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
;
Iris Plant
;
Spores, Fungal
;
Mycelium
5.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
;
Eye Movements
;
Humans
;
Lie Detection
;
Pupil
;
Time Factors
6.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
;
Cataract
;
Iris
;
Lenses, Intraocular
;
Phacoemulsification
7.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
;
Humans
;
Intraocular Pressure
;
Male
;
Middle Aged
;
Ofloxacin
;
Pilocarpine
;
Postoperative Period
;
Prednisolone
;
Pupil
;
Pupil Disorders
;
Trabeculectomy
;
Uveitis
8.Homonymous Quadrantanopia Caused by Occipital Lobe Ulegyria
Journal of the Korean Ophthalmological Society 2019;60(2):201-204
PURPOSE: We report a case of homonymous quadrantanopia caused by occipital lobe ulegyria. CASE SUMMARY: A 23-year-female was referred to our clinic because of a visual field defect incidentally discovered during preoperative evaluation for refractive surgery at another clinic. However, she did not report any symptoms. She had no systemic diseases. Visual acuity was 20/20 in both eyes, and the color vision test was normal. Both pupils exhibited normal responses to light and near stimulations. In fundus examinations, the right optic disc was normal and the left contained drusen. Automated perimetry revealed right lower homonymous quadrantanopia with macular sparing. Brain magnetic resonance imaging revealed areas of ulegyria involving the left occipital lobe, consistent with the visual field defect. A follow-up visual field test performed 5 months later yielded the same result. CONCLUSIONS: Neuroimaging should be performed in patients with homonymous visual field defects to determine the location and etiology of the brain lesions. Occipital lobe ulegyria can cause homonymous quadrantanopia in the absence of any neurological problem.
Brain
;
Brain Injuries
;
Color Vision
;
Follow-Up Studies
;
Hemianopsia
;
Humans
;
Magnetic Resonance Imaging
;
Neuroimaging
;
Occipital Lobe
;
Pupil
;
Refractive Surgical Procedures
;
Visual Acuity
;
Visual Field Tests
;
Visual Fields
9.A Report of Two Case of Ocular Toxicity Resulting from Direct or Indirect Bee Venom
Chan Ho LEE ; Chang Hwan LEE ; Moo Hwan CHANG ; Young Seung SEO
Journal of the Korean Ophthalmological Society 2019;60(4):399-405
PURPOSE: To report a patient stung by a bee, who was diagnosed with sterile endopthalmitis and another patient diagnosed with optic neuritis, with decreasing visual acuity, after refined bee venom injection around the orbital tissue. CASE SUMMARY: A 82-year-old female visited our hospital for decreased visual acuity in the right eye and ocular pain due to a bee sting. The bee sting penetrated the sclera into the vitreous. In the anterior segment, severe cornea edema and anterior chamber cells were seen. Using ultrasonography, inflammation was seen around the intravitreal area. After 3 months, intravitreal inflammation regressed but the patient's visual acuity was light perception negative, and corneal opacity, neovascularization, and phthisis bulbi were detected. A 55-year-old male visited our hospital for ocular pain in the right eye and decreasing visual acuity after refined bee venom injection around the orbital tissue. The best-corrected visual acuity in the right eye was 15/100, there was moderate injection on the conjunctiva. A relative afferent pupillary defect, abnormal color vision test results, and a defect in the visual field test were observed. There was no pain during external ocular movement, and other general blood tests, and a brain MRI were normal. Based on these symptoms, methylprednisolone megatherapy was started for treatment of optic neuritis. After treatment, visual acuity of the right eye was 9/10 and all other clinical optic neuritis symptoms regressed. CONCLUSIONS: Based on these two cases, ocular toxicity from bee venom could result from both direct and indirect courses. Treatment using refined bee venom might be harmful, and caution is recommended in its use.
Aged, 80 and over
;
Anterior Chamber
;
Bee Venoms
;
Bees
;
Bites and Stings
;
Brain
;
Color Vision
;
Conjunctiva
;
Cornea
;
Corneal Opacity
;
Edema
;
Female
;
Hematologic Tests
;
Humans
;
Inflammation
;
Magnetic Resonance Imaging
;
Male
;
Methylprednisolone
;
Middle Aged
;
Optic Neuritis
;
Orbit
;
Pupil Disorders
;
Sclera
;
Ultrasonography
;
Visual Acuity
;
Visual Field Tests
10.Transscleral Cyclopexy Using Partial-Thickness Scleral Flap for Repairing Cyclodialysis Cleft: a Case Report
Han Seok PARK ; Shin Young CHOI ; Hyo Ju JANG ; Jae Hong AHN
Journal of the Korean Ophthalmological Society 2019;60(4):393-398
PURPOSE: To report a case of a cyclodialysis cleft that was successfully managed with gonioscopically guided transscleral cyclopexy using partial-thickness scleral flap. CASE SUMMARY: A 44-year-old man complaining of blurred vision in the left eye after blunt trauma was referred to our hospital. The intraocular pressure (IOP) was 4 mmHg and the visual acuity was counting finger. Gonioscopy examination revealed cyclodialysis cleft from 3 to 6 o'clock and fundus examination revealed macular folds. After the failure of conservative medical therapy and laser photocoagulation, gonioscopically guided transscleral cyclopexy using partial-thickness scleral flap was performed. Four months later, the IOP was 18 mmHg, the visual acuity was 0.8, and fundus examination showed the disappearance of the macular folds. CONCLUSIONS: Transscleral cyclopexy using partial-thickness scleral flap is a safe and effective method to treat hypotony maculopathy due to cyclodialysis and to minimize pupil distortion.
Adult
;
Fingers
;
Gonioscopy
;
Humans
;
Intraocular Pressure
;
Light Coagulation
;
Methods
;
Pupil
;
Visual Acuity

Result Analysis
Print
Save
E-mail