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.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
3.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
4.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
;
Aphakia
;
Astigmatism
;
Corneal Topography
;
Endothelial Cells
;
Hoof and Claw
;
Humans
;
Intraocular Pressure
;
Iris
;
Lenses, Intraocular
;
Refractometry
;
Retrospective Studies
;
Slit Lamp
;
Visual Acuity
5.Iridocorneal Endothelial Syndrome with Features of Posterior Polymorphous Corneal Dystrophy
Journal of the Korean Ophthalmological Society 2019;60(9):909-914
PURPOSE: To report a case of iridocorneal endothelial syndrome, which overlapped with some of the features of posterior polymorphous corneal dystrophy. CASE SUMMARY: A 61-year-old female presented with tearing pain and blurred vision in her left eye, which was aggravated in the morning. The symptom started approximately 1 year prior to her visit. At the initial visit, the visual acuities were 1.0 in both eyes and the intraocular pressures were normal. On slit-lamp examination, a single pair of horizontal parallel lines was observed at the central corneal endothelial layer in the right eye. In contrast, multiple pairs of oblique parallel lines were observed in the left eye. The lines of the lesions were more prominent and wavier in the left eye than those of the right eye. The overlying cornea was clear, and the corneal thicknesses were in the normal range in both eyes. Using a gonioscopic examination, localized peripheral anterior synechiae were observed only in the left eye. The pupil and iris were normal in both eyes. On specular microscopic examination, the corneal endothelial cell size in the right eye increased and the corneal endothelial density decreased to 668 cells/mm². In the left eye, multiple abnormal endothelial cells with dark-light reversal were observed. In conclusion, the patient was subsequently diagnosed with iridocorneal syndrome, rather than posterior polymorphous corneal dystrophy. CONCLUSIONS: Posterior polymorphous corneal dystrophy and iridocorneal endothelial syndrome may present with many similarities. Therefore, in cases of uncertain diagnosis, an understanding of the clinical features is important for proper diagnosis.
Cornea
;
Diagnosis
;
Endothelial Cells
;
Female
;
Humans
;
Intraocular Pressure
;
Iridocorneal Endothelial Syndrome
;
Iris
;
Middle Aged
;
Pupil
;
Reference Values
;
Tears
;
Visual Acuity
6.Classification of Iris Colors and Patterns in Koreans.
HyeJung JANG ; JinSook YOON ; Yoon Jung KIM ; YungKyung PARK
Healthcare Informatics Research 2018;24(3):227-235
OBJECTIVES: The iris is the part of the eye that is colored, and it is an important feature in making an artificial eye. To address the lack of information about the brown Korean irises, we classified the colors and patterns of the irises of 100 Korean eyes. METHODS: The iris colors were extracted from 100 different digital photographs of each eye using K-mean clustering image analysis. The RGB data of the extracted colors were converted to CIELAB color space data and analyzed to determine the representative color of the iris in each photograph. The color differences were calculated to form groups of similar colors by matching the 100 samples into several groups with minimum color differences among them. The average hue value for each group was calculated, and the corresponding representative color was selected from 2 to 3 colors in one group. RESULTS: The iris colors were classified into seven brown color groups with 2 to 3 colors in each group. The coloration of Koreans' eyes appears to vary in a similar hue with differences in chroma and lightness. In addition, the iris patterns were classified into three basic patterns, namely, crown, sunshine, and flower, as well as three complex patterns that are mixtures of two basic patterns. CONCLUSIONS: We classified Korean iris colors and patterns for application in the design of artificial eyes.
Asian Continental Ancestry Group
;
Classification*
;
Crowns
;
Eye, Artificial
;
Flowers
;
Humans
;
Iris*
;
Sunlight
7.Mycobacterium avium Complex Infection-Related Immune Reconstitution Inflammatory Syndrome Mimicking Lymphoma in an Human Immunodeficiency Virus-Infected Patient.
Sungmin SOHN ; Hye Jin SHI ; Sung Ho WANG ; Sang Ki LEE ; So Yeon PARK ; Jin Seo LEE ; Joong Sik EOM
Infection and Chemotherapy 2018;50(4):350-356
In acquired immunodeficiency syndrome (AIDS) patients, immune reconstitution inflammatory syndrome (IRIS) due to Mycobacterium avium complex (MAC) infection is one of the most difficult IRIS types to manage. We report an unusual case of MAC-associated IRIS. At first the patient was diagnosed human immunodeficiency virus (HIV) infection after he was admitted with pneumocystis pneumonia. After starting antiretroviral therapy he presented unmasked IRIS with MAC infection. Next, he was hospitalized with continuous loose stools and new-onset fever. Investigation included computed tomography (CT), which showed homogeneous enhancement and enlargement of the lymph nodes (LN), elevation of ferritin (>1,650 ng/mL) and lactate dehydrogenase (306 IU/L) levels, and F- fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scan, which showed increased FDG uptake. These findings were highly indicative of lymphoma. We performed laparoscopic biopsy of the mesenteric LN, and the biopsy culture grew MAC. So we made a diagnosis of MAC-associated. Therefore, IRIS must be considered as a possible diagnosis when AIDS patients develop new symptoms or exhibit exacerbations of existing symptoms. Furthermore the biopsies should be conducted.
Acquired Immunodeficiency Syndrome
;
Biopsy
;
Diagnosis
;
Electrons
;
Ferritins
;
Fever
;
HIV
;
Humans*
;
Immune Reconstitution Inflammatory Syndrome*
;
Iris
;
L-Lactate Dehydrogenase
;
Lymph Nodes
;
Lymphoma*
;
Mycobacterium avium Complex*
;
Mycobacterium avium*
;
Mycobacterium*
;
Pneumonia, Pneumocystis
8.Mycobacterium avium Complex Infection-Related Immune Reconstitution Inflammatory Syndrome Mimicking Lymphoma in an Human Immunodeficiency Virus-Infected Patient.
Sungmin SOHN ; Hye Jin SHI ; Sung Ho WANG ; Sang Ki LEE ; So Yeon PARK ; Jin Seo LEE ; Joong Sik EOM
Infection and Chemotherapy 2018;50(4):350-356
In acquired immunodeficiency syndrome (AIDS) patients, immune reconstitution inflammatory syndrome (IRIS) due to Mycobacterium avium complex (MAC) infection is one of the most difficult IRIS types to manage. We report an unusual case of MAC-associated IRIS. At first the patient was diagnosed human immunodeficiency virus (HIV) infection after he was admitted with pneumocystis pneumonia. After starting antiretroviral therapy he presented unmasked IRIS with MAC infection. Next, he was hospitalized with continuous loose stools and new-onset fever. Investigation included computed tomography (CT), which showed homogeneous enhancement and enlargement of the lymph nodes (LN), elevation of ferritin (>1,650 ng/mL) and lactate dehydrogenase (306 IU/L) levels, and F- fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scan, which showed increased FDG uptake. These findings were highly indicative of lymphoma. We performed laparoscopic biopsy of the mesenteric LN, and the biopsy culture grew MAC. So we made a diagnosis of MAC-associated. Therefore, IRIS must be considered as a possible diagnosis when AIDS patients develop new symptoms or exhibit exacerbations of existing symptoms. Furthermore the biopsies should be conducted.
Acquired Immunodeficiency Syndrome
;
Biopsy
;
Diagnosis
;
Electrons
;
Ferritins
;
Fever
;
HIV
;
Humans*
;
Immune Reconstitution Inflammatory Syndrome*
;
Iris
;
L-Lactate Dehydrogenase
;
Lymph Nodes
;
Lymphoma*
;
Mycobacterium avium Complex*
;
Mycobacterium avium*
;
Mycobacterium*
;
Pneumonia, Pneumocystis
9.Comparison of Anterior Segment Features between Groups with or without Glaucoma in Pseudoexfoliation Syndrome
Journal of the Korean Ophthalmological Society 2018;59(11):1049-1055
PURPOSE: To investigate the factors associated with glaucoma in patients with pseudoexfoliation syndrome by comparing features of the anterior segments and ocular biometry according to the presence or absence of open-angle glaucoma in pseudoexfoliation syndrome. METHODS: We analyzed 96 patients (115 eyes) diagnosed as having pseudoexfoliation syndrome in this study. The patients were divided into two groups of simple pseudoexfoliation syndrome (64 patients, 76 eyes) and pseudoexfoliation glaucoma (32 patients, 39 eyes). We compared the age, sex, underlying disease, location of pseudoexfoliative material, iris change, degree of nuclear cataract, pupil dilatation, corneal endothelial cell counts, central corneal thickness, anterior chamber depth, axial length, corneal curvature, and intraocular pressure (IOP). RESULTS: There were no significant differences between the two groups in terms of age (p = 0.694), sex (p = 0.161), diabetes (p = 0.440), hypertension (p = 0.238), pseudoexfoliative material observed in anterior capsule (p = 0.700), pupillary margin (p = 0.210), iris depigmentation (p = 0.526), pupillary ruff loss (p = 0.708), degree of nuclear cataract (p = 0.617), pupil dilatation (p = 0.526), central corneal thickness (p = 0.097), anterior chamber depth (p = 0.283), axial length (p = 0.095), or horizontal and vertical corneal curvature (p = 0.066 and 0.306, respectively). In pseudoexfoliation glaucoma, significantly higher IOP (p = 0.026), a high frequency of membrane formation (p = 0.047), and decreased corneal endothelial cell counts (p = 0.048) were observed. CONCLUSIONS: Pseudoexfoliation syndrome with open-angle glaucoma was shown to be associated with high IOP, decreased corneal endothelial cell counts, and a high frequency of membrane formation. Therefore, when such changes are observed in pseudoexfoliation syndrome patients, a higher risk of open-angle glaucoma should be recognized, and careful attentionis required accordingly.
Anterior Chamber
;
Biometry
;
Cataract
;
Dilatation
;
Endothelial Cells
;
Exfoliation Syndrome
;
Glaucoma
;
Glaucoma, Open-Angle
;
Humans
;
Hypertension
;
Intraocular Pressure
;
Iris
;
Membranes
;
Pupil
10.A Case of Isolated Traumatic Aniridia in a Pseudophakic Eye
Mi Young KWON ; Hye Jin HONG ; Dae Jin PARK
Journal of the Korean Ophthalmological Society 2018;59(12):1185-1189
PURPOSE: We report a rare case of isolated traumatic aniridia in a pseudophakic eye. CASE SUMMARY: A 69-year-old female came to our emergency department complaining of right eye pain and visual disturbance after trauma due to fall on the stairs. Five years earlier she had undergone an uncomplicated right sutureless phacoemulsification cataract extraction through a 2.2 mm temporal clear corneal incision, followed by insertion of a folding intracapsular intraocular lens. Total iris expulsion occurred through the cataract incision without extension of the wound or disruption of the posterior capsule or intraocular lens. CONCLUSIONS: We report a rare case of isolated traumatic aniridia in a pseudophakic eye, which has not been reported in the Republic of Korea.
Aged
;
Aniridia
;
Cataract
;
Cataract Extraction
;
Emergency Service, Hospital
;
Eye Pain
;
Female
;
Humans
;
Iris
;
Lenses, Intraocular
;
Phacoemulsification
;
Republic of Korea
;
Wounds and Injuries

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