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European Journal of Ophthalmology Jul 2021To report the individual retinal layer thickness in healthy subjects using wide-field optical coherence tomography.
PURPOSE
To report the individual retinal layer thickness in healthy subjects using wide-field optical coherence tomography.
METHODS
This was a prospective, cross-sectional study involving healthy subjects. A custom-designed semiautomated segmentation algorithm was used to split the retinal layers in seven bands, and individual retinal layer thicknesses were measured in horizontal (nasal, macular, and temporal segments) and vertical meridians (superior, macular, and inferior segments). The variation in retinal thickness was analyzed in different segments at an interval of 1 mm from reference points. Regression analysis was performed to identify the factors affecting retinal thickness.
RESULTS
Twenty eyes of 20 healthy subjects with mean age of 28.9 ± 6.3 years were analyzed. Overall, nasal and superior segments (mean ± standard deviation: 279.6 ± 17.0 and 234.4 ± 19.2 µm) had maximum and minimum retinal thicknesses, respectively. A total of seven bands were delineated in each optical coherence tomography b scan in each segment. Retinal nerve fiber layer was thickest immediately nasal to optic disk margin in horizontal scan (72.4 ± 32.4 µm) and near the vascular arcades in vertical meridian. Outer plexiform layer, external limiting membrane-ellipsoid zone and interdigitation zone-retinal pigment epithelium-Bruch's complex showed significant variation in both horizontal and vertical meridians (all p values <0.05). Macular segment in both meridians showed the highest coefficient of variation. Age was the only significant factor affecting retinal thickness in multiple regression analysis (p = 0.001).
CONCLUSIONS
Wide-field optical coherence tomography shows significant regional variation in overall and individual retinal layer thicknesses in macular and peripheral areas in healthy eyes with the highest variation in macular segment.
Topics: Cross-Sectional Studies; Humans; Infant, Newborn; Nerve Fibers; Prospective Studies; Retina; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 32476463
DOI: 10.1177/1120672120927664 -
BMC Ophthalmology Jun 2022Structural ophthalmologic findings have been reported in patients with β-thalassemia due to chronic anemia, iron overload, and iron chelation therapy toxicity in few...
BACKGROUND
Structural ophthalmologic findings have been reported in patients with β-thalassemia due to chronic anemia, iron overload, and iron chelation therapy toxicity in few previous studies. We aimed to investigate structural ocular findings and their relationship with hematological parameters in patients with transfusion-dependent β-thalassemia (TDT).
METHODS
In this cross-sectional study, from January 2018 to January 2019, 39 patients with TDT over the age of 18 participated. Multicolor fundus imaging, optical coherence tomography (OCT), and blue light fundus autofluorescence imaging were performed for all patients and 27 age- and sex-matched controls.
RESULTS
The mean age of patients was 28.6 ± 6.2 years. The central macular thickness and macular thicknesses in all quadrants were significantly thinner in patients than controls (P<0.05). None of the retinal nerve fiber layer (RNFL) measurements were significantly different between TDT patients and controls. There was a significantly negative correlation between hemoglobin with central macula thickness (r=-0.439, P=0.005). All measurements of macular subfield thickness were insignificantly thinner in patients with diabetes mellitus (DM) compared to the non-DM subgroup.
CONCLUSIONS
Macular thickness was significantly thinner in central macula and entire quadrants in TDT patients compared to healthy individuals; however, all RNFL measurement thicknesses were comparable between the two groups. Close monitoring of TDT patients by periodic ophthalmologic examinations with more focus on diabetic patients, patients with severe anemia and iron overload should be warranted.
Topics: Adult; Cross-Sectional Studies; Humans; Iron Overload; Macula Lutea; Middle Aged; Nerve Fibers; Retinal Ganglion Cells; Tomography, Optical Coherence; Young Adult; beta-Thalassemia
PubMed: 35751049
DOI: 10.1186/s12886-022-02490-z -
BioMed Research International 2022Recently, dentists can utilize three-dimensional printing technology in fabricating dental restoration. However, to date, there is a lack of evidence regarding the...
BACKGROUND
Recently, dentists can utilize three-dimensional printing technology in fabricating dental restoration. However, to date, there is a lack of evidence regarding the effect of printing layer thicknesses and postprinting on the mechanical properties of the 3D-printed temporary restorations with the additive manufacturing technique. So, this study evaluated the mechanical properties of a 3D-printed dental resin material with different printing layer thicknesses and postprinting methods.
METHODS
210 specimens of a temporary crown material (A2 EVERES TEMPORARY, SISMA, Italy) were 3D-printed with different printing layer thicknesses (25, 50, and 100 m). Then, specimens were 3D-printed using DLP technology (EVERES ZERO, DLP 3D printer, SISMA, Italy) which received seven different treatment conditions after printing: water storage for 24 h or 1 month, light curing or heat curing for 5 or 15 minutes, and control. Flexural properties were evaluated using a three-point bending test on a universal testing machine (ISO standard 4049). The Vickers hardness test was used to evaluate the microhardness of the material system. The degree of conversion was measured using an FT-IR ATR spectrophotometer. Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test ( ≤ 0.05).
RESULTS
The 100 m printing layer thickness had the highest flexural strength among the other thickness groups. As a combined effect printing thickness and postprinting conditions, the 100 m with the dry storage group has the highest flexural strength among the tested groups (94.60 MPa). Thus, the group with 100 m thickness that was heat cured for 5 minutes (HC 5 min 100 m) has the highest VHN value (VHN = 17.95). Also, the highest mean DC% was reported by 50 m layer thickness (42.84%).
CONCLUSIONS
The thickness of the 100 m printing layer had the highest flexural strength compared to the 25 m and 50 m groups. Also, the postprinting treatment conditions influenced the flexural strength and hardness of the 3D-printed resin material.
Topics: Flexural Strength; Hardness; Humans; Materials Testing; Printing, Three-Dimensional; Resins, Plant; Spectroscopy, Fourier Transform Infrared; Surface Properties
PubMed: 35237691
DOI: 10.1155/2022/8353137 -
International Ophthalmology Jan 2020The aim of the study was to evaluate the lamina cribrosa (LC) thickness, LC depth, and retinal nerve fiber layer (RNFL) thickness, in migraine patients with and without... (Observational Study)
Observational Study
PURPOSE
The aim of the study was to evaluate the lamina cribrosa (LC) thickness, LC depth, and retinal nerve fiber layer (RNFL) thickness, in migraine patients with and without aura, by using optical coherence tomography (OCT).
METHODS
This single-center, case-control study included 27 migraine with aura (Group I), 35 migraine patients without aura (Group II), and 35 healthy controls (Group III). In only the right eyes of participants, RNFL thickness in all quadrants was analyzed via OCT, whereas LC thickness and depth were measured by enhanced depth imaging OCT.
RESULTS
The mean age and sex distributions did not differ significantly across the groups (p = 0.460 and p = 0.941). The RNFL thickness was significantly lower in Group I (average and superotemporal, superonasal, and inferotemporal quadrants) and Group II (average and superotemporal and superonasal quadrants) when compared with Group III. Disease duration was significantly correlated with RNFL thickness on average and in all quadrants except in the superonasal quadrant in Groups I and II. Patients in Groups I and II had significantly thinner LC thicknesses and deeper LC depth than healthy participants in Group III.
CONCLUSIONS
The LC and RNFL thicknesses were thinner and the LC depth was deeper in migraine patients with or without aura than in healthy individuals, and disease duration correlated significantly with RNFL thickness. Both results suggest that migraine patients are at risk of developing glaucoma.
Topics: Adult; Cross-Sectional Studies; Eye Diseases; Female; Humans; Male; Migraine Disorders; Nerve Fibers; Optic Disk; Prospective Studies; Retinal Ganglion Cells; Risk Factors; Tomography, Optical Coherence
PubMed: 31432353
DOI: 10.1007/s10792-019-01160-2 -
International Journal of Ophthalmology 2021To develop a classifier for differentiating between healthy and early stage glaucoma eyes based on peripapillary retinal nerve fiber layer (RNFL) thicknesses measured...
AIM
To develop a classifier for differentiating between healthy and early stage glaucoma eyes based on peripapillary retinal nerve fiber layer (RNFL) thicknesses measured with optical coherence tomography (OCT), using machine learning algorithms with a high interpretability.
METHODS
Ninety patients with early glaucoma and 85 healthy eyes were included. Early glaucoma eyes showed a visual field (VF) defect with mean deviation >-6.00 dB and characteristic glaucomatous morphology. RNFL thickness in every quadrant, clock-hour and average thickness were used to feed machine learning algorithms. Cluster analysis was conducted to detect and exclude outliers. Tree gradient boosting algorithms were used to calculate the importance of parameters on the classifier and to check the relation between their values and its impact on the classifier. Parameters with the lowest importance were excluded and a weighted decision tree analysis was applied to obtain an interpretable classifier. Area under the ROC curve (AUC), accuracy and generalization ability of the model were estimated using cross validation techniques.
RESULTS
Average and 7 clock-hour RNFL thicknesses were the parameters with the highest importance. Correlation between parameter values and impact on classification displayed a stepped pattern for average thickness. Decision tree model revealed that average thickness lower than 82 µm was a high predictor for early glaucoma. Model scores had AUC of 0.953 (95%CI: 0.903-0998), with an accuracy of 89%.
CONCLUSION
Gradient boosting methods provide accurate and highly interpretable classifiers to discriminate between early glaucoma and healthy eyes. Average and 7-hour RNFL thicknesses have the best discriminant power.
PubMed: 33747815
DOI: 10.18240/ijo.2021.03.10 -
Frontiers in Medicine 2021To evaluate the effect of femtosecond laser-assisted keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness....
To evaluate the effect of femtosecond laser-assisted keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness. Thirty-seven eyes (37 patients) undergoing FS-LASIK were included in this prospective study. Optical coherence tomography (OCT) was performed 1 day before, 1 h and 1 day after FS-LASIK surgery. Eighteen male and nineteen females were enrolled. Mean patient age was 22.94 ± 4.22 years. One hour postoperatively, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, macula perifovea thickness, macula perifove volume, temporal RNFL thickness, and superior RNFL thickness measures showed significant decrease ( = 6.171, 6.032, and 9.837, 9.700, 2.532, 4.393, 4.926, 2.265; = 0.000, 0.000, 0.000, 0.000, 0.016, 0.000, 0.000, and 0.011). Day 1 post-operation, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, and inferior RNFL thickness measures showed significant change compared to preoperative measures ( = 3.620, 3.220, 2.901, 2.910, 3.632; = 0.001, 0.003, 0.006, 0.006, and 0.001). Our data suggest there are alterations in retinal foveal and RNFL measurements by OCT 1 h and 1 day after FS-LASIK surgery.
PubMed: 34912833
DOI: 10.3389/fmed.2021.778666 -
BMC Oral Health Feb 2023The aim of this study was to compare the pushout bond strength (POBS) of three hydraulic cements, when used at thicknesses of 3 and 5 mm.
BACKGROUND
The aim of this study was to compare the pushout bond strength (POBS) of three hydraulic cements, when used at thicknesses of 3 and 5 mm.
METHODS
78 root slices of 3 and 5 mm of thickness were obtained from human teeth. Cylindrical cavities of 1.4 mm of diameter were drilled and filled with Biodentine (BD), Totalfill Root Repair paste (TF) or ProRoot MTA White (PMTA). Pushout tests were performed 21 days later. The fracture pattern of each sample was also analyzed. POBS data were analyzed with Welch and Brown-Forsythe and Tamhane's post hoc tests and a Weibull analysis was also performed.
RESULTS
In the 3 mm group, TF showed significantly lower bond strength than BD and PMTA. In the 5 mm group, BD showed significantly higher bond strength than TF. Both BD and TF showed higher bond strength when the thickness of the sample increased, while PMTA did not.
CONCLUSIONS
TF and BD achieve higher pushout bond strength resistance when used at a thickness of 5 mm than at 3 mm, while the mean resistance of PMTA is less influenced by the thickness. At 5 mm of thickness, BD and PMTA exhibit similar resistance to displacement. However, the behavior of BD is more predictable than that of its predecessor. BD is a reliable hydraulic cement for clinical situations where thick cavities need to be filled and displacement resistance plays an important role. Clinicians need to consider choosing specific hydraulic cements according to the thickness of material to be used.
Topics: Humans; Calcium Compounds; Dental Cements; Dental Cementum; Silicates; Dental Bonding; Materials Testing
PubMed: 36750823
DOI: 10.1186/s12903-023-02758-w -
American Journal of Ophthalmology May 2024To evaluate the association between scleral thickness and a newly developed multimodal imaging-based classification of central serous chorioretinopathy (CSC).
PURPOSE
To evaluate the association between scleral thickness and a newly developed multimodal imaging-based classification of central serous chorioretinopathy (CSC).
DESIGN
Retrospective, cross-sectional study.
METHODS
This study included 217 eyes of 217 patients classified as simple or complex CSC based on the established protocols. Clinical and anatomical factors were compared between the 2 types. The scleral thickness was measured at 4 locations using anterior-segment optical coherence tomography.
RESULTS
Of the 217 eyes, 167 were classified as simple CSC and 50 as complex CSC. The complex CSC group showed older age (P = .011), higher male ratio (P = .001), more bilateral involvement (P < .001), poorer visual acuity (P < .001), greater subfoveal choroidal thickness (P = .025), and higher frequency of loculation of fluid (P < .001) and ciliochoroidal effusion (P < .001) than the simple CSC group. The complex CSC group had significantly greater scleral thicknesses in the superior, temporal, inferior, and nasal directions (all P < .001) than the simple CSC group. Multivariable analysis revealed that older age (odds ratio [OR] 1.054, 95% confidence interval [CI] 1.013-1.097, P < .001), male sex (OR 10.445, 95% CI 1.151-94.778, P < .001), bilateral involvement (OR 7.641, 95% CI 3.316-17.607, P < .001), and the mean value of scleral thicknesses in 4 directions (OR 1.022, 95% CI 1.012-1.032, P < .001) were significantly associated with the complex CSC.
CONCLUSIONS
Older age, male sex, bilateral involvement, and thick sclera were associated with the complex CSC. Scleral thickness seemed to determine the clinical manifestations of CSC.
Topics: Humans; Male; Retrospective Studies; Central Serous Chorioretinopathy; Sclera; Cross-Sectional Studies; Fluorescein Angiography; Visual Acuity; Choroid; Tomography, Optical Coherence
PubMed: 38281567
DOI: 10.1016/j.ajo.2024.01.025 -
Frontiers in Physiology 2020Track cyclists are required to perform short- and long-term efforts during sprint and endurance race events, respectively. The 200 m flying sprint races require maximal...
Track cyclists are required to perform short- and long-term efforts during sprint and endurance race events, respectively. The 200 m flying sprint races require maximal power output and anaerobic capacity, while the 4,000 m pursuit cyclists demand a high level of aerobic capacity. Our goal was to investigate spatial changes in morphological and mechanical properties displayed using 3D topographical maps of the quadriceps muscle and tendons after 200 m flying start and 4,000 m individual pursuit race in elite track cyclists. We hypothesized a non-uniform distribution of the changes in the quadriceps muscle stiffness (QM), and acute alterations in quadriceps tendon (QT) and patellar tendon (PT) thickness. Fifteen men elite sprint and 15 elite men endurance track cyclists participated. Sprint track cyclists participated in a 200 m flying start, while endurance track cyclists in 4,000 m individual pursuit. Outcomes including QT (5-10-15 mm proximal to the upper edge of the patella), PT (5-10-15-20 mm inferior to the apex of the patella)-using ultrasonography evaluation, QM, and quadriceps tendon stiffness (QT) were measured according to anatomically defined locations (point 1-8) and patellar tendon stiffness (PT)-using myotonometry, measured in a midway point between the patella distal and the tuberosity of tibial. All parameters were assessed before and after (up to 5 min) the 200 m or 4,000 m events. Sprint track cyclists had significantly larger QT and PT than endurance track cyclists. analysis showed significant spatial differences in QM between rectus femoris, vastus lateralis, and vastus medialis in sprint track cyclists. At before race, sprint track cyclists presented significantly higher mean QT and PT, and higher QM and the QT, as compared with the endurance track cyclists. The observed changes in PT and QT were mostly related to adaptation-based vascularity and hypertrophy processes. The current study suggests that assessments using both ultrasonography and myotonometry provides crucial information about tendons and muscles properties and their acute adaptation to exercise. Higher stiffness in sprint compared with endurance track cyclists at baseline seems to highlight alterations in mechanical properties of the tendon and muscle that could lead to overuse injuries.
PubMed: 33381054
DOI: 10.3389/fphys.2020.607208 -
American Journal of Ophthalmology Mar 2022To elucidate clinical factors related to the presence of loculation of fluid (LOF) in the posterior choroid in central serous chorioretinopathy (CSC).
PURPOSE
To elucidate clinical factors related to the presence of loculation of fluid (LOF) in the posterior choroid in central serous chorioretinopathy (CSC).
DESIGN
Retrospective, cross-sectional study.
METHODS
This single-center study included 158 eyes from 158 patients with CSC who were classified into LOF and non-LOF groups. The groups were compared for age, sex, spherical equivalent, axial length, subfoveal choroidal thickness (SCT), and scleral thickness. Using swept-source optical coherence tomography (OCT), we determined the presence of LOF based on B-scan and en face images. Scleral thickness was measured 6 mm posterior to the scleral spur in 4 directions using anterior-segment OCT.
RESULTS
The 158 eyes were classified into 98 eyes in the LOF group and 60 eyes in the non-LOF group. In univariable analyses, the LOF group was younger (P = .01) and had a higher male ratio (P = .03) and greater SCT (P < .001) than the non-LOF group. All scleral thicknesses at the superior, temporal, inferior, and nasal points were greater in the LOF group than in the non-LOF group (426.2 vs 395.1 μm, 445.7 vs 414.9 μm, 459.2 vs 428.8 μm, 445.4 vs 414.3 μm, all P < .05). Multivariable analyses found that SCT (odds ratio [OR] 1.02, 95% CI 1.01-1.02, P < .001) and mean scleral thickness (OR 1.02, 95% CI 1.02-1.03, P = .002) were significantly associated with the presence of LOF.
CONCLUSION
A thick choroid and thick sclera appeared to be related to the presence of LOF in CSC.
Topics: Central Serous Chorioretinopathy; Choroid; Cross-Sectional Studies; Fluorescein Angiography; Humans; Male; Retrospective Studies; Tomography, Optical Coherence
PubMed: 34547278
DOI: 10.1016/j.ajo.2021.09.009