Search Results (631)

Background: Trabeculectomy is the standard surgical treatment for advanced glaucoma, yet the relationship between postoperative intraocular pressure (IOP) and long-term structural preservation remains unclear. We investigated longitudinal changes in peripapillary retinal nerve fiber layer (RNFL) thickness following trabeculectomy in primary open-angle glaucoma and evaluated whether lower postoperative IOP levels are associated with improved structural stability. Methods: This retrospective consecutive case series included 106 eyes undergoing trabeculectomy between 2010 and 2020 with follow-up of up to 5 years. RNFL thickness was assessed using spectral-domain optical coherence tomography at baseline and during follow-up. IOP, glaucoma medication use, best-corrected visual acuity, and visual field mean defect were recorded longitudinally. Results: Mean IOP decreased from 23.8 ± 0.9 mmHg preoperatively to 10.5 ± 0.7 mmHg at 1 month and remained significantly reduced at 5 years (13.8 ± 0.7 mmHg), with sustained reduction in medication use. RNFL thickness declined significantly from 64.4 ± 2.0 µm during the first postoperative year to 57.2 ± 1.6 µm and subsequently remained relatively stable. While eyes achieving a postoperative IOP <12 mmHg showed no statistically significant RNFL thinning compared to baseline, eyes with higher postoperative IOP exhibited greater structural decline despite meeting conventional success criteria. Conclusions: Trabeculectomy provides durable IOP reduction; however, early structural loss may still occur. Our findings suggest that lower postoperative IOP levels may be associated with greater structural preservation, although this relationship requires further investigation. Full article

Background: The rabbit (Oryctolagus cuniculus) is a currently indispensable pre-clinical model for fundamental discovery and translational research in glaucoma surgery. While not fully representative of the human eye, the rabbit often serves as the site of the first robust assessment of a new chemical entity in an anatomically and physiologically relevant setting. In later stages of development, the rabbit is also a critical model for regulatory-facing Good Laboratory Practice (GLP)-graded pre-clinical safety studies. However, while guidelines exist for human glaucoma surgeries in terms of patient profile vs. surgery type and success criteria, there is limited collated information available on how rabbit glaucoma filtration surgeries are designed, use and mode of administration of anti-metabolite Mitomycin-C (MMC) and post-operative antibiotic and anti-inflammatory dosing regimes. These disparities limit cross-comparability in studies and encourage sub-optimal study design and incomplete reporting. Methods: This review investigated and collated current procedural and reporting practices based on 100 peer-reviewed rabbit glaucoma filtration surgery publications from the years 2011–2025. Publications meeting acceptance criteria were segmented into pre-operative designs (ethical approval, rabbit characteristics, study duration), intra-operative (surgery type, surgical approach, use of MMC) and post-operative follow-up (antibiotics, anti-inflammatories, analysis and adverse events). Results: It was found that there were clear preferences in animal model selection, study design and intra-/post-operative anti-fibrotic/inflammatory treatment regimes. Additionally, there were several areas identified where reporting was ambiguous or omitted, e.g., rabbit age, post-operative treatments, adverse events. The levels of omission were 16–30% and represent areas for improvement and highlight the need for ongoing review in pre-clinical research. Full article

Retinitis pigmentosa (RP) is a rare inherited retinal disorder in which fundus changes may be subtle and heterogeneous, limiting detection from color fundus images. This study evaluated multiple machine learning architectures for binary-RP versus healthy-control classification, and developed a reproducible pipeline for research-oriented screening support. Three publicly available fundus datasets were combined, including 248 RP images and 1045 healthy controls. An 80/20 train–test split was used, with targeted data augmentation applied only to RP images in the training set to address class imbalance. ConvNeXt-Tiny, ResNet101V2, EfficientNet-B0, a baseline classifier, and custom shallow convolutional neural networks were compared using accuracy, precision, recall, F1-score, confusion matrices, and ROC/precision–recall analyses. A compact ShallowCNN provided the best sensitivity–performance trade-off. On the fixed image-level test set, Adam with a learning rate of 0.0005 reached 96.51% accuracy, while SGD with a learning rate of 0.001 achieved 98% RP recall, minimizing false negatives. The trained models were exported to ONNX and integrated into a Windows inference tool. The proposed framework provides an open, reproducible benchmark for technical evaluation, although external validation is required before clinical use. Full article

Nd laser posterior capsulotomy is the standard treatment for posterior capsule opacification following cataract surgery. Although generally considered safe, inadvertent laser impacts on the intraocular lens (IOL) optic may induce permanent surface defects that contribute to postoperative dysphotopsias and reduced visual quality. This experimental study investigated the optical consequences of Nd laser-induced damage on two commercially available hydrophobic acrylic IOLs, focusing on retinal light distribution and optical image quality. Two hydrophobic acrylic monofocal IOL models, the CT LUCIA (Carl Zeiss Meditec) and the AcrySof IQ (Alcon), were mounted on a customized experimental holder and exposed to standardized Nd laser applications consisting of 5, 10, or 15 laser shots. Laser interactions were documented using the PhysioGo.Lite laser platform combined with infrared thermal imaging. Untreated IOLs served as controls. Optical performance was subsequently evaluated using a standardized optical bench according to ISO recommendations. Point spread function (PSF) and modulation transfer function (MTF) analyses were performed to quantify retinal image quality, light scattering, and optical degradation. Retinal light distribution was assessed using a high-resolution projection screen simulating the retinal image. Laser exposure produced permanent focal defects on the anterior optical surface of both IOL models, resulting in measurable optical degradation. Even the lowest laser exposure (five shots) generated detectable alterations in light propagation, characterized by increased peripheral light scattering, enlargement of the PSF halo, reduced central peak intensity, and irregular light distribution across the simulated retinal plane. Descriptively, increasing numbers of laser impacts were associated with more pronounced optical disturbances, particularly in the AcrySof IQ samples. MTF analysis demonstrated a reduction in optical performance across multiple spatial frequencies, indicating deterioration of image contrast and resolving power. Although both hydrophobic acrylic IOL models exhibited optical alterations after laser exposure, descriptive differences in the magnitude and distribution of light scatter suggested a possible influence of material composition, refractive index, and surface microarchitecture. These observations should be considered preliminary because of the limited sample size and absence of inferential statistical analysis. Under the present experimental conditions, Nd:YAG laser-induced pitting was associated with measurable structural and optical alterations in two hydrophobic acrylic IOL models. Surface defects alter retinal light distribution, increase forward light scatter, and reduce optical quality, providing a possible optical mechanism that may contribute to postoperative dysphotopsias, although clinical visual symptoms were not directly evaluated in this study. These findings highlight the importance of meticulous laser focusing on the posterior capsule to minimize inadvertent IOL damage and preserve postoperative visual quality. Further investigations combining optical bench analyses with patient-reported visual outcomes are warranted to better define the clinical significance of laser-induced IOL pitting. Full article

Background: This study aimed to identify the factors associated with self-reported visual difficulty and uptake of spectacle/contact lens correction among women of reproductive age in Malawi. Methods: We conducted a cross-sectional secondary analysis of the 2024 Malawi Demographic and Health Survey data. Outcomes were self-reported visual difficulty and use of spectacles/contact lenses. Age, residence, region, education, and marital status were examined as associated variables. Categorical variables were summarized using frequencies and percentages. Chi-square tests, multinomial and binary logistic regression models were used to assess associations. Results: The analysis included 5634 women aged 15–49 years; 78.3% lived in rural areas, and 62.4% had primary education. Self-reported visual difficulty was significantly associated with region, age, residence, education, and marital status (all p ≤ 0.004). Reported use of spectacle/contact lenses was also associated with these factors. Increasing age was associated with higher odds of reporting “some difficulty” seeing (OR 1.07, 95% CI 1.06–1.09). Compared with women in the Southern region, those from the Northern (OR 2.1, 95% CI 1.5–2.9) and Central regions (OR 1.6, 95% CI 1.2–2.1) had higher odds of reporting visual difficulty, with stronger associations for “a lot of difficulty” in the Central region (OR 4.3, 95% CI 2.1–8.6). Urban residence was associated with higher odds whereas being married/living together, divorced/separated, or widowed was associated with lower odds. Conclusion: Self-reported visual difficulty and use of spectacles/contact lenses varied by demographic and socioeconomic characteristics. Targeted strategies to improve access to affordable eye care may reduce barriers to uptake of corrective services and reduce visual impairment among women in Malawi. Full article

Patient-reported outcome measures (PROMs) in vision science are commonly evaluated using Cronbach’s alpha, yet Rasch-based statistics may provide different information about their reliability. This study compared Cronbach’s alpha, a Classical Test Theory (CTT) index, with Rasch person reliability and the person separation ratio across three vision-related questionnaires: the Symptom Questionnaire for Visual Dysfunctions (SQVD; n = 434), the Ocular Surface Disease Index (OSDI; n = 294), and the Quality of Vision questionnaire (QoV; n = 288), using retrospective data from unselected clinical populations. Cronbach’s alpha indicated acceptable internal consistency across all questionnaires (α = 0.80–0.87), whereas Rasch person reliability was lower (0.62–0.80) and person separation ratios ranged from 1.29 to 2.00, indicating more limited discrimination. Item reliability was generally high (0.90–0.97) overall but declined in subgroups with restricted score variability. Discrepancies were most pronounced in the OSDI, where estimates approached their theoretical floor when subgroups were defined by the questionnaire’s own scores. Cronbach’s alpha and Rasch-based statistics are not interchangeable and capture different aspects of measurement precision: alpha may overestimate internal consistency, whereas person reliability and the separation ratio provide complementary information about discriminatory capacity. These findings support reporting both CTT and Rasch-based reliability statistics when evaluating vision-related PROMs in clinical populations. Full article

Studies suggest that anticipation in sports-related tasks is better if the task maintains the coupling of perception and action required in competition. Study 1 addressed the question of whether gaze tracking varies between coupled tasks in baseball and softball batters. Fifteen subjects executed either a coupled task (partially swinging a bat at an approaching ball) or an uncoupled task (predicting the passing height of an approaching ball). The ball was stopped by a net 8 feet (2.44 m) in front of the subject. Rapid gaze shifts occurred for 53.0% of the pitches in the uncoupled task, and for 39.7% of the pitches in the coupled task (p = 0.039). The number of predictive gaze shifts toward the terminal ball location in each condition (i.e., the expected location of bat–ball contact in the coupled condition, and the observer in the uncoupled condition) did not vary between the conditions (p = 0.388). Study 2 examined whether gaze fixations on the net found in Study 1 occurred because passing height judgments could not be improved at distances closer than 8 feet from the observer. Passing height judgments were lower when the ball was allowed to pass by the observer, suggesting that subjects processed trajectory information within 8 feet. Full article

Alzheimer’s disease (AD) extends beyond the brain to the visual system, offering a promising window for pathology, monitoring, and intervention. This review synthesizes evidence on AD-related visual impairments across molecular, cellular, circuit, and cortical levels. We examine the eye–brain pathological relationship as a working framework, noting experimental evidence for brain-to-eye amyloid-β (Aβ) transport in mouse models and associations between retinal and cerebral pathology in humans, while emphasizing that bidirectional pathological transport has not been established. Structural and functional changes in the retina, optic nerve, and visual cortex are reviewed, alongside white matter damage and posterior cortical atrophy patterns. We evaluate emerging multimodal tools (OCTA, ERG, and hyperspectral imaging) that shift diagnosis toward an integrated “structure–vessel–function” assessment. We critically examine non-pharmacological interventions, including 40 Hz gamma stimulation and photobiomodulation, discussing their mechanisms, translational challenges, and the dissociation between structural and cognitive outcomes. We propose the visual system as a candidate pathological window, a quantitative monitoring platform, and an investigational intervention entry point in Alzheimer’s disease. However, clinical translation of these applications requires standardized acquisition protocols, prospective longitudinal validation, and robust mechanistic evidence. To advance this agenda, we identify three priorities: multimodal data integration, closed-loop neuromodulation strategies, and methodologically rigorous validation frameworks. Full article

Purpose: Keratoconus is a progressive corneal ectatic disorder that causes visual impairment, particularly in adolescents and young adults. Evidence on its epidemiology in Latin America and the Caribbean remains limited. This study aimed to estimate the prevalence of keratoconus and evaluate associated factors, including eye rubbing, sex, family history, and allergy history, in the region. Methods: A systematic search of PubMed, Scopus, PsycINFO, and Google Scholar was conducted on 15 December 2025 for observational studies published up to December 2025. Study selection and data extraction were performed independently by two reviewers, with disagreements resolved by consensus. Study quality was assessed using the Newcastle–Ottawa Scale. Pooled prevalence estimates and odds ratios (ORs) were calculated using a random-effects model with variance-stabilizing transformation. Heterogeneity was assessed using the I² statistic, and publication bias was explored using funnel plots and Egger’s test. Results: Seven prevalence studies were included in the primary meta-analysis following exclusion of three studies from the previous version of the review, with no additional eligible prevalence studies identified in the updated search. One additional nationwide registry-based study from Colombia was identified but excluded from the primary prevalence synthesis because it reported incidence derived from administrative diagnostic coding rather than clinically assessed prevalence. Among the seven prevalence studies, reported prevalence ranged from 0.50% to 2.88%. The pooled prevalence of keratoconus was 2.07% (95% CI: 1.53–2.79), with substantial heterogeneity (I² = 71.9%). Subgroup analyses suggested that prevalence estimates varied by study design, with lower estimates observed in community- and school-based studies and higher estimates in clinic-based studies. No statistically significant associations were identified for eye rubbing, sex, family history, or allergy history; however, these analyses should be interpreted cautiously due to small sample sizes, heterogeneous exposure definitions, and wide confidence intervals. Conclusions: Keratoconus prevalence estimates in Latin America and the Caribbean remain variable and should be interpreted cautiously due to substantial heterogeneity, differences in study design, variability in diagnostic criteria, and differences in case ascertainment. The findings highlight important evidence gaps and support the need for well-designed population-based studies using standardized diagnostic criteria to inform screening strategies, early detection, and eye-care planning in the region. Full article

Despite the widespread use of orthokeratology (ortho-k), the diurnal behavior of corneal geometry after lens removal remains unclear. This prospective observational study evaluated diurnal variations in corneal geometry, refractive error, and visual performance in ortho-k wearers using global and sector-based corneal analyses. Nineteen eyes from ten ortho-k wearers were examined at five time points over a 10-h period following overnight lens wear. Corneal thickness, anterior and posterior corneal curvature, corneal asphericity, autorefractometry, and visual acuity were assessed. Corneal elevation data were reconstructed using Zernike polynomial expansions, and regional analyses were performed using concentric annular sectors. Diurnal amplitudes were compared with a healthy control cohort evaluated using the same protocol. Corneal thickness progressively decreased throughout the day (p < 0.001). Anterior corneal curvature showed progressive steepening (p ≤ 0.011), whereas posterior corneal curvature exhibited significant flattening (p ≤ 0.018). A progressive myopic refractive shift was also observed, with a spherical equivalent amplitude of −1.03 D (p = 0.002). Despite these changes, visual acuity remained stable (p = 0.248). Compared with healthy controls, ortho-k wearers showed greater amplitudes of central corneal thickness and anterior corneal curvature changes. These findings indicate that ortho-k may enhance normal diurnal corneal changes while maintaining visual acuity. Full article

The magnitude and short-term recovery of residual objective myopic bias after a brief, clinically plausible over-minus exposure during distance refraction remain insufficiently quantified. This study quantified the short-term residual objective myopic shift following 10 s of transient myopic overcorrection of 0.50 D or 1.00 D in young adults with myopia. Twenty healthy young adults with myopia and low astigmatism underwent open-field automated objective over-refraction (OR) while viewing a high-contrast 5 m target. After trial lenses induced a moderate myopic state, each participant completed three randomized 10 s lens conditions: 0.50 D undercorrection, 0.50 D overcorrection, and 1.00 D overcorrection. The primary endpoint was OR at 5 s after restoration of the objective neutral correction. Both overcorrection conditions produced significantly more negative OR than undercorrection at 5 s; exploratory analyses showed the same pattern at 10 s. The shift was evident at 5 and 10 s after restoration of the objective neutral correction and, by 30 s, was no longer statistically significant and appeared clinically negligible. This bias should be considered when OR measurements obtained shortly after over-minus lens exposure are used to inform subsequent subjective refinement. Full article

Dry Eye Disease (DED) is a multifactorial condition increasingly affecting young populations, including medical students, due to intensive screen use, prolonged near work, and demanding academic environments. This study aimed to estimate the prevalence of DED-related outcomes among medical students and to examine how estimates vary according to diagnostic methods, methodological characteristics, and publication period. A systematic review with meta-analysis was conducted. PubMed, Scopus, Web of Science (including SciELO), and EMBASE were searched from January 2000 to March 2026. A random-effects model was applied, and subgroup, sensitivity, and exploratory meta-regression analyses were performed. Twenty-seven studies were included, comprising 12,501 participants. The pooled prevalence of DED-related outcomes was 47.4% (95% CI: 38.4–56.4%); however, between-study heterogeneity was extreme (I² = 99%). Therefore, this estimate should be interpreted as an approximate summary of a highly heterogeneous evidence base rather than as a definitive global epidemiological value. Prevalence estimates varied according to diagnostic approach, particularly between self-report, symptom questionnaires, and clinical tests. Exploratory meta-regression suggested a positive association with publication year, but these analyses did not meaningfully resolve heterogeneity and should not be interpreted as causal evidence of a temporal increase. Standardized diagnostic approaches combining symptoms and ocular surface signs are needed to improve comparability across studies and inform preventive visual-health strategies in medical education. Full article

Background/Objectives: High astigmatism remains challenging in keratorefractive lenticule extraction because small errors in centration or cyclotorsion may affect astigmatic correction. This study evaluated early refractive and astigmatic vector outcomes after small-incision lenticule extraction (SMILE) Pro using the VISUMAX 800 in eyes with high astigmatism. Methods: This prospective interventional cohort study was conducted at Cung Hong Son International Eye Hospital, Hanoi, Vietnam. Refractive outcomes, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, astigmatic vector analysis, and intraoperative and postoperative complications, were evaluated up to 3 months postoperatively. Results: A total of 160 eyes from 102 patients were included in the final analysis. The mean age was 23.7 ± 4.7 years, and 63.7% of participants were female. The mean preoperative spherical equivalent (SEQ) was −7.21 ± 2.03 D, and the mean preoperative refractive cylinder was −2.51 ± 0.56 D. Mean postoperative SEQ was −0.10 ± 0.38 D at 1 month and 0.02 ± 0.31 D at 3 months. At 3 months, 99% and 84% of eyes achieved UDVA of 0.8 decimal or better and 0.9 decimal or better, respectively. The mean residual refractive cylinder was −0.52 ± 0.28 D, with 69% and 98% of eyes achieving a residual cylinder ≤0.50 D and ≤1.00 D, respectively. All eyes had an angle of error within ±15°. The safety index was 1.01, and no eyes lost two or more lines of CDVA. Conclusions: SMILE Pro performed with the VISUMAX 800 provided favorable early 3-month refractive and astigmatic vector outcomes with a satisfactory safety profile in eyes with high astigmatism. Full article

Spatial working memory (SWM) has been characterised as a flexible resource that determines the precision with which memoranda are stored. The ‘cortical map’ proposal predicts that resource allocation, and therefore mnemonic precision, is limited by the availability of cortical space to represent memoranda. This hypothesis was tested using a continuous spatial localisation task in which memory items were presented at three eccentricities and set sizes of 1–8. Localisation error increased systematically with eccentricity, as predicted by the cortical maps hypothesis. Mixture-modelling analyses indicated that the eccentricity effect was primarily driven by increases in imprecision at small set sizes (set sizes 1–5). In contrast, when set size exceeded five items, guessing made an increasingly important contribution to localisation error, suggesting that representations of peripheral locations become more vulnerable to memory failure under high memory loads. Misbinding errors were most prominent for locations nearest fixation, likely reflecting reduced inter-item spacing at small eccentricities. Stimuli were not scaled to compensate for cortical magnification, but the observed increase in imprecision closely matched predictions derived from a cortical magnification function. Together, these findings support the cortical maps hypothesis and indicate that spatial working memory representations compete for limited representational resources within the spatial maps that guide action. Full article

Myopia is an increasingly common refractive disorder in children, with growing concern regarding the potential role of screen time and digital device use in its development and progression. This systematic review assessed the association between screen-related behaviours and myopia in European children and adolescents. A systematic search of Ovid Embase, Ovid MEDLINE, Scopus, Web of Science and Cochrane/CENTRAL was conducted in accordance with PRISMA guidance. Original English-language studies published within the last 10 years were included if they involved participants aged <18 years, were conducted in Europe, and investigated screen time, digital device use, near-work behaviour or related lifestyle exposures in relation to myopia-related outcomes. A total of 1196 records were identified across the databases. After duplicate removal, title and abstract screening, and full-text assessment, 14 studies were included. Overall, the evidence suggested an association between screen-related behaviours, prolonged near work, reduced outdoor exposure and myopia-related outcomes in European children. However, findings were heterogeneous, and screen exposure was often measured using broad or proxy variables, including total screen time, smartphone use, internet data consumption, computer use, handheld near-screen use and COVID-19-related lifestyle change. Outdoor activity appeared to be a protective factor, while parental myopia was an important risk factor and confounder. Most included studies were observational, many were cross-sectional, and several relied on self- or parent-reported exposure measures, limiting causal inference and introducing potential recall bias. Overall, the certainty of evidence was low to very low. Practical advice should therefore be framed around balanced digital device use, regular breaks from prolonged near work, appropriate viewing distances and increased outdoor activity, while further longitudinal studies using objective screen-use measures, cycloplegic refraction and axial length outcomes are needed to clarify causality. Full article