimodal imaging. Several OCT and optical coherence tomography angiography parameters were collected, including vessel tortuosity and vessel dispersion (VDisp), measured for each segmented CNV. All patients underwent anti-vascular endothelial growth factor PRN treatment. Vessel tortuosity and VDisp values of CNVs were tested at baseline to establish a cutoff able to distinguish clinically different patient subgroups. RESULTS: Mean best-corrected visual acuity was 0.49 ± 0.57 (20/62) at baseline, improving to 0.31 ± 0.29 (20/41) at the 1-year follow-up (P < 0.01), with a mean number of 6.4 ± 1.9 injections. Our cohort included the following CNV types: occult (45 eyes; 58%), classic (14 eyes; 18%), and mixed (19 eyes; 24%). Observing optical coherence tomography angiography parameters, classic, mixed, and occult CNV revealed significantly different values of VDisp, with classic forms showing the highest values and the occult CNVs showing the lowest (P < 0.01); mixed forms displayed intermediate VDisp values. The ROC analysis revealed that a CNV vessel tortuosity cut-off of 8.40, calculated at baseline, enabled two patient subgroups differing significantly in visual outcomes after anti-vascular endothelial growth factor treatment to be distinguished. CONCLUSION: A baseline quantitative optical coherence tomography angiography-based parameter could provide information regarding both clinical and functional outcomes after anti-vascular endothelial growth factor treatment in age-related macular degeneration-related CNV.


Subject(s)
Choroidal Neovascularization/classification , Choroidal Neovascularization/diagnosis , Wet Macular Degeneration/complications , Aged , Aged, 80 and over , Angiogenesis Inhibitors/therapeutic use , Choroid/blood supply , Choroidal Neovascularization/drug therapy , Choroidal Neovascularization/etiology , Ciliary Arteries/abnormalities , Ciliary Arteries/diagnostic imaging , Coloring Agents/administration & dosage , Female , Fluorescein Angiography , Humans , Indocyanine Green/administration & dosage , Intravitreal Injections , Male , Multimodal Imaging , Prospective Studies , Ranibizumab/therapeutic use , Tomography, Optical Coherence , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity/physiology , Wet Macular Degeneration/diagnosis , Wet Macular Degeneration/drug therapy
14.
Retina ; 40(8): 1634-1640, 2020 Aug.
Article in English | MEDLINE | ID: mdl-31800458

ABSTRACT

PURPOSE: To assess hyperreflective foci (HF) number and distribution in choroideremia (CHM) using spectral domain optical coherence tomography. METHODS: Observational, cross-sectional case series. Consecutive patients and matched controls (20 eyes each) underwent best-corrected visual acuity measurement, fundoscopy, blue-light autofluorescence (BL-FAF) and spectral domain optical coherence tomography. Hyperreflective foci were assessed on a horizontal spectral domain optical coherence tomography scan, in the 500-µm area centered on the umbo, and in the 500-µm-wide areas internal (preserved border) and external (pathologic border) to the chorioretinal atrophy of CHM patients, and in the parafovea of controls. Hyperreflective foci were subclassified as retinal or choroidal. The spared central islet was measured on BL-FAF. Primary outcome was HF quantification in CHM. Secondary outcomes included their relationships with atrophy extent. RESULTS: Choroideremia eyes disclosed a significantly higher HF number across the pathologic border and in the fovea when compared with controls; in particular, these HF were primarily located in the choroid (59-87%). Moreover, choroidal HF in the pathologic border inversely correlated with the area of the preserved central islet. CONCLUSION: Hyperreflective foci might turn out to be a potential biomarker of CHM activity or severity. In this regard, we hypothesize that HF may be related to macrophages activation or progressive retinal pigment epithelium degeneration.


Subject(s)
Biomarkers , Choroid/pathology , Choroideremia/diagnosis , Adaptor Proteins, Signal Transducing/genetics , Adult , Choroideremia/genetics , Choroideremia/physiopathology , Cross-Sectional Studies , Humans , Male , Middle Aged , Tomography, Optical Coherence , Visual Acuity/physiology
15.
J Biomech Eng ; 142(6)2020 06 01.
Article in English | MEDLINE | ID: mdl-31802106

ABSTRACT

We study the effects of surface tension and yield stress on mucus plug rupture. A three-dimensional simplified configuration is employed to simulate mucus plug rupture in a collapsed lung airway of the tenth generation. The Herschel-Bulkley model is used to take into account the non-Newtonian viscoplastic fluid properties of mucus. Results show that the maximum wall shear stress greatly changes right prior to the rupture of the mucus plug. The surface tension influences mainly the late stage of the rupture process when the plug deforms greatly and the curvature of the mucus-air interface becomes significant. High surface tension increases the wall shear stress and the time needed to rupture since it produces a resistance to the rupture, as well as strong stress and velocity gradients across the mucus-air interface. The yield stress effects are pronounced mainly at the beginning. High yield stress makes the plug take a long time to yield and slows down the whole rupture process. When the effects induced by the surface tension and yield forces are comparable, dynamical quantities strongly depend on the ratio of the two forces. The pressure difference (the only driving in the study) contributes to wall shear stress much more than yield stress and surface tension per unit length. Wall shear stress is less sensitive to the variation in yield stress than that in surface tension. In general, wall shear stress can be effectively reduced by the smaller pressure difference and surface tension.


Subject(s)
Stress, Mechanical , Blood Flow Velocity , Mucus , Pressure , Rheology , Surface Tension
16.
Chaos ; 30(7): 073121, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32752632

ABSTRACT

Steady three-dimensional flows in lid-driven cavities are investigated numerically using a high-order spectral-element solver for the incompressible Navier-Stokes equations. The focus is placed on critical points in the flow field, critical limit cycles, their heteroclinic connections, and on the existence, shape, and dependence on the Reynolds number of Kolmogorov-Arnold-Moser (KAM) tori. In finite-length cuboidal cavities at small Reynolds numbers, a thin layer of chaotic streamlines covers all walls. As the Reynolds number is increased, the chaotic layer widens and the complementary KAM tori shrink, eventually undergoing resonances, until they vanish. Accurate data for the location of closed streamlines and of KAM tori are provided, both of which reach very close to the moving lid. For steady periodic Taylor-Görtler vortices in spanwise infinitely extended cavities with a square cross section, chaotic streamlines occupy a large part of the flow domain immediately after the onset of Taylor-Görtler vortices. As the Reynolds number increases, the remaining KAM tori vanish from the Taylor-Görtler vortices, while KAM tori grow in the central region further away from the solid walls.

17.
Ophthalmology ; 131(4): e15-e16, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38206214
18.
Graefes Arch Clin Exp Ophthalmol ; 257(1): 41-48, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30374616

ABSTRACT

PURPOSE: To describe the hyperreflective foci (HF) characteristics in eyes affected by Stargardt disease (STGD), correlating HF with the atrophy progression at 1-year follow-up. METHODS: Prospective observational case series with 1-year follow-up. Twenty-eight eyes (14 patients) affected by STGD and 28 eyes (14 age- and sex-matched healthy patients) used as control group were recruited. All patients underwent a complete ophthalmologic examination including fundus autofluorescence and spectral-domain optical coherence tomography. The primary outcome was the identification of HF specific location in STGD and their modification over a 1-year follow-up. Secondary outcome included the correlation between the number and the location of HF and atrophic changes. RESULTS: HF turned out to be more frequent in STGD patients compared with healthy controls (p < 0.001). In particular, mean number of HF in the pathological edge was significantly higher than in the healthy edge of the atrophy (p < 0.001) and in the foveal area (p < 0.001). A negative correlation was found between the total HF number in the pathological edge and the atrophic area at baseline. HF number in the outer retina of the pathological edge significantly decreased between the baseline and the final follow-up examination (p = 0.011). The enlargement of the atrophic area in eyes with more than five outer retinal HF in the pathological edge at baseline was significantly less than that found in the eyes with fewer than five HF (p = 0.010). CONCLUSIONS: HF are most common at the pathological margin of the central atrophy, with outer retina foci being more frequently found in smaller atrophic lesions.


Subject(s)
Fluorescein Angiography/methods , Macular Degeneration/congenital , Retina/pathology , Tomography, Optical Coherence/methods , Visual Acuity , Adult , Aged , Disease Progression , Female , Follow-Up Studies , Fundus Oculi , Humans , Macular Degeneration/diagnosis , Male , Middle Aged , Prospective Studies , Stargardt Disease , Time Factors , Young Adult
19.
Graefes Arch Clin Exp Ophthalmol ; 257(2): 273-278, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30470876

ABSTRACT

PURPOSE: To evaluate the efficacy of intravitreal anti-VEGF injections in choroidal neovascularization (CNV) related to pattern dystrophy-like deposit in pseudoxanthoma elasticum (PXE). METHODS: One-year prospective, interventional study. Nine eyes were recruited in the ophthalmology departments of San Raffaele University and University of Barcelona. Each patient underwent best corrected visual acuity (BCVA) measurement on ETDRS chart, slit-lamp biomicroscopy, fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). The protocol included a first anti-VEGF injection, followed by monthly evaluations with re-treatments based on new funduscopic hemorrhages, fluid on OCT or leakage on FA and/or ICGA. Primary outcome measures were the mean BCVA changes. Secondary outcomes included central macular thickness (CMT) variations and the number of injections needed. RESULTS: At month 12, mean BCVA significantly improved from 20/45 to 20/35 Snellen equivalent, with 3 eyes gaining at least 3 ETDRS lines. Mean CMT decreased from 297 ± 22 to 262 ± 13 µm, after 5.5 ± 4.0 injections. No leakage was observed at the end of follow-up. CONCLUSIONS: Intravitreal anti-VEGF injections represent an effective treatment for CNV related to pattern dystrophy-like deposit in PXE, with an improvement of BCVA and CMT. Mean injection number is in line with other studies performed in CNV secondary to angioid streaks.


Subject(s)
Bevacizumab/administration & dosage , Choroidal Neovascularization/drug therapy , Pseudoxanthoma Elasticum/complications , Retinal Dystrophies/diagnosis , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity , Aged , Angiogenesis Inhibitors/administration & dosage , Choroidal Neovascularization/diagnosis , Choroidal Neovascularization/etiology , Female , Fluorescein Angiography/methods , Follow-Up Studies , Fundus Oculi , Humans , Intravitreal Injections , Male , Middle Aged , Prospective Studies , Pseudoxanthoma Elasticum/diagnosis , Pseudoxanthoma Elasticum/drug therapy , Retinal Dystrophies/complications , Retinal Dystrophies/drug therapy , Time Factors , Tomography, Optical Coherence/methods
20.
Retina ; 39(9): 1761-1767, 2019 Sep.
Article in English | MEDLINE | ID: mdl-29877903

ABSTRACT

PURPOSE: To assess foveal and parafoveal vasculature at the superficial capillary plexus, deep capillary plexus, and choriocapillaris of patients with X-linked retinoschisis by means of optical coherence tomography angiography. METHODS: Six patients with X-linked retinoschisis (12 eyes) and seven healthy controls (14 eyes) were recruited and underwent complete ophthalmologic examination, including best-corrected visual acuity, dilated fundoscopy, and 3 × 3-mm optical coherence tomography angiography macular scans (DRI OCT Triton; Topcon Corp). After segmentation and quality review, optical coherence tomography angiography slabs were imported into ImageJ 1.50 (NIH; Bethesda) and digitally binarized. Quantification of vessel density was performed after foveal avascular zone area measurement and exclusion. Patients were additionally divided into "responders" and "nonresponders" to dorzolamide therapy. RESULTS: Foveal avascular zone area resulted markedly enlarged at the deep capillary plexus (P < 0.001), particularly in nonresponders. Moreover, patients disclosed a significant deep capillary plexus rarefaction, when compared with controls (P: 0.04); however, a subanalysis revealed that this damage was limited to the fovea (P: 0.006). Finally, the enlargement of foveal avascular zone area positively correlated with a decline in best-corrected visual acuity (P: 0.01). CONCLUSION: Prominent foveal vascular impairment is detectable in the deep capillary plexus of patients with X-linked retinoschisis. Our results correlate with functional outcomes, suggesting a possible vascular role in X-linked retinoschisis clinical manifestations.


Subject(s)
Capillaries/pathology , Retinal Vessels/pathology , Retinoschisis/pathology , Adolescent , Capillaries/diagnostic imaging , Child , Child, Preschool , Cross-Sectional Studies , Fovea Centralis/diagnostic imaging , Fovea Centralis/pathology , Humans , Macular Degeneration/diagnostic imaging , Macular Degeneration/pathology , Male , Microvessels/diagnostic imaging , Microvessels/pathology , Prospective Studies , Retinal Vessels/diagnostic imaging , Retinoschisis/diagnostic imaging , Tomography, Optical Coherence
SELECTION OF CITATIONS
SEARCH DETAIL