Metabolomics identifies and validates serum androstenedione as novel biomarker for diagnosing primary angle closure glaucoma and predicting the visual field progression.

Background: Primary angle closure glaucoma (PACG) is the leading cause of irreversible blindness in Asia, and no reliable, effective diagnostic, and predictive biomarkers are used in clinical routines. A growing body of evidence shows metabolic alterations in patients with glaucoma. We aimed to develop and validate potential metabolite biomarkers to diagnose and predict the visual field progression of PACG. Methods: Here, we used a five-phase (discovery phase, validation phase 1, validation phase 2, supplementary phase, and cohort phase) multicenter (EENT hospital, Shanghai Xuhui Central Hospital), cross-sectional, prospective cohort study designed to perform widely targeted metabolomics and chemiluminescence immunoassay to determine candidate biomarkers. Five machine learning (random forest, support vector machine, lasso, K-nearest neighbor, and GaussianNaive Bayes [NB]) approaches were used to identify an optimal algorithm. The discrimination ability was evaluated using the area under the receiver operating characteristic curve (AUC). Calibration was assessed by Hosmer-Lemeshow tests and calibration plots. Results: Studied serum samples were collected from 616 participants, and 1464 metabolites were identified. Machine learning algorithm determines that androstenedione exhibited excellent discrimination and acceptable calibration in discriminating PACG across the discovery phase (discovery set 1, AUCs=1.0 [95% CI, 1.00-1.00]; discovery set 2, AUCs = 0.85 [95% CI, 0.80-0.90]) and validation phases (internal validation, AUCs = 0.86 [95% CI, 0.81-0.91]; external validation, AUCs = 0.87 [95% CI, 0.80-0.95]). Androstenedione also exhibited a higher AUC (0.92-0.98) to discriminate the severity of PACG. In the supplemental phase, serum androstenedione levels were consistent with those in aqueous humor (r=0.82, p=0.038) and significantly (p=0.021) decreased after treatment. Further, cohort phase demonstrates that higher baseline androstenedione levels (hazard ratio = 2.71 [95% CI: 1.199-6.104], p=0.017) were associated with faster visual field progression. Conclusions: Our study identifies serum androstenedione as a potential biomarker for diagnosing PACG and indicating visual field progression. Funding: This work was supported by Youth Medical Talents - Clinical Laboratory Practitioner Program (2022-65), the National Natural Science Foundation of China (82302582), Shanghai Municipal Health Commission Project (20224Y0317), and Higher Education Industry-Academic-Research Innovation Fund of China (2023JQ006).

Binocular head-mounted chromatic pupillometry can detect structural and functional loss in glaucoma.

Aim: The aim of this study is to evaluate the utility of binocular chromatic pupillometry in detecting impaired pupillary light response (PLR) in patients with primary open-angle glaucoma (POAG) and to assess the feasibility of using binocular chromatic pupillometer in opportunistic POAG diagnosis in community-based or telemedicine-based services. Methods: In this prospective, cross-sectional study, 74 patients with POAG and 23 healthy controls were enrolled. All participants underwent comprehensive ophthalmologic examinations including optical coherence tomography (OCT) and standard automated perimetry (SAP). The PLR tests included sequential tests of full-field chromatic stimuli weighted by rods, intrinsically photosensitive retinal ganglion cells (ipRGCs), and cones (Experiment 1), as well as alternating chromatic light flash-induced relative afferent pupillary defect (RAPD) test (Experiment 2). In Experiment 1, the constricting amplitude, velocity, and time to maximum constriction/dilation were calculated in three cell type-weighted responses, and the post-illumination response of ipRGC-weighted response was evaluated. In Experiment 2, infrared pupillary asymmetry (IPA) amplitude and anisocoria duration induced by intermittent blue or red light flashes were calculated. Results: In Experiment 1, the PLR of POAG patients was significantly reduced in all conditions, reflecting the defect in photoreception through rods, cones, and ipRGCs. The variable with the highest area under the receiver operating characteristic curve (AUC) was time to max dilation under ipRGC-weighted stimulus, followed by the constriction amplitude under cone-weighted stimulus and the constriction amplitude response to ipRGC-weighted stimuli. The impaired PLR features were associated with greater visual field loss, thinner retinal nerve fiber layer (RNFL) thickness, and cupping of the optic disk. In Experiment 2, IPA and anisocoria duration induced by intermittent blue or red light flashes were significantly greater in participants with POAG than in controls. IPA and anisocoria duration had good diagnostic value, correlating with the inter-eye asymmetry of visual field loss. Conclusion: We demonstrate that binocular chromatic pupillometry could potentially serve as an objective clinical tool for opportunistic glaucoma diagnosis in community-based or telemedicine-based services. Binocular chromatic pupillometry allows an accurate, objective, and rapid assessment of retinal structural impairment and functional loss in glaucomatous eyes of different severity levels.

Taurine protects R28 cells from hypoxia/re-oxygenation-induced damage via regulation of mitochondrial energy metabolism.

Oxidative-induced damage and hypoxia/re-oxygenation (H/R) injury are common causes of irreversible visual impairment. The goals of this study were to explore the effects of taurine on R28 cells under the two damage models and the underlying mechanisms. Low doses of taurine supplementation promoted cell viability, mitochondrial membrane potential (MMP), SOD levels, ATP contents and attenuated cytotoxicity and intracellular ROS generation of the R28 cells under the two kinds of damage. The expression level of GTPBP3, a mitochondrial-tRNA (mt-tRNA) modification enzyme that catalyzes the taurine involved modification, was decreased under the two damage and taurine could reverse the reduction. After knocking down GTPBP3, the R28 cells become vulnerable to damage. The viability, cytotoxicity, MMP and intracellular ROS level of knockdown cells changed more obviously under the H/R injury than those of control cell. We also found that knockdown of GTPBP3 significantly decreased mitochondrial energy metabolism by measuring the oxidative respiration rate by the Seahorse XFe24 extracellular flux analyzer. The protection of low doses of taurine disappeared on knockdown R28 cells, indicating that GTPBP3 is crucial in the protection mechanisms of taurine. However, the impacts of the reduction of GTPBP3 level can be reversed by relatively high doses of taurine, implying the protection effects of taurine were dose-dependent, and there were more complicated mechanisms remain to be explored. This study explored a new mechanism of the neuroprotective effects of taurine, which depend on the GTPBP3-mediated taurine modification of mt-tRNAs and the promotion of mitochondrial energy metabolism.

Metabolic alterations in the visual pathway of retinitis pigmentosa rats: A longitudinal multimodal magnetic resonance imaging study with histopathological validation.

Because retinitis pigmentosa (RP) has been shown to cause degenerative changes in the entire visual pathway, there is an urgent need to perform longitudinal assessments of RP-induced degeneration and identify imaging protocols to detect this degeneration as early as possible. In this study, we assessed a transgenic rat model of RP by using complementary noninvasive magnetic resonance imaging techniques, namely, proton magnetic resonance spectroscopy (1 H-MRS), to investigate the metabolic changes in RP. Our study demonstrated decreased concentrations and ratios to creatine (Cr) of N-acetylaspartate (NAA), glutamate (Glu), γ-aminobutyric acid (GABA), and taurine (Tau), whereas myo-inositol (Ins) and choline (Cho) were increased in the visual cortex of Royal College of Surgeons (RCS) rats compared with control rats (p < 0.05). Furthermore, with the progression of RP, the concentrations of NAA, Glu, GABA, and Tau, and the ratios of GABA/Cr and Tau/Cr significantly decreased over time, whereas the concentrations of Ins and Cho and the ratio of Ins/Cr significantly increased over time (p < 0.05). In addition, in RCS rats, NAA/Cr decreased significantly from 3 to 4 months postnatal (p < 0.001), and Cho/Cr increased significantly from 4 to 5 months postnatal (p = 0.005). Meanwhile, the 1 H-MRS indicators in 5-month postnatal RCS rats could be confirmed by immunohistochemical staining. In conclusion, with the progression of RP, the metabolic alterations in the visual cortex indicated progressive reprogramming with the decrease of neurons and axons, accompanied by the proliferation of gliocytes.

Green Tea Catechins Attenuate Human Primary Pterygium Cell Survival and Migration Via Modulation of ERK p42/p44 and p38 Pathways.

Pterygium belongs to an ocular surface disease with triangular-shaped hyperplastic growth, characterized by conjunctivalization, inflammation, and connective tissue remodeling. We previously demonstrated neoplastic-like properties of pterygium cells. Green tea catechin, (-)-epigallocatechin gallate (EGCG), has been shown to possess antitumorigenic properties; herein, we aimed to determine the effects of green tea catechins on human primary pterygium cell survival and migration and compared to that on patients' conjunctival cells. Both human primary pterygium and conjunctival cells expressed EGCG receptor, the 67 kDa laminin receptor. Seven-day treatment of green tea extract (Theaphenon E; 16.25 µg/mL) and EGCG (25 µM) attenuated pterygium cell proliferation by 16.78% (p < 0.001) and 24.09% (p < 0.001) respectively, without significantly influencing conjunctival cells. Moreover, green tea extract (16.25 µg/mL) and EGCG (25 µM) treatments also hindered pterygium cell migration by 35.22% (p < 0.001) and 25.20% (p = 0.019), respectively, but not conjunctival cells. Yet, green tea extract and EGCG treatments did not significantly induce pterygium cell apoptosis. Furthermore, green tea extract and EGCG treatments significantly increased the phosphorylation of p38 protein but reduced the phosphorylation of p42/p44 protein in pterygium cells. In summary, this study revealed that green tea extract and EGCG attenuated human primary pterygium cell survival and migration in vitro without damaging conjunctival cells, suggesting a novel potential therapeutic approach for primary pterygium treatment.

Green Tea Extract Ameliorates Ischemia-Induced Retinal Ganglion Cell Degeneration in Rats.

PURPOSE: Oxidative stress induced by reduced blood circulation is a critical pathological damage to retinal ganglion cells (RGCs) in glaucoma. We previously showed that green tea extract (GTE) and its catechin constituents alleviate sodium iodate-induced retinal degeneration in rats. Here, we investigated the therapeutic effect of GTE on ischemia-induced RGC degeneration in rats. METHODS: RGC degeneration was induced by ischemic reperfusion in adult Fischer F344 rats. Green tea extract (Theaphenon E) was intragastrically administered 4 times within 48 hours after ischemia. RGC survival, pupillary light reflex, expressions of cell apoptosis, oxidative stress, and inflammation-related proteins were studied. RESULTS: Ischemic reperfusion significantly induced apoptotic RGCs, RGC loss, and larger constricted pupil area compared to the untreated normal rats. Expressions of activated caspase-3 and caspase-8, Sod2, and inflammation-related proteins as well as p38 phosphorylation were significantly upregulated in the ischemia-injured rats. Compared to the saline-fed ischemic rats, significantly higher number of surviving RGCs, less apoptotic RGCs, and smaller constricted pupil area were observed in the GTE-fed ischemic rats. GTE also reduced the increased protein expressions caused by ischemic injury but enhanced the Jak phosphorylation in the retina. Notably, green tea extract did not affect the survival of RGCs in the uninjured normal rats. CONCLUSIONS: In summary, GTE offers neuroprotection to RGCs under ischemic challenge, suggesting a potential therapeutic strategy for glaucoma and optic neuropathies.

Asiatic Acid Prevents Retinal Ganglion Cell Apoptosis in a Rat Model of Glaucoma.

Asiatic acid (AA), a pentacyclic triterpene derived from the tropical medicinal plant Centella asiatica, has been widely used as an antioxidant and anti-inflammatory agent. Evidence regarding the neuroprotective properties of AA is emerging. However, the protective effects of AA and its mechanism in glaucoma are poorly understood. In the current study, we investigate the neuroprotective effect and mechanism of AA on retinal ganglion cells (RGCs) in a rat model of glaucoma. Elevated intraocular pressure (IOP) was induced in adult rats by injecting microspheres into the anterior chamber. AA was intravitreally injected into glaucomatous rats. RGC densities were analyzed by evaluating surviving RGC number of the retinal flatmounts and retinal sections, and the apoptotic cell number were evaluated by analyzing retinal sections. RGC function was assessed by measuring the photopic negative response (PhNR). Retinal Bcl-2, Bax, and cleaved caspase-3 expression were determined using a Simple Western System, real-time PCR and immunofluorescence staining. AA reduced the loss of RGCs and decreased the apoptotic RGC number. AA exerted neuroprotective effects and ameliorated retinal dysfunction in impaired RGCs in a rat model of glaucoma. AA protected RGCs by upregulating the expression of the antiapoptotic protein Bcl-2 and downregulating the expression of the pro-apoptotic proteins Bax and caspase-3. This study has provided important evidence indicating that AA may be a potential therapeutic agent for glaucoma.

Visual cortex and auditory cortex activation in early binocularly blind macaques: A BOLD-fMRI study using auditory stimuli.

Cross-modal plasticity within the visual and auditory cortices of early binocularly blind macaques is not well studied. In this study, four healthy neonatal macaques were assigned to group A (control group) or group B (binocularly blind group). Sixteen months later, blood oxygenation level-dependent functional imaging (BOLD-fMRI) was conducted to examine the activation in the visual and auditory cortices of each macaque while being tested using pure tones as auditory stimuli. The changes in the BOLD response in the visual and auditory cortices of all macaques were compared with immunofluorescence staining findings. Compared with group A, greater BOLD activity was observed in the bilateral visual cortices of group B, and this effect was particularly obvious in the right visual cortex. In addition, more activated volumes were found in the bilateral auditory cortices of group B than of group A, especially in the right auditory cortex. These findings were consistent with the fact that there were more c-Fos-positive cells in the bilateral visual and auditory cortices of group B compared with group A (p < 0.05). In conclusion, the bilateral visual cortices of binocularly blind macaques can be reorganized to process auditory stimuli after visual deprivation, and this effect is more obvious in the right than the left visual cortex. These results indicate the establishment of cross-modal plasticity within the visual and auditory cortices.

Microbiological Isolates and Antibiotic Susceptibilities: A 10-Year Review of Culture-Proven Endophthalmitis Cases.

PURPOSE: To review the microbiological spectrum and antibiotic sensitivities of the pathogens that cause culture-proven endophthalmitis and to understand the status and trends of antibiotic susceptibility at a public hospital over a 10-year period. METHODS: The data of 577 culture-proven endophthalmitis isolates collected between April 2004 and April 2014 were reviewed retrospectively. The antibiotic sensitivities were determined according to the criteria of the Clinical and Laboratory Standards Institute. The changes in antibiotic susceptibility over the 10 years were subjected to χ2 tests for trends. RESULTS: Among these isolates, 65% were gram-positive organisms (375), 16.6% were gram-negative organisms (96), and 18.4% were fungi (106). The predominant pathogens were Staphylococcal species (Staphylococcus epidermidis in 175, other coagulase-negative Staphylococci in 41, and Staphylococcus aureus in 54 cases), followed by Bacillus cereus isolates. The Aspergillus species was the most frequently isolated fungus, and Pseudomonas aeruginosa was the most frequently isolated gram-negative bacteria. The antibiotic susceptibilities of gram-positive bacteria were as follows: vancomycin, 97.6%; levofloxacin, 85.1%; gentamicin, 78.7%; rifampin, 77.2%; ofloxacin, 77.2%; chloramphenicol, 76.4%; and ciprofloxacin, 73.7%. The antibiotic susceptibilities of gram-negative isolates were as follows: ceftazidime, 50.5%; ciprofloxacin, 82.2%; amikacin, 81.3%; tobramycin, 80.2%; imipenem, 79.7%; and gentamicin, 78%. Over the 10-year study, there were significant changes in the antibiotic susceptibilities to the following five antibiotics: vancomycin, imipenem, penicillin G, amikacin, and trimethoprim-sulfamethoxazole (TMP-SMX). CONCLUSIONS: Vancomycin remains the most appropriate empirical antibiotic for gram-positive bacteria. The susceptibilities of the gram-negative organisms to ciprofloxacin and amikacin were greater than that to ceftazidime. Trends toward increases in the susceptibilities to the following five antibiotics were observed: vancomycin, imipenem, penicillin G, amikacin, and TMP-SMX.

A randomised, parallel-group comparison study of diquafosol ophthalmic solution in patients with dry eye in China and Singapore.

AIMS: To compare the efficacy and safety of 3% diquafosol ophthalmic solution with those of 0.1% sodium hyaluronate ophthalmic solution in patients with dry eye in China and Singapore. METHODS: A total of 497 patients with dry eye (Schirmer's test, 5 mm; fluorescein and RB score, 3 points) from China and Singapore were randomised to receive either diquafosol ophthalmic solution (diquafosol) or sodium hyaluronate ophthalmic solution (HA) at 1:1 ratio. The fluorescein staining scores and rose bengal (RB) subjective symptom scores and tear film breakup time were evaluated before treatment and 2 and 4 weeks after start of treatment. RESULTS: In the diquafosol group, changes in fluorescein and RB scores compared with baseline at week 4 or at the time of discontinuation were -2.1±1.5 and -2.5±2.0, respectively. Compared with the HA group, changes in fluorescein score were non-inferior and changes in RB score were superior (p=0.019). In addition, diquafosol and HA improved tear film breakup time by 1.046±1.797 and 0.832±1.775 s, respectively (no significant intergroup difference). Adverse event onset rates were 16.3% (40 of 246 subjects) and 10.0% (25 of 251 subjects) in the diquafosol group and HA group, respectively, with borderline significant intergroup differences (p=0.046), while adverse drug reaction incidence rates were 12.2% (30 of 246 subjects) and 6.0% (15 of 251 subjects), respectively (p=0.019). Only mild adverse drug reactions (>2%) in the form of eye discharge, itching or irritation were observed. CONCLUSIONS: Diquafosol improved fluorescein staining score in a manner similar to HA, and significantly improved RB score compared with HA. TRIAL REGISTRATION NUMBER: NCT01101984.

[Glial cell and glaucomatous optic neuropathy].

Glaucomatous optic neuropathy is a chronic disease accompanied by visual field loss, cupping of optic nerve head, and apoptosis of retinal ganglion cells (RGCs). The mechanism of glaucomatous optic neuropathy is unknown but glial cells play an important role in glaucomatous optic nerve damage and the repair process. We review the role of glial cells in the remodeling of optic nerve head, apoptosis of RGCs and immune reactions in glaucoma.

Efficacy of acupuncture and identification of tear protein expression changes using iTRAQ quantitative proteomics in rabbits.

PURPOSE: To evaluate the effect of acupuncture on rabbit tear secretion and compare the difference in tear protein expression caused by acupuncture. MATERIALS AND METHODS: Ten male New Zealand White rabbits were enrolled in this study. The following acupoints around the left eye, Extra 1 (Taiyang), BL 2 (Zanzhu) and SJ 23 (Sizhukong), were selected for acupuncture therapy. Each rabbit received 10 acupuncture sessions of 30 min, three times per week. A quantity of 50 µl rabbit tear was collected at the pre- and post-acupuncture stage in every subject, respectively. Total protein content analysis, one-dimensional gel electrophoresis and quantitative proteomics analysis (iTRAQ) were performed and the results were compared. RESULTS: Generally, the tear protein expression after acupuncture was different from that before acupuncture though to some extent they were similar. The time spent collecting rabbit tear after acupuncture was shorter than that before acupuncture. The total protein content in rabbit tear pre- and post-acupuncture was 7.12 µg/µl versus 11.28 µg/µl, respectively. One-dimensional gel electrophoresis showed that tear proteins collected before acupuncture were substantially different than post-acupuncture proteins. In total, twenty-eight tear proteins were identified by iTRAQ. Associated with acupuncture were six up-regulated proteins (tear lipocalin, α-1-antiproteinase, histidine-rich glycoprotein, hemopexin, Vitamin D-binding protein, α-2-HS-glycoprotein) and five down-regulated proteins (Annexin A1, serum amyloid A-3 protein, Helicase-like transcription factor, 15 kDa protein A, protein S100-A9). CONCLUSIONS: The rabbit tear protein expression difference caused by acupuncture indicates that acupuncture not only stimulates lacrimal gland secretion function but also induces the quantitative change of some proteins in rabbit tear, which may support a positive effect of acupuncture in the treatment of dry eye.

Clinical curative effect of acupuncture therapy on xerophthalmia.

This study observes changes in symptoms of xerophthalmia pre- and post-acupuncture therapy and compares the results of the acupuncture therapy (AT) group and the artificial tear control (ATC) group. Parallel comparative studies were carried out on 44 patients with xerophthalmia, who were divided into the AT group (n = 20) and the ATC group (n = 24). A 10-session acupuncture therapy program was performed for the AT group while Dextran 70 was used for the ATC group with each course of treatment lasting 21 day. Examinations were made on the day when a patient was chosen to join the study, 1 hour after completion of treatment, and 3 weeks after stopping treatment. There was no statistically significant difference in terms of the reduction of the symptoms and sign score (SSS) 1 hour after completion of treatment between the AT group and the ATC group. Three weeks after completion of treatment, the reduction of SSS for the AT group was larger than that of the ATC group, with the difference achieving statistical significance. Both acupuncture therapy and artificial tear therapy have an immediate positive effect on the symptoms of xerophthalmia, but acupuncture therapy has a longer continuous effect than that of artificial tears.

Treatment of intractable dry eyes: tear secretion increase and morphological changes of the lacrimal gland of rabbit after acupuncture.

Research on the effect of acupuncture for tear secretion and morphological changes of the lacrimal gland. Acupuncture therapy was given on the rabbits of New Zealand origin. The needles were inserted into the following acupoints around the right eye: Extra 1 (Taiyang), BL 2 ( Zanzhu) and SJ 23 (Sizhukong). The Schirmer Test I (S1T, The Schirmer test is probably the most commonly performed method of measuring aqueous tear production) values pre and post acupuncture therapy were blindly recorded. The lacrimal glands of the normal lacrimal gland group were stained by Hematoxylin and Eosin (HE) for light microscope examination and observed by transmission electron microscope. The S1T value was about sixty percent higher after acupuncture than before. Meanwhile changes also took place in the morphology of lacrimal gland tissu, indicated an active glandular function of synthesis and secretion. Acupuncture can increase lacrimal secretion by stimulating the rabbit lacrimal glandular function of synthesis and secretion.