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
;
Male
;
Child
;
Female
;
Acoustic Stimulation
;
Autistic Disorder/physiopathology*
;
Arousal/physiology*
;
Pupil/physiology*
;
Habituation, Psychophysiologic/physiology*
;
Auditory Perception
;
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*
;
Research
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Iris Plant
;
Spores, Fungal
;
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
;
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.Visual Loss with Ophthalmoplegia after Prone Position Spinal Surgery
Mi Hwa PARK ; Ji Hye KIM ; Ji Myong YOO
Journal of the Korean Ophthalmological Society 2019;60(7):712-717
PURPOSE: We report a case of acute visual loss with ophthalmoplegia after prone position spinal surgery who had blood supply dependence on collateral circulation due to occlusion of the Internal carotid artery. CASE SUMMARY: A 74-year-old man was referred to the department of ophthalmology for acute visual loss and ophthalmoplegia after lumbar spine surgery performed in prone position. On the initial visit, his right visual acuity was 0.8 and the left visual acuity was negative light perception. Intraocular pressure was normal. There was a relative afferent pupillary defect and ophthalmoplegia of all directions in the left eye. Because of the ptosis of the upper eyelid in the left eye, it was impossible to tune the eye voluntarily. The cherry red spot and pale retina were observed on the fundus examination. On brain magnetic resonance imaging angiography, we found complete obstruction of the left internal carotid artery. He had intravenous injection of 1 g methylprednisolone for 3 days, and discharged with per oral medicine. After 1 month of treatment, the ophthalmoplegia was slightly improved, but visual acuity was not recovered. CONCLUSIONS: In this case, unlike previous reports, acute visual loss and ophthalmoplegia occurred after spinal surgery the patient who had collateral circulation for ocular blood supply because of complete obstruction of the left internal carotid artery. This report highlights the importance of being aware of the anatomical variant in possible complications of external ocular compression after non-ocular surgery.
Aged
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Angiography
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Brain
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Carotid Artery, Internal
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Collateral Circulation
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Eyelids
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Humans
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Injections, Intravenous
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Intraocular Pressure
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Magnetic Resonance Imaging
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Methylprednisolone
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Ophthalmology
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Ophthalmoplegia
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Oral Medicine
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Prone Position
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Pupil Disorders
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Retina
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Retinal Artery Occlusion
;
Spine
;
Visual Acuity
9.Frosted Branch Angiitis Associated with Epstein-Barr Virus Infection
Journal of the Korean Ophthalmological Society 2019;60(7):706-711
PURPOSE: To report a case of frosted branch angiitis (FBA) associated with Epstein-Barr virus (EBV) infection in a child. CASE SUMMARY: A 7-year-old boy presented with bilateral blurred vision. On ophthalmic examination, his best-corrected visual acuity was 20/25 in the right eye and 20/32 in the left eye. The pupils were equal, round, and reactive to light without a relative afferent pupillary defect. He had normal color vision in both eyes. Slit-lamp examination revealed no abnormalities in the anterior parts of the eyes. Fundoscopic examination revealed prominent white sheathing retinal vasculitis predominantly on the veins in all quadrants, as well as macular edema and irregular foveal reflex in both eyes. Fluorescein angiography showed normal blood flow, but late diffuse staining and leakage of the affected vessels. Spectral domain optical coherence tomography (SD-OCT) showed thickening of the vessel walls, swelling due to hyperreflective material, and hyperreflective retinal depositions. Serological tests and the serum polymerase chain reaction for EBV were positive. A diagnosis of FBA associated with EBV was made. He was treated with systemic acyclovir and steroids. The response was rapid, with improvement in visual acuity to 20/20 in both eyes by day 3. After 7 weeks, all clinical signs resolved and SD-OCT examination showed normal vessel wall thickness and the absence of hyperreflective depositions. CONCLUSIONS: EBV may present with FBA even in the absence of a systemic sign of primary EBV infection. Thus, EBV should be considered as the etiology of FBA.
Acyclovir
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Child
;
Color Vision
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Diagnosis
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Epstein-Barr Virus Infections
;
Fluorescein Angiography
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Herpesvirus 4, Human
;
Humans
;
Macular Edema
;
Male
;
Polymerase Chain Reaction
;
Pupil
;
Pupil Disorders
;
Reflex
;
Retinal Vasculitis
;
Retinaldehyde
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Serologic Tests
;
Steroids
;
Tomography, Optical Coherence
;
Vasculitis
;
Veins
;
Visual Acuity
10.Scleral Fixation of Intraocular Lens and Retropupillary Fixation of Iris Claw Lens for Aphakic Eyes
Joo Young KIM ; Chang Hyun PARK ; Woong Joo WHANG ; Kyung Sun NA ; Hyun Seung KIM
Journal of the Korean Ophthalmological Society 2019;60(7):643-653
PURPOSE: To compare the efficacy and complications of scleral fixation of posterior chamber intraocular lens (IOL) and retropupillary fixation of iris claw IOL for dislocated IOL or aphakia without sufficient capsular support. METHODS: This retrospective study was comprised of 17 eyes of 16 patients undergoing scleral fixation and 14 eyes of 13 patients undergoing retropupillary fixation from August 2013 to June 2018. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp examination, corneal topography, refractive indices, corneal curvatures, corneal endothelial cell density, and complications of both groups were examined preoperatively and 1 day, 1 week, 1 month, 2 months, and 6 months postoperatively. RESULTS: Six months after the operation, UCVA and BCVA improved in both groups; however, there were no significant differences between the two groups (UCVA, p = 0.162; BCVA, p = 0.418). IOP was temporarily higher in the scleral fixation group at one day postoperatively (p = 0.023). The mean absolute prediction error was smaller in the retropupillary iris fixation group at 6 months postoperatively (p = 0.034). Postoperative total astigmatism, corneal astigmatism, and corneal endothelial cell density were not significantly different between the two groups. CONCLUSIONS: The retropupillary iris fixation group did not show significant improvement in visual acuity compared with the scleral fixation group. However, the retropupillary iris fixation group provided better mean absolute prediction error and a low risk of postoperative increase in IOP compared with the scleral fixation group. Retropupillary fixation of iris claw IOL is a promising option for scleral fixation of posterior chamber IOL for dislocated IOL or aphakia without sufficient capsular support.
Animals
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Aphakia
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Astigmatism
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Corneal Topography
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Endothelial Cells
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Hoof and Claw
;
Humans
;
Intraocular Pressure
;
Iris
;
Lenses, Intraocular
;
Refractometry
;
Retrospective Studies
;
Slit Lamp
;
Visual Acuity

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