Proportion and risk factors of zonulopathy in patients with age-related cataract.

Purpose: To investigate the proportion of zonulopathy in patients with age-related cataract, and further explore demographics and ocular characteristics, as well as potential risk factors. Methods: Hospital-based, observational, cross-sectional study. We enrolled consecutive patients who were 45 years or older and diagnosed with age-related cataract and underwent surgery between October 2022 and April 2023 at the Division of Cataract, Beijing Tongren Hospital. Zonulopathy was diagnosed based on intraoperative signs. We calculated the total proportion, age, and gender specific proportions of zonulopathy. We compared the demographic and ocular characteristics between the cases with and without zonulopathy. Univariate and multivariate logistic regression analyses were employed to determine the risk factors associated with the presence of zonulopathy in patients with age-related cataract. Results: A total of 640 age-related cataract patients with a median age of 70.0 (64.0-77.0) were enrolled. Zonulopathy was diagnosed intraoperatively in 70 patients (10.9%). Compared with the patients having no zonulopathy, those with zonulopathy were likely to be older (P < 0.001), have a shallower central ACD (P < 0.001), a thicker lens (P < 0.001) and a shorter AL (P = 0.010). Logistic regression analyses showed that the risk predictors associated with the presence of zonulopathy in patients with age-related cataract were older age (OR, 1.042; P = 0.035) and shallower central ACD (OR, 0.834; P < 0.001). Conclusion: Zonulopathy in age-related cataract patients is not an uncommon finding. Clinicians should be mindful of zonulopathy in patient population with advanced age and shallower ACD.

Performance of anterior segment OCT-based algorithms in the opportunistic screening for primary angle-closure disease.

Purpose: This study aimed to investigate the performance of deep learning algorithms in the opportunistic screening for primary angle-closure disease (PACD) using combined anterior segment parameters. Methods: This was an observational, cross-sectional hospital-based study. Patients with PACD and healthy controls who underwent comprehensive eye examinations, including gonioscopy and anterior segment optical coherence tomography (ASOCT) examinations under both light and dark conditions, were consecutively enrolled from the Department of Ophthalmology at the Beijing Tongren Hospital between November 2020 and June 2022. The anterior chamber, anterior chamber angle, iris, and lens parameters were assessed using ASOCT. To build the prediction models, backward logistic regression was utilized to select the variables to discriminate patients with PACD from normal participants, and the area under the receiver operating characteristic curve was used to evaluate the efficacy of the opportunistic screening. Results: The data from 199 patients (199 eyes) were included in the final analysis and divided into two groups: PACD (109 eyes) and controls (90 eyes). Angle opening distance at 500 µm, anterior chamber area, and iris curvature measured in the light condition were included in the final prediction models. The area under the receiver operating characteristic curve was 0.968, with a sensitivity of 91.74 % and a specificity of 91.11 %. Conclusion: ASOCT-based algorithms showed excellent diagnostic performance in the opportunistic screening for PACD. These results provide a promising basis for future research on the development of an angle-closure probability scoring system for PACD screening.

Anomaly Detection for Medical Images Using Heterogeneous Auto-Encoder.

Anomaly detection is an important task for medical image analysis, which can alleviate the reliance of supervised methods on large labelled datasets. Most existing methods use a pixel-wise self-reconstruction framework for anomaly detection. However, there are two challenges of these studies: 1) they tend to overfit learning an identity mapping between the input and output, which leads to failure in detecting abnormal samples; 2) the reconstruction considers the pixel-wise differences which may lead to an undesirable result. To mitigate the above problems, we propose a novel heterogeneous Auto-Encoder (Hetero-AE) for medical anomaly detection. Our model utilizes a convolutional neural network (CNN) as the encoder and a hybrid CNN-Transformer network as the decoder. The heterogeneous structure enables the model to learn the intrinsic information of normal data and enlarge the difference on abnormal samples. To fully exploit the effectiveness of Transformer in the hybrid network, a multi-scale sparse Transformer block is proposed to trade off modelling long-range feature dependencies and high computational costs. Moreover, the multi-stage feature comparison is introduced to reduce the noise of pixel-wise comparison. Extensive experiments on four public datasets (i.e., retinal OCT, chest X-ray, brain MRI, and COVID-19) verify the effectiveness of our method on different imaging modalities for anomaly detection. Additionally, our method can accurately detect tumors in brain MRI and lesions in retinal OCT with interpretable heatmaps to locate lesion areas, assisting clinicians in diagnosing abnormalities efficiently.

PatchCL-AE: Anomaly detection for medical images using patch-wise contrastive learning-based auto-encoder.

Anomaly detection is an important yet challenging task in medical image analysis. Most anomaly detection methods are based on reconstruction, but the performance of reconstruction-based methods is limited due to over-reliance on pixel-level losses. To address the limitation, we propose a patch-wise contrastive learning-based auto-encoder for medical anomaly detection. The key contribution is the patch-wise contrastive learning loss that provides supervision on local semantics to enforce semantic consistency between corresponding input-output patches. Contrastive learning pulls corresponding patch pairs closer while pushing non-corresponding ones apart between input and output, enabling the model to learn local normal features better and improve discriminability on anomalous regions. Additionally, we design an anomaly score based on local semantic discrepancies to pinpoint abnormalities by comparing feature difference rather than pixel variations. Extensive experiments on three public datasets (i.e., brain MRI, retinal OCT, and chest X-ray) achieve state-of-the-art performance, with our method achieving over 99% AUC on retinal and brain images. Both the contrastive patch-wise supervision and patch-discrepancy score provide targeted advancements to overcome the weaknesses in existing approaches.

Natural History and Risk Factors for Glaucoma Progression in Chinese Patients With Normal-Tension Glaucoma.

Purpose: To characterize the natural history of normal-tension glaucoma (NTG) in Chinese patients. Methods: The prospective observational cohort study included patients with untreated NTG with a minimum follow-up of 2 years. Functional progression was defined by visual field (VF) deterioration, while structural progression was characterized by thinning of the retinal nerve fiber layer (RNFL) or ganglion cell inner plexiform layer (GCIPL). Results: Among 84 participants (mean age, 60.5 years; mean deviation, -5.01 decibels [dB]) with newly diagnosed NTG followed for an average of 69.7 months, 63.1% progressed during the observation period. Specifically, 29.8% progressed by VF, and 48.8% progressed by either RNFL or GCIPL. In Cox proportional hazards analysis, disc hemorrhage (hazard ratio [HR], 2.82; 95% confidence interval [CI], 1.48-5.35), female gender (HR, 1.98; 95% CI, 1.08-3.62), and mean IOP during the follow-up period (HR, 1.14 per mm Hg; 95% CI, 1.00-1.31) were significant predictors of glaucomatous progression. Additionally, longer axial length (AL; HR, 0.57 per millimeter; 95% CI, 0.35-0.94) was protective against VF progression faster than -0.50 dB/y, and higher minimum diastolic blood pressure (DBP; HR, 0.96 per mm Hg; 95% CI, 0.92-1.00) was protective against structural progression. Conclusions: Nearly two-thirds of untreated Chinese patients with NTG progressed over an average follow-up of 70 months by VF, RNFL, or GCIPL. Disc hemorrhage, female gender, higher mean IOP, shorter AL, and lower minimum DBP were significant predictors for disease progression.

Efficacy of far infrared functional glasses in the treatment of meibomian gland dysfunction-related dry eye.

Meibomian gland dysfunction (MGD)-related dry eye disease (DED) is a significant subtype of DED. In this research, we investigate the effectiveness of far infrared (FIR) functional glasses in the treatment of MGD-related DED. According to the TFO DEWS II diagnostic criteria, 61 eyes with MGD-related DED were included. All participants wore functional FIR glasses throughout the day for a period of 4 weeks and were followed up three times during the treatment. All subjects were followed up thoroughly in accordance with the DED clinical examination procedure. Ultimately, the treatment's impact was assessed. We found the Visual Analogue Scale and Ocular Surface Disease Index scores after FIR treatment were significantly lower than the baseline values (p < 0.05). Compared with the baseline, fluorescein tear breakup time and corneal fluorescein staining score after FIR treatment were significantly improved (p < 0.05). The eyelid margin signs, meibum quality, and meibomian gland expressibility after the 4-week treatment were significantly better than those at baseline (p < 0.05). We can see that wearing the FIR functional glasses significantly relieves the symptoms and signs of patients. We believe FIR therapy could be considered as a new method of MGD-related DED.

Long-term outcomes of anti-vascular endothelial growth factor therapy with and without posterior scleral reinforcement on myopic maculopathy in myopic choroidal neovascularization eyes.

BACKGROUND: Anti-vascular endothelial growth factor (anti-VEGF) therapy is used for myopic choroidal neovascularization (mCNV). Patchy chorioretinal atrophy (pCRA) enlargement has been reported in mCNV cases associated with vision loss. Our aim was to compare the long-term effectiveness of anti-VEGF therapy alone versus anti-VEGF followed by posterior scleral reinforcement (PSR) in controlling myopic maculopathy in mCNV eyes. METHODS: We performed a retrospective review of the medical records of 95 high myopia patients (refractive error ≥ 6.00 diopters, axial length ≥ 26.0 mm) with mCNV. Patients were treated with anti-VEGF alone (group A) or anti-VEGF followed by PSR (group B). The following data were collected: refractive error, best corrected visual acuity (BCVA), ophthalmic fundus examination, ocular coherence tomography and ocular biometry at 12 and 24 months pre- and postoperatively. The primary outcomes were changes in pCRA and BCVA. RESULTS: In 26 eyes of 24 patients, the mean pCRA size significantly increased from baseline (0.88 ± 1.69 mm2) to 12 months (1.57 ± 2.32 mm2, t = 3.249, P = 0.003) and 24 months (2.17 ± 2.79 mm2, t = 3.965, P = 0.001) postoperatively. The increase in perilesional pCRA in group B (n = 12) was 98.2% and 94.2% smaller than that in group A (n = 14) at 12 and 24 months (Beta 0.57 [95% CI 0.01, 191 1.13], P = 0.048). In group B, 7 eyes (58.3%) gained more than 2 lines of BCVA compared with only 4 eyes (28.6%) in group A at 24 months. CONCLUSION: Anti-VEGF therapy followed by PSR achieved better outcomes than anti-VEGF therapy alone in controlling the development of myopic maculopathy in mCNV and may constitute a better treatment option by securing a better long-term VA outcome.

Phacogoniotomy versus phacotrabeculectomy for advanced primary angle-closure glaucoma with cataract: A randomized non-inferiority trial.

PURPOSE: To investigate the effectiveness and safety of phacogoniotomy versus phacotrabeculectomy (PVP) among patients with advanced primary angle-closure glaucoma (PACG) and cataracts. DESIGN: Multicenter, randomized controlled, non-inferiority trial. METHODS: A total of 124 patients (124 eyes) with advanced PACG and cataracts were enrolled, with 65 in the phacogoniotomy group and 59 in the phacotrabeculectomy group. Patients were followed up for 12 months with standardized evaluations. The primary outcome was the reduction in intraocular pressure (IOP) from baseline to 12 months postoperatively, of which a non-inferiority margin of 4 mmHg was evaluated. Secondary outcomes included the cumulative surgical success rate, postoperative complications, and changes in the number of glaucoma medications. RESULTS: After 12 months, phacogoniotomy demonstrated non-inferiority to phacotrabeculectomy in terms of IOP reduction, with mean IOP reductions of - 26.1 mmHg and - 25.7 mmHg (P = 0.383), respectively, from baseline values of around 40 mmHg. Both groups experienced a significant reduction in the mean number of medications used postoperatively (P < 0.001). The cumulative success rate was comparable between the groups (P = 0.890). However, phacogoniotomy had a lower rate of postoperative complications and interventions (12.3% and 4.6%) compared to phacotrabeculectomy (23.7% and 20.3% respectively). The phacogoniotomy group reported shorter surgery time (22.1 ± 6.5 vs. 38.8 ± 11.1 min; P = 0.030) and higher quality of life (EQ-5D-5 L) improvement at 12 months (7.0 ± 11.5 vs. 3.0 ± 12.9, P = 0.010) than the phacotrabeculectomy group. CONCLUSIONS: Phacogoniotomy was non-inferior to phacotrabeculectomy in terms of IOP reduction for advanced PACG and cataracts. Additionally, phacogoniotomy provided a shorter surgical time, lower postoperative complication rate, fewer postoperative interventions, and better postoperative quality of life.

iPSC-derived cells stimulate ABCG2+ /NES+ endogenous trabecular meshwork cell proliferation and tissue regeneration.

A major risk factor for glaucoma, the first leading cause of irreversible blindness worldwide, is the decellularisation of the trabecular meshwork (TM) in the conventional outflow pathway. Stem cell-based therapy, particularly the utilisation of induced pluripotent stem cells (iPSCs), presents an enticing potential for tissue regeneration and intraocular pressure (IOP) maintenance in glaucoma. We have previously observed that differentiated iPSCs can stimulate endogenous cell proliferation in the TM, a pivotal factor in TM regeneration and aqueous humour outflow restoration. In this study, we investigated the response of TM cells in vivo after interacting with iPSC-derived cells and identified two subpopulations responsible for this relatively long-term tissue regeneration: ATP Binding Cassette Subfamily G Member 2 (ABCG2)-positive cells and Nestin (NES)-positive cells. We further uncovered that alterations of these responsive cells are linked to ageing and different glaucoma etiologies, suggesting that ABCG2+ subpopulation decellularization could serve as a potential risk factor for TM decellularization in glaucoma. Taken together, our findings illustrated the proliferative subpopulations in the conventional outflow pathway when stimulated with iPSC-derived cells and defined them as TM precursors, which may be applied to develop novel therapeutic approaches for glaucoma.

Ferroptosis in Glaucoma: A Promising Avenue for Therapy.

Glaucoma, a blind-leading disease largely since chronic pathological intraocular high pressure (ph-IOP). Hitherto, it is reckoned incurable for irreversible neural damage and challenges in managing IOP. Thus, it is significant to develop neuroprotective strategies. Ferroptosis, initially identified as an iron-dependent regulated death that triggers Fenton reactions and culminates in lipid peroxidation (LPO), has emerged as a focal point in multiple tumors and neurodegenerative diseases. Researches show that iron homeostasis play critical roles in the optic nerve (ON) and retinal ganglion cells (RGCs), suggesting targeted treatments could be effective. In glaucoma, apart from neural lesions, disrupted metal balance and increased oxidative stress in trabecular meshwork (TM) are observed. These disturbances lead to extracellular matrix excretion disorders, known as sclerotic mechanisms, resulting in refractory blockages. Importantly, oxidative stress, a significant downstream effect of ferroptosis, is also a key factor in cell senescence. It plays a crucial role in both the etiology and risk of glaucoma. Moreover, ferroptosis also induces non-infectious inflammation, which exacerbate glaucomatous injury. Therefore, the relevance of ferroptosis in glaucoma is extensive and multifaceted. In this review, the study delves into the current understanding of ferroptosis mechanisms in glaucoma, aiming to provide clues to inform clinical therapeutic practices.

Single-cell transcriptomic Atlas of aging macaque ocular outflow tissues.

The progressive degradation in the trabecular meshwork (TM) is related to age-related ocular diseases like primary open-angle glaucoma. However, the molecular basis and biological significance of the aging process in TM have not been fully elucidated. Here, we established a dynamic single-cell transcriptomic landscape of aged macaque TM, wherein we classified the outflow tissue into 12 cell subtypes and identified mitochondrial dysfunction as a prominent feature of TM aging. Furthermore, we divided TM cells into 13 clusters and performed an in- depth analysis on cluster 0, which had the highest aging score and the most significant changes in cell proportions between the two groups. Ultimately, we found that the APOE gene was an important differentially expressed gene in cluster 0 during the aging process, highlighting the close relationship between cell migration and extracellular matrix regulation, and TM function. Our work further demonstrated that silencing the APOE gene could increase migration and reduce apoptosis by releasing the inhibition on the PI3K-AKT pathway and downregulating the expression of extracellular matrix components, thereby increasing the aqueous outflow rate and maintaining intraocular pressure within the normal range. Our work provides valuable insights for future clinical diagnosis and treatment of glaucoma.

Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

OBJECTIVE: To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. METHODS: This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. RESULTS: Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). CONCLUSIONS: Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.

Serine to proline mutation at position 341 of MYOC impairs trabecular meshwork function by causing autophagy deregulation.

Glaucoma is a highly heritable disease, and myocilin was the first identified causal and most common pathogenic gene in glaucoma. Serine-to-proline mutation at position 341 of myocilin (MYOCS341P) is associated with severe glaucoma phenotypes in a five-generation primary open-angle glaucoma family. However, the underlying mechanisms are underexplored. Herein, we established the MYOCS341P transgenic mouse model and characterized the glaucoma phenotypes. Further, we systematically explored the functional differences between wild-type and MYOCS341P through immunoprecipitation, mass spectrometry, and RNA-seq analyses. We found that MYOCS341P transgenic mice exhibit glaucoma phenotypes, characterized by reduced aqueous humor outflow, elevated intraocular pressure, decreased trabecular meshwork (TM) cell number, narrowed Schlemm's canal, retinal ganglion cell loss, and visual impairment. Mechanistically, the secretion of dysfunctional MYOCS341P accumulated in the endoplasmic reticulum (ER), inducing ER stress and dysregulation of autophagy, thereby promoting TM cell death. We describe an effective transgenic model for mechanistic studies and the screening of therapeutic targets. Our data generated from high-throughput analyses help elucidate the mechanism underlying mutant MYOC-related glaucoma.

Quantitative ultrasound image assessment of the optic nerve subarachnoid space during 90-day head-down tilt bed rest.

The elevation in the optic nerve sheath (ONS) pressure (ONSP) due to microgravity-induced headward fluid shift is the primary hypothesized contributor to SANS. This longitudinal study aims to quantify the axial plane of the optic nerve subarachnoid space area (ONSSA), which is filled with cerebrospinal fluid (CSF) and expands with elevated ONSP during and after head-down tilt (HDT) bed rest (BR). 36 healthy male volunteers (72 eyes) underwent a 90-day strict 6° HDT BR. Without obtaining the pre-HDT data, measurements were performed on days 30, 60, and 90 during HDT and at 6 recovery time points extended to 180-days (R + 180) in a supine position. Portable B-scan ultrasound was performed using the 12 MHz linear array probe binocularly. The measurements of the ONS and the calculation of the ONSSA were performed with ImageJ 1.51 analysis software by two experienced observers in a masked manner. Compared to R + 180, the ONSSA on HDT30, HDT60, and HDT90 exhibited a consistently significant distention of 0.44 mm2 (95% CI: 0.13 to 0.76 mm2, P = 0.001), 0.45 mm2 (95% CI: 0.15 to 0.75 mm2, P = 0.001), and 0.46 mm2 (95% CI: 0.15 to 0.76 mm2, P < 0.001), respectively, and recovered immediately after HDT on R + 2. Such small changes in the ONSSA were below the lateral resolution limit of ultrasound (0.4 mm) and may not be clinically relevant, possibly due to ONS hysteresis causing persistent ONS distension. Future research can explore advanced quantitative portable ultrasound-based techniques and establish comparisons containing the pre-HDT measurements to deepen our understanding of SANS.

Barriers to uptake of cataract surgery among elderly patients in rural China: a cross-sectional study.

OBJECTIVE: To investigate factors that differentiate elderly adults in rural China who accept free vision screening and cataract surgery from those who could benefit from vision care but refuse it when offered. DESIGN: We conducted a population-based, cross-sectional study between October and December 2016. Logistic regression models were used to examine the predictors of accepting free vision screening and cataract surgery. SETTING: Rural communities in Handan, China. PARTICIPANTS: Adults aged 50 years or older, with presenting visual acuity ≤6/18 in the better seeing eye, suspected by examining ophthalmologist to be due to cataract. RESULTS: Among 613 persons with cataract identified on a population basis, 596 (97.2%) completed the household survey (mean (SD) age, 71.5 (10.0) years; 79.8% female). A total of 214 persons (35.9%) refused participation, while 382 (64.1%) took part in the vision screening. A total of 193 (50.5%) participants were found eligible for surgery, while 189 (49.5%) were not. Among 99 randomly selected participants who were offered immediate free surgery, surgery was accepted by 77 participants (77.8%) and refused by 22 (22.2%). In the multivariate model, being engaged in income-generating activities (p<0.01), self-reported better physical capacity (p<0.001) and having had a recent physical examination (p=0.01) were significantly associated with acceptance of vision screening. The only variable significantly associated with acceptance of surgery was presenting visual acuity, with better vision inversely associated with acceptance of surgery (p<0.05) models. CONCLUSION: Our results suggest that refusal of basic eye examinations may be at least as important a determinant of low surgical rates in rural China as lack of acceptance of surgery itself.

Altered stability of dynamic brain functional architecture in primary open-angle glaucoma: a surface-based resting-state fMRI study.

Delineating the neuropathological characteristics of primary open-angle glaucoma (POAG) is critical for understanding its pathophysiology. While temporal stability represents a crucial aspect of the brain's functional architecture, the specific patterns underlying its contribution to POAG remain unclear. This study aims to analyze the brain functional abnormalities in POAG using functional stability, a dynamic functional connectivity (DFC) approach based on resting-state functional magnetic resonance imaging (rs-fMRI). Seventy patients with POAG and forty-five healthy controls underwent rs-fMRI and ophthalmological examinations. The stability of DFC was calculated as the concordance of DFC over time using a sliding-window approach, and the differences in stability between the two groups were compared. Subsequently, Spearman's correlation analyses were conducted to examine the relationship between functional stability and clinical indicators. Compared with healthy controls, patients with POAG exhibited significantly decreased functional stability in the visual network, including the early visual center, ventral and dorsal stream visual cortex in both hemispheres. Conversely, stability values increased in the bilateral inferior parietal gyrus and right inferior frontal cortex. In POAG patients, the dynamic stability of the left early visual cortex and ventral stream visual cortex correlated with the mean deviation of visual field defects (r = 0.251, p = 0.037). The evidence from this study suggests that functional stability may provide a new understanding of brain alterations in the progression of POAG.

Separation of polysaccharides from Lycium barbarum L. by high-speed countercurrent chromatography with aqueous two-phase system.

The traditional method for isolation and purification of polysaccharides is time-consuming. It often involves toxic solvents that destroy the function and structure of the polysaccharides, thus limiting in-depth research on the essential active ingredient of Lycium barbarum L. Therefore, in this study, high-speed countercurrent chromatography (HSCCC) and aqueous two-phase system (ATPS) were combined for the separation of crude polysaccharides of Lycium barbarum L. (LBPs). Under the optimized HSCCC conditions of PEG1000-K2HPO4-KH2PO4-H2O (12:10:10:68, w/w), 1.0 g of LBPs-ILs was successfully divided into three fractions (126.0 mg of LBPs-ILs-1, 109.9 mg of LBPs-ILs-2, and 65.4 mg of LBPs-ILs-3). Moreover, ATPS was confirmed as an efficient alternative method of pigment removal for LBPs purification, with significantly better decolorization (97.1 %) than the traditional H2O2 method (88.5 %). Then, the different partitioning behavior of LBPs-ILs in the two-phase system of HSCCC was preliminarily explored, which may be related to the difference in monosaccharide composition of polysaccharides. LBPs-ILs-1 exhibited better hypoglycemic activities than LBPs-ILs-2 and LBPs-ILs-3 in vitro. Therefore, HSCCC, combined with aqueous two-phase system, was an efficient separation and purification method with great potential for separating and purifying active polysaccharides in biological samples.

Adaptive enhancement of cataractous retinal images for contrast standardization.

Cataract affects the quality of fundus images, especially the contrast, due to lens opacity. In this paper, we propose a scheme to enhance different cataractous retinal images to the same contrast as normal images, which can automatically choose the suitable enhancement model based on cataract grading. A multi-level cataract dataset is constructed via the degradation model with quantified contrast. Then, an adaptive enhancement strategy is introduced to choose among three enhancement networks based on a blurriness classifier. The blurriness grading loss is proposed in the enhancement models to further constrain the contrast of the enhanced images. During test, the well-trained blurriness classifier can assist in the selection of enhancement networks with specific enhancement ability. Our method performs the best on the synthetic paired data on PSNR, SSIM, and FSIM and has the best PIQE and FID on 406 clinical fundus images. There is a 7.78% improvement for our method compared with the second on the introduced [Formula: see text] score without over-enhancement according to [Formula: see text], which demonstrates that the proper enhancement by our method is close to the high-quality images. The visual evaluation on multiple clinical datasets also shows the applicability of our method for different blurriness. The proposed method can benefit clinical diagnosis and improve the performance of computer-aided algorithms such as vessel tracking and vessel segmentation.

Effect of Different Postures on Intraocular Pressure in Open-Angle Glaucoma.

INTRODUCTION: This study aims to investigate the pattern of intraocular pressure (IOP) changes in different postures among patients with open-angle glaucoma (OAG). METHODS: A observational study was conducted on a total of 74 patients with OAG (148 eyes). IOP measurements were taken in a variety of positions, including supine, left lateral decubitus, right lateral decubitus, head tilted downwards position with immediate head-up (transient head tilted downwards), seated, seated with head tilted downwards, standing, and walking. Each position was held for 5 min before measurement. In all positions, the patient maintains both eyes looking forward and remains alert. In the head tilted downwards position, the angle of head tilt with respect to the sagittal plane was 30°. RESULTS: The overall trend of IOP changes showed a significant decrease with an increase in the position height (r = 0.037, p < 0.001). The IOP was significantly higher in the supine, left lateral decubitus, right lateral decubitus, and head tilted downwards positions than in the seated position (p < 0.001). Compared with the seated position with eyes at primary gaze, IOP decreased significantly when standing (p = 0.008) or walking (p < 0.001). The IOP in the left lateral decubitus and right lateral decubitus was significantly higher than in the supine position (p = 0.008, p = 0.001, respectively). The IOP decreased significantly during walking compared with standing (p < 0.001). CONCLUSIONS: The magnitude of IOP strongly correlates with the body position during IOP measurement. The head tilted downwards, supine, left lateral decubitus, and right lateral decubitus positions result in a higher IOP than IOP at the seated position. Patients with OAG can potentially reduce IOP fluctuations by adjusting their daily postures.