1.Modeling and finite element analysis of human trabecular meshwork outflow pathways.
Shiya BAO ; Qing SUN ; Si CHEN ; Xinyu CHEN ; Xiang PENG ; Jing ZHANG
Journal of Biomedical Engineering 2025;42(3):585-591
Glaucoma is the leading cause of irreversible blindness worldwide, with its primary risk factor arising from elevated intraocular pressure (IOP) due to an imbalance between aqueous humor production and outflow. This study aims to establish quantitative correlations among IOP, iris mechanical properties, channel microstructures, and aqueous humor dynamics through three-dimensional modeling and finite element analysis, overcoming the limitations of conventional experimental techniques in studying aqueous flow within the trabecular meshwork (TM) outflow pathway. A three-dimensional fluid-structure interaction (FSI) model incorporating the layered TM structure, Schlemm's canal (SC), iris, and other anterior segment tissues was developed based on human ocular anatomy. FSI simulations were performed to quantify the effects of IOP variations and iris Young's modulus on tissue morphology and aqueous humor dynamics parameters. The computational results demonstrated that axial iris deformation showed significant correlations with IOP and iris Young's modulus. Although elevated IOP exhibited minimal effects on hydrodynamic parameters in the anterior and posterior chambers, it markedly suppressed aqueous flow velocity in the TM region. Additionally, wall shear stress in SC and collector channels displayed high sensitivity to IOP variations. These findings reveal that the tissue mechanics-FSI mechanism modulates outflow resistance by regulating aqueous humor dynamics, offering valuable references for developing clinical therapies targeting IOP reduction in glaucoma management.
Humans
;
Trabecular Meshwork/anatomy & histology*
;
Finite Element Analysis
;
Aqueous Humor/metabolism*
;
Intraocular Pressure/physiology*
;
Glaucoma/physiopathology*
;
Iris/anatomy & histology*
;
Computer Simulation
;
Models, Biological
2.Pupillometry reveals hyper-arousal in response to auditory stimuli in autistic children.
Ci SONG ; Runsheng MA ; Wei NI ; Xinyue PENG ; Xue LI ; Ruoxi SHI ; Yuanping ZHANG ; Li YI
Journal of Zhejiang University. Science. B 2024;25(11):996-1008
Atypical sensory responsivity is widely reported in autistic individuals and is related to elevated functional difficulties. Dynamically, altered initial responses and/or habituation rates could underlie their atypical averaged responses to repeated sensory stimuli. In this study we aimed to measure the arousal level in response to different types of auditory stimuli and the dynamic change of atypical arousal level using pupillometry in autistic children. In Experiment 1, 43 autistic children and 49 neurotypical (NT) children were asked to passively listen to a mild sound and an aversive sound repeatedly. In Experiment 2, 39 autistic children and 44 NT children who went through Experiment 1 listened to a gradually emerging non-startling sound and a suddenly emerging startling sound in a random order. We found that the autistic group showed hyper-arousal in response to the aversive sound and the startling sound as reflected by their larger change in pupil area. In comparison, these autistic children demonstrated normal arousal in response to the mild sound and the non-startling sound. Dynamically, the autistic group had a larger peak pupil area change than the NT group in the first trial and a normal habituation rate to the aversive sound. In summary, our results suggest hyper-arousal to aversive and startling stimuli and the role of larger initial responses in hyper-arousal in autism. Minimizing aversive and startling sensory stimuli or gradually increasing the volume of aversive auditory stimuli to allow autistic children to adapt using the principle of habituation is recommended to reduce the arousal level and problematic behaviors of autistic children.
Humans
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Male
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Child
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Female
;
Acoustic Stimulation
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Autistic Disorder/physiopathology*
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Arousal/physiology*
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Pupil/physiology*
;
Habituation, Psychophysiologic/physiology*
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Auditory Perception
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Child, Preschool
3.Identification, biological characterization, and fungicide screening of pathogens causing leaf spot of Belamcanda chinensis.
Ya-Wen YANG ; Qiao-Huan CHEN ; Jia ZHOU ; Bi-Sheng HUANG ; Yu-Huan MIAO ; Da-Hui LIU
China Journal of Chinese Materia Medica 2022;47(22):6042-6049
The leaf spot of Belamcanda chinensis often appears in May to June and spreads rapidly during the flowering stage(July to September) in the cultivation fields, seriously affecting the yield and quality of B. chinensis. To identify and characterize the pathogens of the leaf spot, we isolated two species of Alternaria, identified them according to Koch's postulates, and tested their pathogenicity and biological characteristics. Furthermore, we determined the inhibitory effects of 6 chemical fungicides, 1 plant fungicide, and 3 microbial fungicides on the pathogens by using mycelial growth rate and plate confrontation method to select the appropriate control agents. The results showed that the two pathogens causing B. chinensis leaf spot were Alternaria tenuissima and A. alternata. The conidia of A. tenuissima often formed long chains with no or a few branches, while those of A. alternata often formed short branched chains. The optimum growth temperature of both A. tenuissima and A. alternata was 25 ℃. The two pathogens grew well in alkaline environment. The indoor fungicide screening experiments showed that 40% flusilazole had good inhibitory effects on the two pathogens, with the EC_(50) values of 12.42 mg·L~(-1) and 12.78 mg·L~(-1) for A. tenuissima and A. alternata, respectively. The results of this study provide a theoretical basis for the subsequent theoretical research and field control of B. chinensis leaf spot.
Fungicides, Industrial/pharmacology*
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Research
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Iris Plant
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Spores, Fungal
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Mycelium
5.Anterior Chamber and Lens Position before and after Phacoemulsification According to Axial Length
Suk Hoon JUNG ; Seonjoo KIM ; So Hyang CHUNG
Journal of the Korean Ophthalmological Society 2020;61(1):17-26
PURPOSE: In this study, we evaluated changes in the anterior chamber structure and lens position before and after phacoemulsification in eyes grouped by axial length (AL).METHODS: This study included 65 eyes (16 short eyes [AL < 22.5 mm], 33 normal eyes [22.5 mm < AL < 25.0 mm], and 16 long eyes [AL > 25.5 mm]) that underwent cataract surgery. Pre- and postoperative anterior chamber depth (ACD) was measured using Pentacam® and IOL Master®,. In addition, we evaluated the anterior chamber angle (ACA), anterior chamber volume (ACV), epithelium-iris distance, and iris-lens (intraocular lens [IOL]) distance.RESULTS: The change in ACD was significantly smaller in long eyes (Pentacam®,, p = 0.000; IOL Master®,, p = 0.001). The change in ACA was significantly larger in short eyes (p = 0.000), and the change in ACV was significantly smaller in long eyes (p = 0.000). The change in the epithelium–iris distance was significantly smaller in long eyes (p = 0.000), and the change in the iris-lens (IOL) distance was significantly smaller in short eyes (p = 0.000).CONCLUSIONS: In short eyes, changes in ACD, ACA, and ACV were found to be larger than those of other groups as the iris moved backward. In long eyes, greater backward movement of the IOL was observed. Therefore, the appropriate IOL power should be chosen, considering the postoperative position of the IOL during cataract surgery of short and long eyes.
Anterior Chamber
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Cataract
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Iris
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Lenses, Intraocular
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Phacoemulsification
6.Urrets-Zavalia Syndrome Following Trabeculectomy
Gi Seok PARK ; Yeo Kyoung WON ; Kyoung Nam KIM ; Yeon Hee LEE ; Chang sik KIM
Journal of the Korean Ophthalmological Society 2020;61(2):221-225
PURPOSE: We report a case of Urrets-Zavalia syndrome with a fixed dilated pupil after an uneventful trabeculectomy.CASE SUMMARY: Trabeculectomy was performed on a 51-year-old male who had a history of recurrent uveitis in the left eye, with uncontrolled intraocular pressure despite maximally-tolerated medial therapy. There was no unexpected event during surgery. Topical 1% atropine was used for only 2 days after surgery. In the early postoperative period, 1% prednisolone and 0.3% ofloxacin were given four times a day, then gradually reduced. One month later, only 1% prednisolone was given once a day. Intraocular pressure in his left eye was well controlled from 8–14 mmHg after surgery. One month after surgery, the pupils remained dilated. There was no reaction to topical 2% pilocarpine and no relative afferent pupillary defect or posterior synechia.CONCLUSIONS: Our case, although rare, suggests that Urrets-Zavalia syndrome should be considered in patients with well-controlled intraocular pressure after uneventful trabeculectomy.
Atropine
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Humans
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Intraocular Pressure
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Male
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Middle Aged
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Ofloxacin
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Pilocarpine
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Postoperative Period
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Prednisolone
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Pupil
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Pupil Disorders
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Trabeculectomy
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Uveitis
7.Application of Eye Tracker in Lie Detection.
Fen Fen GE ; Xiao Qing YANG ; Yu Xing CHEN ; Hao Lan HUANG ; Xia Can SHEN ; Yan LI ; Jun Mei HU
Journal of Forensic Medicine 2020;36(2):229-232
Objective To investigate the application value of eye tracking in lie detection. Methods The 40 subjects were randomly divided into two groups. The pupil diameter, fixation duration, points of fixation and blink frequency of the subjects in the experimental group in observing target stimulation and non-target stimulation were recorded with eye tracker after they accomplished the mock crime. The eye movement parameters of subjects in the control group were directly collected. The differences in eye movement parameters of the experimental group and the control group in observing target stimulation and non-target stimulation were analyzed by t-test. Pearson coefficient analysis of correlation between eye movement parameters that had differences was conducted. The effectiveness of eye movement parameters to distinguish between the experimental group and the control group was calculated by the receiver operator characteristic (ROC) curve. Results Participants from the experimental group had shorter average pupil diameter, longer average fixation duration and fewer fixation points (P<0.05), but the differences in blink frequency had no statistical significance. The differences in the above indicators of the control group in observing target stimulation and non-target stimulation had no statistical significance. The average fixation duration showed a negative correlation with fixation points (r=-0.255, P<0.05); the average fixation duration showed a negative correlation with average pupil diameter (r=-0.218, P<0.05); the fixation points showed a positive correlation with average pupil diameter (r=0.09, P<0.05). The area under the curve of average pupil diameter, average fixation duration and fixation points was 0.603, 0.621 and 0.580, respectively. Conclusion The average pupil diameter, average fixation duration and fixation points obtained by the eye tracker under laboratory conditions can be used to detect lies.
Algorithms
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Eye Movements
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Humans
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Lie Detection
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Pupil
;
Time Factors
8.Exploring Brow Position Changes with Age in Koreans
Korean Journal of Ophthalmology 2019;33(1):91-94
PURPOSE: Several studies have described age-associated brow drooping in Westerners. However, there are few studies that address brow drooping in the Asian population, and especially in the Korean population. Therefore, we studied brow position changes with age in Korean individuals. METHODS: A total of 300 adults older than 18 years were enrolled. The ImageJ program was used to analyze digital photos of the patients by measuring the following parameters: marginal reflex distance-1, brow-to-pupil distance, nasal ala-lateral brow distance, lateral brow plumb line, and the angle formed by the line from the mid pupil to the midline of the brow and a line from the midline of the brow to the lateral brow. We divided the patients into three groups (18 to 40, 41 to 60, older than 61) and compared them using the ANOVA test. RESULTS: Group A included 100 patients between 18 and 40 years of age. Group B included 100 patients between 41 and 60 years of age. Group C included 100 patients older than 61 years. There were significant differences between groups A and C and between groups B and C with regard to marginal reflex distance-1, brow-to-pupil distance and the angle. Lateral brow plumb line showed significant difference only between groups A and B. Nasal ala-lateral brow distance was not significantly different across the three groups. CONCLUSIONS: We sought to describe the physiologic facial changes that occur in Korean individuals. We also hoped to establish guidelines for ptosis corrective surgery. We used various parameters to characterize the aging process in Asians. Our data demonstrated that, like Westerners, Koreans experience lateral brow drooping with age; however, this change was only significant in the group aged >61 years.
Adult
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Aging
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Asian Continental Ancestry Group
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Hope
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Humans
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Pupil
;
Reflex
9.Analysis of Positional Relationships of Various Centers in Cataract Surgery
Woo Keun SONG ; Jin Ah LEE ; Jae Yong KIM ; Myoung Joon KIM ; Hungwon TCHAH
Korean Journal of Ophthalmology 2019;33(1):70-81
PURPOSE: To analyze the positional relationships of various centers in patients undergoing femtosecond laser-assisted cataract surgery (FLACS). METHODS: The locations of the pupil center (PC), limbal center (LC) and lens center were analyzed in each patient using optical coherence tomography during FLACS in 35 eyes of 35 patients. Using the preoperative corneal aberrometry device, angle kappa and the location of the visual axis (VA) were calculated. After acquiring the relative horizontal and vertical coordinates of each center, the distance and location among each center were compared. The relative location and distance of each center were statistically evaluated. RESULTS: The distance from the PC to the lens center was 0.147 ± 0.103 mm, that from the LC to the lens center was 0.205 ± 0.104 mm, and that from the VA to the lens center was 0.296 ± 0.198 mm. The distance from the PC to the VA was 0.283 ± 0.161 mm, that from the LC to the VA was 0.362 ± 0.153 mm, and that from the lens center to the VA was 0.296 ± 0.198 mm. Among the various centers, the PC was the closest to the lens center, whereas the LC and VA were the farthest. Based on the location of the lens center, the PC, LC, and VA exhibited differences in the X and Y coordinate positions (vertical p = 0.004, horizontal p < 0.001). Among them, the LC was significantly inferior and temporal compared to the PC (vertical p = 0.026, horizontal p = 0.023). Based on the location of the VA, the respective locations of the PC, LC and lens center in two dimensions did not significantly differ (vertical p = 0.310, horizontal p = 0.926). CONCLUSIONS: This study demonstrated the positional and locational relationships between the centers regarding FLACS. The locations of the PC, LC, and VA were different from the lens center with the PC being the closest. Surgeons should be aware of these positional relationships, especially in FLACS.
Aberrometry
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Cataract
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Humans
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Pupil
;
Surgeons
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Tomography, Optical Coherence
10.Objective Verification of Physiologic Changes during Accommodation under Binocular, Monocular, and Pinhole Conditions.
Honghyun PARK ; In Ki PARK ; Jae Ho SHIN ; Yeoun Sook CHUN
Journal of Korean Medical Science 2019;34(4):e32-
BACKGROUND: To objectively investigate accommodative response to various refractive stimuli in subjects with normal accommodation. METHODS: This prospective, non-randomized clinical trial included 64 eyes of 32 subjects with a mean spherical equivalent −1.4 diopters (D). We evaluated changes in accommodative power, pupil diameter, astigmatic value, and axis when visual stimuli were applied to binocular, monocular (dominant eye, non-dominant eye, ipsilateral, and contralateral), and pinhole conditions. Visual stimuli were given at 0.25 D (4 m), 2 D (50 cm), 3 D (33 cm), and 4 D (25 cm) and accommodative response was evaluated using open view binocular autorefractor/keratometer. RESULTS: The accommodative response to binocular stimulus was 90.9% of the actual refractive stimulus, while that of the monocular stimulus was 84.6%. The binocular stimulus induced a smaller pupil diameter than did the monocular stimulus. There was no difference in accommodative response between the dominant eye and non-dominant eye or between ipsilateral and contralateral stimuli. As the refractive stimuli became stronger, the absolute astigmatic value increased and the direction of the astigmatism axis became more horizontal. Pinhole glasses required 10%–15% less accommodative power compared with the monocular condition. CONCLUSION: Binocular stimuli enable more precise and effective accommodation than do monocular stimuli. Accommodative response is composed of 90% true accommodation and 10% pseudo-accommodation, and the refractive stimulus in one eye affects the contralateral eye to the same extent. This should be taken into account when developing guidelines for wearing smart glasses while driving, as visual stimulation is applied to only one eye, but far distance attention is constantly needed. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03557346
Astigmatism
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Eyeglasses
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Glass
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Non-Randomized Controlled Trials as Topic
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Photic Stimulation
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Prospective Studies
;
Pupil
;
Telescopes*

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