Search Results (517)

Biofilm formation on denture base materials may contribute to oral diseases such as denture stomatitis and therefore represents an important factor in prosthodontic treatment. This in vitro study investigated biofilm formation on dental prosthetic materials manufactured by additive, subtractive, and conventional techniques. Disc-shaped specimens were fabricated from 3D-printed Denture Base Resin (Formlabs), milled Lucitone Digital Fit (Dentsply Sirona), and conventionally processed cold-polymerized PALAPress (Kulzer). Biofilm formation by Streptococcus mutans and Streptococcus sanguinis was assessed separately over a 21-day incubation period using crystal violet staining and photometric determination of optical density at eight predefined time points. Surface characteristics before and after microbial colonization were qualitatively evaluated by scanning electron microscopy. For S. mutans, significant material-dependent differences were observed only at selected time points, while overall biofilm accumulation remained low. In contrast, S. sanguinis exhibited pronounced and repeated differences, with milled PMMA generally showing lower biofilm accumulation compared with additively manufactured and conventionally processed materials. Overall, S. sanguinis formed significantly more biofilm than S. mutans across all materials and time points. These findings indicate that both manufacturing technique and bacterial species influence biofilm formation on denture base materials. Full article

Background and Objectives: Optic disc drusen (ODD) are deposits in the optic nerve head that can look like true swelling, and in some patients, slowly damage the optic nerve and cause visual field loss. We aimed to identify which eyes are most likely to worsen over time using common clinic tests. Methods: We studied 131 adults with OCT-confirmed ODD who also had OCT-angiography (a scan that measures small blood vessels around the optic nerve) and repeated visual field tests over at least 18 months. We measured (1) the size of the drusen (maximum drusen height), (2) blood vessel density around and inside the optic nerve, and (3) change in visual field performance over time. “Fast progression” was defined as visual field worsening of ≥0.5 dB per year. Results: Eyes with superficial ODD had larger drusen than buried ODD (382.6 ± 110.9 vs. 247.2 ± 92.8 µm; p < 0.001) and more frequent visual field defects (78.6% vs. 58.7%; p = 0.02). When blood vessel density around the optic nerve was low, fast progression was much more common (52.3%) than in the middle (16.3%) or highest groups (13.6%; p < 0.001). In the adjusted model, fast progression was more likely with superficial ODD (OR 6.3) and larger drusen (OR 2.0 per 100 µm), and less likely when the vessel density was higher (OR 0.8 per 1% increase). Adding the vessel measurements improved the prediction accuracy (AUC 0.8 → 0.9; p = 0.011). Conclusions: Combining drusen size and blood vessel measurements helps identify ODD patients at higher risk of faster visual field loss and may guide closer follow-up. Full article

Glaucoma affects a significant proportion of people worldwide, and if it progresses to a severe stage, it can lead to blindness. Furthermore, screening and accurately diagnosing glaucoma present a challenge for ophthalmologists. Early detection of glaucoma is crucial because it allows for timely treatment, potentially preventing severe complications that could lead to blindness. Typically, ophthalmologists diagnose glaucoma by analyzing eye fundus photographs to assess the ratio of the optic cup and optic disc (CDR). Machine learning algorithms can assist in glaucoma detection by classifying fundus images. This study introduces image preprocessing techniques for optic disc localization, combined with an integrating multi-view network for accurate glaucoma classification. The dataset used in this research was obtained from Naresuan University Hospital. The study found that EfficientNet underwent training using the Adam optimizer at a fixed learning rate of 0.0001. The multi-view network achieved Accuracy 90.48%, AUC 95.14%, Precision 81.95%, Recall 75.90%, and F1-score 78.72%. This study presents an effective approach to assist ophthalmologists in detecting early-stage glaucoma and glaucoma, thereby improving diagnostic efficiency. Full article

High myopia is increasingly prevalent and complicates glaucoma diagnosis. Axial elongation remodels the optic nerve head (ONH) and parapapillary tissues, producing structural and functional changes that mimic glaucoma—termed myopic optic neuropathy (MON). We reviewed current concepts on the MON–glaucomatous optic neuropathy (GON) spectrum and practical implications for diagnosis, monitoring, and management. A focused PubMed search targeted high/pathologic myopia, glaucoma, ONH and parapapillary anatomy, optical coherence tomography (OCT)/OCT angiography, visual fields, and progression. Major reviews, population-based studies, and longitudinal investigations were prioritized and integrated into a clinician-oriented framework. Greater myopia severity is associated with higher glaucoma risk and, in some cohorts, greater treatment burden, including surgery. Disc tilt, torsion, parapapillary atrophy, and staphyloma-related curvature complicate structural assessment and reduce reliability of single-visit OCT due to magnification and segmentation artifacts. Visual fields may be atypical, and central defects are under-sampled by standard 24-2 testing. Progression-centered strategies—combining event- and trend-based analyses and confirmation rules—distinguish MON-predominant changes from true GON or overlap and guide follow-up. In highly myopic eyes, multimodal structure–function assessment anchored on reproducible progression enhances diagnostic confidence and guides individualized intraocular pressure–lowering therapy. Standardized reporting of myopia definitions and progression criteria is recommended. Full article

Background/Objectives: To characterize sectoral corneal thickness (CT) profiles in eyes with primary open-angle glaucoma (POAG) compared with healthy eyes and to evaluate potential associations between CT, retinal nerve fiber layer (RNFL) thickness, and optic disc rim area (RA). Methods: In this cross-sectional study, 192 participants (91 with POAG and 101 controls) contributed 297 eyes (145 glaucoma eyes and 152 control eyes). All participants underwent comprehensive ophthalmological examination and spectral-domain optical coherence tomography (OCT; Optovue Solix, Fremont, CA, USA) to obtain peripapillary RNFL measurements, optic disc rim area, and corneal pachymetry maps across five sectors (central, superior, inferior, temporal, and nasal). Repeated-measures correlation analyses were used to assess within-subject associations between CT and RA, and generalized estimating equation (GEE) models were applied to evaluate independent associations between CT, glaucoma status, disease severity, and RNFL thickness while adjusting for relevant covariates. Results: Eyes with POAG exhibited significantly thinner corneas across all sectors compared with controls (all p < 0.05), with the greatest differences observed in the superior (median 607.0 μm vs. 640.0 μm, p < 0.001) and temporal (562.0 μm vs. 579.5 μm, p < 0.001) regions. Average RNFL thickness and rim area were also significantly reduced in glaucoma eyes (all p < 0.001). However, no independent associations between sectoral CT and RNFL thickness or RA were observed after adjustment for multiple comparisons. Although nominal associations between thinner inferotemporal CT and reduced RNFL thickness were observed in unadjusted analyses, these did not remain statistically significant after false discovery rate correction. In multivariable GEE models, glaucoma diagnosis and greater disease severity were consistently associated with reduced RNFL thickness (β range: −11.0 to −42.2 μm; all p < 0.001), whereas CT was not independently associated with RNFL thickness (all adjusted p > 0.07). Conclusions: Sectoral corneal thickness is significantly reduced in eyes with POAG but does not independently correlate with RNFL thickness or optic disc rim area after adjustment for confounding factors. These findings support the concept that corneal thinning reflects structural and biomechanical susceptibility to glaucoma rather than serving as a marker of established neuroretinal damage severity. Further longitudinal studies incorporating comprehensive biomechanical assessments are warranted to clarify the role of corneal structure in glaucoma pathophysiology. Full article

Background: The aim of this study was to evaluate the influence of demographic, clinical and physical factors on the occurrence of ocular complications after ruthenium-106 (Ru-106) brachytherapy, iodine-125 (I-125) brachytherapy and proton therapy of uveal melanoma. Methods: A retrospective analysis of 300 patients’ electronic and paper medical records treated for uveal melanoma at the Department of Ophthalmology and Ocular Oncology, University Hospital in Krakow, Poland, from May 2014 to December 2016 was performed. The created database, which includes numerous parameters characterizing patients, tumors, applied treatments and their effects, with particular emphasis on the occurrence of ocular complications, was subjected to detailed analysis. The influence of selected factors on the occurrence of identified complications was checked by performing a univariable Cox proportional hazards regression analysis, and then the factors that were statistically significant were included in a multivariable Cox proportional hazards regression analysis which gave the final results. Results: Of the 300 patients, 125 (41.67%) were treated with Ru-106 brachytherapy (87 (29%) with CCB plaque and 38 (12.67%) with COB plaque), 102 (34%) with I-125 brachytherapy and 73 (24.33%) with proton therapy. Mean follow-up was 88.63 months (median 89, range: 20–127). The occurrence of cataract was associated with the older age of patients. Maculopathy was associated with female sex, younger age, use of I-125 brachytherapy, tumor location involving the macula and/or optic disc and moderate tumor pigmentation. Diagnosis of systemic hypertension was associated with a lower risk of maculopathy. Retinopathy was associated with younger age, tumor location involving the macula and/or optic disc and the use of I-125 brachytherapy. Optic neuropathy was associated with younger age, greater tumor largest base diameter, tumor location involving the macula and/or optic disc and the use of I-125 brachytherapy. Secondary glaucoma was associated with baseline best corrected visual acuity (BCVA) weaker than 0.5, greater tumor thickness, involvement of the left eye and the use of I-125 brachytherapy. Vitreous hemorrhage was associated with greater tumor thickness, tumor location including the macula and/or optic disc and mushroom-shaped tumor. Conclusions: Our study demonstrated an association between demographic, clinical, and physical factors and the occurrence of ocular complications after radiotherapy for uveal melanoma. Full article

Background: Multiple evanescent white dot syndrome (MEWDS) is usually acute and self-limited, whereas multifocal choroiditis (MFC)/punctate inner choroidopathy (PIC) is relapsing; overlap can obscure early diagnosis and requires longitudinal multimodal imaging. Methods: We report a 4-year follow-up of a 31-year-old woman with fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (SD-OCT), plus a systemic/neurologic/rheumatologic work-up. Treatment included intravenous methylprednisolone for presumed optic neuritis, followed by topical, periocular, intravitreal, and systemic corticosteroids, later escalated to adalimumab and an intravitreal dexamethasone implant. Because foveal granularity could not be documented, baseline was termed “MEWDS-like”. Diagnostic labelling was benchmarked against Standardization of Uveitis Nomenclature (SUN) criteria, and choroidal neovascularization (CNV) was assessed at each relapse by OCT and FA. Results: The right eye initially showed a MEWDS-like pattern with wreath-like FA lesions and disc leakage, hyperautofluorescent FAF lesions, focal ellipsoid zone disruption on SD-OCT, and multifocal ICGA hypofluorescent spots. A relapse at 6 months with peripapillary inflammatory foci and recurrent cystoid macular edema supported reclassification to a unilateral MFC/PIC-spectrum phenotype. At 2 years, the fellow eye developed mild vitritis, peripapillary hyperautofluorescence, peripapillary/arcade leakage on FA, delayed peripapillary filling on ICGA, and cystoid macular edema, establishing sequential bilateral MFC; no CNV developed and anti-vascular endothelial growth factor (anti-VEGF) therapy was not required. Complications included steroid-induced ocular hypertension and cataract surgery. Conclusions: The purpose of this report is to highlight longitudinal imaging “red flags” that supported reclassification from a MEWDS-like phenotype to a sequential bilateral MFC/PIC-spectrum disease. Full article

Eye diseases, such as glaucoma, diabetic retinopathy, and age-related macular degeneration, drive the growing need for reliable and scalable analyses of fundus and optical coherence tomography (OCT) images. Deep learning performs strongly in ocular structure segmentation. However, it typically relies on dense pixel-wise annotations, which are costly and difficult to obtain at scale. Weakly supervised learning (WSL) can reduce this burden by leveraging coarse labels, limited strong annotations, and unlabeled data. This systematic umbrella review synthesizes survey and review articles on weakly supervised deep learning for image segmentation, with a focus on ocular imaging (fundus and OCT/OCTA). After analyzing twenty-one secondary studies, the main finding reveals an “empty intersection”: WSL-focused segmentation surveys are often modality-agnostic. Conversely, ocular reviews are predominantly fully supervised and seldom offer quantitative evidence on annotation-effort savings or direct comparisons between weak and fully supervised methods on identical datasets. Across the included reviews, label-efficient strategies cluster around CAM/MIL formulations, sparse supervision (points/scribbles/boxes), pseudo-labelling/self-training, and semi-/self-supervised learning, implemented mainly with U-Net/DeepLab families and increasingly Transformer or hybrid backbones. These results provide a structured map of available WSL mechanisms and, critically, identify reproducible reporting gaps that currently prevent fair benchmarking in ocular segmentation. Therefore, this review supports the development of ocular-specific benchmarks and minimum reporting practices that link segmentation performance to annotation effort. Full article

Recent developments in all-ceramic restorative materials have enhanced the clinical applicability of lithium disilicate for aesthetic dental restorations. The current study explores the influence of sintering parameter modulation over the translucency and color change of Amber Mill and IPS e.max CAD ceramics at baseline and following simulated aging through thermocycling and simulated toothbrushing. Sixty discs of lithium disilicate were assigned to two groups according to material type (Amber Mill; E-max), then according to translucency level (HT: high translucency; LT: low translucency). All specimens were sintered, polished, and ultrasonically cleaned in accordance with manufacturer guidelines. Optical properties—including translucency parameter (TP), color difference (ΔE), and color coordinates (L*, a*, b*)—were measured using a spectrophotometer at baseline and after a five-year clinical simulation. Scanning electron microscope (SEM) analysis was performed. Amber Mill-HT demonstrated the highest initial translucency (15.48 ± 0.89), followed by Amber Mill-LT (12.52 ± 0.61). Aging increased TP values in Amber Mill groups, while a slight reduction was observed in E-max groups. Amber Mill-LT exhibited the lowest color change (ΔE = 0.80 ± 0.10), reflecting superior color stability, whereas E-max-LT showed the highest ΔE (1.43 ± 0.21). SEM analysis demonstrated distinct microstructural differences between materials and translucency levels. High-translucency ceramics exhibited finer, more uniform lithium disilicate crystals and continuous glassy matrices, whereas low-translucency groups showed larger crystals, increased heterogeneity, and greater surface irregularities after aging. Overall, Amber Mill-LT displayed the greatest color stability, whereas E-max groupsretained translucency more consistently. All evaluated ceramics showed optical alterations within clinically acceptable limits, confirming their suitability for aesthetic restorative applications. Full article

Background/Objectives: Multiple sclerosis (MS)-related optic neuritis (ON) results in thinning of the peripapillary nerve fiber layer (pRNFL) which tends to be temporal quadrant-predominant. Optical coherence tomography angiography (OCTA) enables visualization of the retinal vasculature. Prior studies have shown reduced peripapillary vessel density (VD) in MS but data on the quadrantic pattern of peripapillary VD loss are limited. Our objective was to investigate the pattern of OCTA-derived peripapillary VD reduction in MS. Methods: People with MS (PwMS) and healthy controls (HC) underwent optic disc OCTA scans (Solix, Optovue) and VD was derived for the peripapillary region and quadrants. Eyes with ON within six months were excluded. Analyses were performed with generalized estimating equations models and standardized coefficients are presented. Results: We included 50 eyes from 29 PwMS (12 ON, 38 non-ON) and 12 eyes from 6 HC. VD in the peripapillary region was lower in MS ON eyes compared to HC with the largest effect size observed in the temporal quadrant (average: −1.47, p < 0.001; superior: −1.08, p = 0.006; inferior: −0.94; p = 0.017; temporal: −1.55; p < 0.001; nasal: −1.06, p = 0.007). In MS non-ON eyes, only temporal VD was significantly lower compared to HC eyes (temporal: −0.77, p = 0.004). Moderate to strong correlations were observed between OCT and corresponding OCTA metrics from the same regions. Conclusions: Our findings suggest that vascular alterations in the peripapillary region may exhibit a temporal quadrant predominant pattern. Larger studies are needed to further characterize the patterns and temporal evolution of retinal peripapillary vascular injury in MS. Full article

Commercial optical discs are used as low-cost grating substrates for fabricating grating-coupled surface plasmon resonance (GC-SPR) sensors, and the effects of front-side and back-side illumination are systematically compared. Three different discs were used as grating substrates with grating periods (Λ) of 322 ± 5.2 nm for BD-R, 805 ± 7.5 nm for DVD-R, and 1.582 ± 0.013 µm for CD-R. Silver (Ag) and copper (Cu) films were deposited by magnetron sputtering to form plasmonic gratings. The shallow grating height of BD-R supported continuous metal coverage, while the deeper DVD-R and CD-R grooves resulted in a less continuous layer. Plasmonic responses were measured using wavelength-modulated SPR spectroscopy and predicted with rigorous coupled wave analysis (RCWA). Ag-coated gratings produced sharper and more clearly identifiable resonances than Cu-coated gratings, which exhibited broader due to stronger damping. Front-side illumination produced stronger and more reproducible SPR excitation across all disc types, whereas back-side illumination resulted in more complex spectra as light propagates through the polycarbonate layer. Refractive index sensitivities based using Ag-coated discs of 394, 321, and 290 nm/RIU were obtained for CD-R, BD-R, and DVD-R, respectively. The results clarify the influence of fabrication strategy, illumination geometry, and disc grating geometry on resonance quality and sensitivity in low-cost optical disc-based GC-SPR sensors. Full article

The Indian Diabetic Retinopathy Image Dataset (IDRiD) has been widely adopted for DR lesion segmentation research. However, it contains annotation gaps for proliferative DR lesions and labeling errors that limit its utility for comprehensive automated screening systems. We present Refined IDRiD, an enhanced version that addresses these limitations through (1) expert ophthalmologist validation and correction of labeling errors in original annotations for four non-proliferative lesions (microaneurysms, hemorrhages, hard exudates, cotton-wool spots), (2) the addition of three critical proliferative DR lesion annotations (neovascularization, vitreous hemorrhage, intraretinal microvascular abnormalities), and (3) the integration of comprehensive anatomical context (optic disc, fovea, blood vessels, retinal region). A team of three ophthalmologists (one senior specialist with >10 years’ experience, two expert fundus image annotators) conducted systematic annotation refinement, achieving an inter-rater agreement F1-score of 0.9012. The enhanced dataset comprises 81 high-resolution fundus images with pixel-level annotations for seven DR lesion types and four anatomical structures. All images were cropped to the retinal region of interest and resized to 1024 × 1024 pixels, with annotations stored as unified grayscale masks containing 12 classes enabling efficient multi-task learning. Refined IDRiD enables training of comprehensive DR screening systems capable of detecting both non-proliferative and proliferative stages while reducing false positives through anatomical context awareness. Full article

This in vitro study aimed to evaluate color recovery after 7 and 15 days of brushing with six whitening toothpastes that have different whitening mechanisms on coffee-stained anterior microhybrid composite resin. It also investigated the effects of brushing on surface microhardness. Disc-shaped specimens (2 mm thick, 10 mm in diameter) were prepared from a microhybrid anterior composite resin (GC G-ænial Anterior) (n = 10) and immersed in a coffee solution for 5 days to induce discoloration. Afterwards, the specimens underwent brushing simulation for 7 and 15 days using six whitening toothpastes and a non-whitening control toothpaste (Sensodyne Pronamel). Color changes were measured using a spectrophotometer based on the CIEDE2000 system, and surface microhardness was assessed with a Vickers microhardness tester. Statistical analysis was performed using repeated-measures analysis of variance (ANOVA). After coffee staining, all specimens showed discoloration exceeding the clinical acceptability threshold (ΔE₀₀ > 1.8). After 7 days of brushing, significantly greater color recovery was observed in the Signal Whitening System, Colgate Optic White, and Sensodyne Extra Whitening groups compared to other toothpaste groups (p < 0.05). By the end of the 15-day brushing period, all whitening toothpastes resulted in visually and clinically significant reductions in coffee-induced discoloration (ΔE₀₀ > 1.8), with the highest color recovery noted in the Signal Whitening System group (ΔE₀₀ = 2.52 ± 0.91). Regarding surface microhardness, significant increases were observed in all groups after brushing (p < 0.05). The Pronamel, Colgate Optic White, and Advance groups demonstrated significantly higher Vickers microhardness values compared to the Rocs group at the end of the 15-day period (p < 0.05). Full article

Objective: To clarify the pathophysiology of myopic optic neuropathy (MON) and its relationship to glaucomatous optic neuropathy (GON). Background: MON is presumed to be associated with posterior pole ectasia and deformation of the lamina cribrosa (LC) and parapapillary region. Its dependance on intraocular pressure is expected to be weaker than that of GON; however, the characteristics and clinical behavior of MON remain incompletely understood. Methods: A PubMed search using the keywords myopia, glaucoma, retinal nerve fiber, optic disc, and axonal transport identified 234 relevant publications, which were analyzed in this narrative review. Results: In myopic eyes, a large optic disc, thin or defective LC, and parapapillary microvasculature dropout (pMvD) are considered signs of increased vulnerability to glaucomatous injury. Despite these structural risk factors, visual field (VF) progression in myopic patients with glaucoma is often slow. The involvement of MON, which likely develops in young adulthood and stabilizes with aging, may explain this discrepancy. MON may substantially contribute to the development of central VF defects in myopic glaucoma, which are associated with elongation of papillomacular bundle, pMvD, and normal tension glaucoma. Experimental studies demonstrating impaired axonal transport at the optic disc margin provide important insights into the pathogenesis of MON. Additionally, optic disc deformations in myopia including disc tilting, rotation, and focal thinning or defects of the LC may contribute to atypical VF defects and altered susceptibility to glaucomatous damage. Conclusions: Interaction between MON and GON may explain atypical VF defects and the relatively slow VF progression observed in myopic patients with glaucoma-like VF defects. Full article

Background/Objectives: Optical coherence tomography angiography (OCTA) is a non-invasive imaging method that enables accurate in vivo visualisation and quantification of the macular and optic nerve head microvasculature, providing an indirect assessment of local retinal perfusion. This study aimed to evaluate the changes in OCTA perfusion parameters of macula and optic nerve head in healthy individuals following different isometric exercises and to determine their association with intraocular pressure alterations. Methods: Each subject performed four isometric exercises: elbow plank, reverse plank, right-side plank, and wall sit. Measurements of intraocular pressure, systemic blood pressure, heart rate, and OCT angiography of macula and optic nerve head were conducted before each exercise, immediately after its completion, and after a five-minute rest period. Intraocular pressure was measured using a Perkins applanation tonometer, and systemic blood pressure and heart rate were recorded using an automated sphygmomanometer. The relationship between changes in intraocular pressure and OCTA perfusion parameters was analysed. Results: A total of 12 eyes of 12 healthy subjects were included in the study, with a mean age of 28.67 ± 2.39 years. An immediate reduction in optic nerve head vessel density was observed after each exercise (elbow plank: p = 0.012; wall sit: p = 0.009; reverse plank: p < 0.001; right-side plank: p < 0.001), with a sustained decrease during the rest period following right-side plank. No significant changes in vessel density were observed in the macular region. Heart rate and systemic blood pressure increased after each exercise, while intraocular pressure increased following all exercises except the wall sit. Changes in intraocular pressure were significantly negatively associated with changes in optic nerve head vessel density in the post-rest period following elbow plank (inside disc sector: b = −1.153, p = 0.02, peripapillary sector: b = −0.369, p = 0.009) and reverse plank (whole image sector: b = −0.589, p = 0.031). Conclusions: The performance of isometric exercises induced an acute reduction in optic nerve head vessel density, and a significant association with intraocular pressure changes was observed. OCTA represents a promising research tool not only for the assessment of retinal microcirculation but also in the field of sports medicine. Full article