1.Measurement and characterization of retinal vascular morphology parameters based on artificial intelligence automated analysis technology
Xuhan SHI ; Li DONG ; Lei SHAO ; Saiguang LING ; Zhou DONG ; Ying NIU ; Ruiheng ZHANG ; Wenda ZHOU ; Wenbin WEI
Chinese Journal of Experimental Ophthalmology 2024;42(1):38-46
Objective:To analyze retinal vascular parameters and distribution characteristics in Chinese population via the fully automated quantitative measurement of retinal vascular morphological parameters based on artificial intelligence technology.Methods:A cross-sectional study was performed.A total of 1 842 patients without fundus diseases who visited Beijing Tongren Hospital from January 2011 to December 2021 were included.Standardized questionnaires, blood draws and ophthalmologic examinations of enrolled subjects were conducted.Color fundus photographs centered on the optic disk of one eye of patients were collected, and a deep learning-based semantic segmentation network ResNet101-Unet was used to construct a vascular segmentation model for fully automated quantitative measurement of retinal vascular parameters.The main measurement indexes included retinal vascular branching angle, vascular fractal dimension, average vascular caliber, and average vascular tortuosity.To compare different retinal parameters between sexes, the correlation between the above parameters and ocular factors such as best corrected visual acuity, intraocular pressure, and axial length, as well as systemic factors such as sex, age, hypertension, diabetes mellitus, and cardiovascular disease was analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.20001220). Written informed consent was obtained from each subject.Results:The model established in this study achieved an accuracy over 0.95 for both vascular and optic disk segmentation.The vascular branching angle, vascular fractal dimension, average vascular caliber, and average vascular tortuosity were (51.023±11.623)°, 1.573(1.542, 1.592), 64.124(60.814, 69.053)μm, (0.001 062±0.000 165)°, respectively.Compared with females, males had larger vascular branching angle, smaller average vascular caliber and smaller vascular tortuosity, and the differences were statistically significant (all at P<0.05). The average vascular caliber increased by 1.142 μm in people with cardiovascular disease compared to people without cardiovascular disease ( B=1.142, P=0.029, 95% CI: 0.116-2.167). The average vascular tortuosity was positively correlated with hypertension ( B=3.053×10 -5, P=0.002, 95% CI: 1.167×10 -5-4.934×10 -5) and alcohol consumption ( B=1.036×10 -5, P=0.014, 95% CI: 0.211×10 -5-1.860×10 -5) and negatively correlated with hyperlipidemia ( B=-2.422×10 -5, P=0.015, 95% CI: -4.382×10 -5-0.462×10 -5). For each 1-mm increase in axial length, there was a decrease of 0.004 in vessel fractal dimension ( B=-0.004, P<0.001, 95% CI: -0.006--0.002), a decrease of 0.266 μm in the average vessel caliber ( B=-0.266, P=0.037, 95% CI: -0.516--0.016), and a decrease of -2.45×10 -5° in the average vessel tortuosity ( B=-2.45×10 -5, P<0.001, 95% CI: -0.313×10 -5--0.177×10 -5). For each 1.0 increase in BCVA, there was an increase of 3.992° in the vascular branch angle ( B=3.992, P=0.004, 95% CI: 1.283-6.702), an increase of 0.090 in vascular fractal dimension ( B=0.090, P<0.001, 95% CI: 0.078-0.102) and a decrease of 14.813 μm in the average vascular diameter ( B=-14.813, P<0.001, 95% CI: -16.474--13.153). Conclusions:A model for retinal vascular segmentation is successfully constructed.Retinal vessel parameters are associated with sex, age, systemic diseases, and ocular factors.
2.Structural and functional parameters of adult Macaca fascicularis retina
Keren LIAO ; Bin PENG ; Hongmei ZHENG ; Yifan LIU ; Yin SHEN
Chinese Journal of Experimental Ophthalmology 2024;42(1):12-18
Objective:To measure the retinal structural and functional parameters of adult Macaca fascicularis, and explore the similarity of the retinal structural and functional parameters between non-human primates and normal human retinas.Methods:Six eyes of 3 5-year-old adult Macaca fascicularis were examined by in vivo detection including color fundus photography, retinal optical coherence tomography (OCT) and electroretinogram (ERG) to determine the thickness of the inner/outer retina at the fovea and 1 000/2 000 μm away from the nasal, temporal, superior and inferior regions of the fovea, the thickness of the retinal nerve fiber layer (RNFL), the area of optic disc, the area of optic cup, the area ratio of cup to disc and the biological parameters of flash ERG.Differences in the above parameters between left and right eyes were analyzed.The similarity of parameters between Macaca fascicularis and human was compared with reference to published literature.The use and care of animals complied with the Regulation on the Management of Experimental Animals.The study protocol was approved by the Institutional Animal Care and Use Committee of Hubei Topgene Biotechnology (NO.IACUC-2019-012). Results:The foveal thickness, optic disc area, cup-disc area ratio, and average RNFL thickness in normal adult Macaca fascicularis were (252.31±4.79)μm, (1.89±0.05)mm 2, 0.14±0.01, and (103.53±0.58)μm, respectively.The b-wave amplitude of dark-adapted 0.01 ERG was (66.75±7.29)μV.The a- and b-wave amplitudes of dark-adapted 3.0 ERG response were (57.15±15.01) and (122.10±25.51)μV, respectively.The a- and b-wave amplitudes, the amplitude of oscillation potentials, and the latency of dark-adapted 10.0 ERG response were (72.98±20.14)μV, (131.67±13.78)μV, (49.98±10.08)μV, and (30.02±5.76)ms, respectively.The a- and b-wave amplitudes of light-adapted 3.0 ERG were (9.16±2.75) and (40.43±5.57)μV, respectively.The latency and the amplitude of the light-adapted 30 Hz flicker was (26.61±1.19)ms and (24.72±5.10)μV, respectively.There was no significant difference in the parameters between left and right eyes (all at P>0.05). The retinal thickness in central fovea, mean RNFL thickness, waveform and amplitude of ERG of Macaca fascicularis were similar to normal human. Conclusions:The structure and function of the retina of adult Macaca fascicularis are similar to those of normal humans.As a laboratory animal for preclinical drug research, in vivo studies of Macaca fascicularis can refer to normal human retinal parameters.
3.Metabolomics study of kidney tissue in a mouse model of oxygen-induced retinopathy
Lijun DONG ; Hui QI ; Yuhang YANG ; Xingxing MAO ; Guoming ZHANG ; Shaochong ZHANG ; Hetian LEI
Chinese Journal of Experimental Ophthalmology 2024;42(1):19-28
Objective:To explore the effects of hyperoxic environments on renal metabolites to understand the potential mechanisms that contribute to pathologic retinal vascular neovascularization and renal injury through metabolomic studies in a mouse model of oxygen-induced retinopathy (OIR) model.Methods:Sixteen C57/B6J mice pups born to day 7 (P7) were randomly and equally divided into an OIR model group and a normal control group using a randomized numerical table of mother mice.Mice were reared standardly from birth until day 7 (P7), then mice and their mother mice in the OIR group were placed in a hyperoxic (75±2)% chamber until day 12 (P12) and then reared normally.Mice in the normal control group were reared normally throughout.Mice in two groups were killed by carbon dioxide euthanasia on postnatal day 17 (P17). The mice retinal wholemount from the two groups were made and stained with isolectin B4 (IB4) to observe the morphology of retinal vessels, central non-perfusion area and pathological neovascularization.The kidney tissue of P17 mice was analyzed by liquid chromatograph mass spectrometer.After anticoagulant treatment, the whole blood of mice was centrifuged and precipitated, and the obtained plasma without cellular components was analyzed by targeted metabonomics.Mass spectral information was interpreted using metabolomics data processing software Progenesis QI v2.3.Overall differences in metabolic profiles were distinguished by unsupervised principal component analysis and orthogonal partial least squares analysis (OPLS-DA). The fold change and P values of metabolites were compared between the two groups.The variable importance of projection value>1 and P value<0.05 was used to screen out differential metabolites.Metabolic pathway enrichment analysis of differential metabolites was performed based on the KEGG database.The feeding and use of animals were strictly in accordance with the requirements of the Ethics Committee of Jinan University, and the research protocol was reviewed and approved by the Ethics Committee of Jinan University (No.20200401-54). Results:The IB4 staining of retinal wholemounts showed that the retinal blood vessels were evenly distributed in the P17 mice from control group.The peripheral retinal vessels were tortuous and disordered with a large non-perfusion area in central region in P17 mice from OIR group, and a large number of neovascularization clusters were formed at the junction of the nonperfusion area and the vascular area of the retina, showing strong fluorescent staining.The relative area of retinal nonperfusion area in OIR group was (25.16±3.50)%, which was significantly larger than (0.63±0.30)% in normal control group ( t=12.07, P<0.001). The OPLS-DA parameter R2X cum (0.578), interpretation rate R2Y cum (0.978) and prediction rate Q2 cum (0.857) values were all greater than 0.5, indicating that the OPLS-DA model had a good predictive ability.A total of 26 main differential metabolites were found, among which 17 were up-regulated and 9 were down-regulated, including glycerophospholipids (PC 20∶4(5Z, 8Z, 11Z, 14Z)/0∶0, PC 22∶6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z)/0∶0, PC 14∶1(9Z)/20∶2(11Z, 14Z), PE P-18∶0/20∶4(6E, 8Z, 11Z, 14Z)(5OH[S]), amino acid metabolites (arginine, ornithine, pipecolic acid, and hydroxylysine), purines (guanine, hypoxanthine, hydroxypurinol), and fatty acids (methyl 15-palmitate, 2, 6, 8, 12-tetramethyl-2, 4-tridecadien-1-ol), and so on.Differential metabolites were mainly enriched in ABC transporters (L-arginine, taurine, inositol, adenosine, N-acetyl-D-glucosamine, L-glutamine), aminoacyl-tRNA biosynthesis (L-isoleucine, L-proline, L-arginine, L-histidine, L-glutamine), arginine biosynthesis (L-arginine, L-ornithine, L-glutamine) metabolic pathways.The plasma targeted metabonomics showed that the differential amino acid metabolites were mainly enriched in metabolic pathways such as aminoacyl-tRNA biosynthesis, arginine biosynthesis and metabolism, and ABC transporters. Conclusions:ABC transporter, aminoacyl-tRNA biosynthesis, and arginine biosynthesis metabolic pathways in OIR mice may participate in the pathological changes of renal injury and neovascularization in retinopathy of prematurity.
4.Inhibitory effect of curcumin on malignant biological behavior and Wnt/β-catenin pathway of uveal melanoma cells
Xiaohong SHENG ; Liming WANG ; Xin ZHAO ; Xiangyang XIN
Chinese Journal of Experimental Ophthalmology 2024;42(1):29-37
Objective:To explore the inhibitory effect of curcumin on the malignant biological behavior of uveal melanoma (UM) and its possible mechanism.Methods:M23 cells were cultured in curcumin medium with different concentrations (0, 20, 40 and 80 μmol/L) for 48 hours, respectively.The morphological changes of cells were observed under an inverted microscope.The cell survival rate was detected by the cell counting kit-8 (CCK-8) method.The apoptosis, colony formation, migration and invasion of cells were detected by flow cytometry, plate clone formation experiment, cell scratch experiment and Transwell assay, respectively.The relative expressions of genes related to Wnt/β-catenin pathway, c-Myc, Cyclin D1, Survivin and matrix metallo proteinase 9 ( MMP-9) mRNA in cells were detected by real-time fluorescence quantitative PCR.The relative expressions of proteins related to Wnt/β-catenin pathway, c-Myc, Cyclin D1, Survivin, MMP-9 and β-catenin, glycogen synthase kinase 3β (GSK-3β), phosphorylated GSK-3β (p-GSK-3β) and axis inhibition protein 2 (Axin2) proteins were detected by Western blot.Another 20 female BALB/c mice were selected and injected with M23 cell suspension under the subcutaneous fat pad in the left posterior abdomen to establish the in vivo M23 transplanted tumor model.The mice successfully modeled were randomly divided into model group, low-dose curcumin group, medium-dose curcumin group and high-dose curcumin group according to the random number table method, which was intraperitoneally injected with 0, 10, 20 and 40 mg/kg curcumin physiological saline solution respectively.After a continuous injection for 30 days, the subcutaneous tumor was stripped and weighed.The animal experiment process followed the 3Rs principle of animal research and was approved by the Laboratory Animal Ethics Committee of Inner Mongolia Baotou Steel Hospital (No.2021MER-023). Results:The cell survival rate, the number of colony formation, the apoptosis rate, the cell invasion rate and the cell migration rate were (100.00±0.00)%, 128.67±9.18, (1.33±0.29)%, (89.76±4.57)% and 148.33±8.18 in 0 μmol/L curcumin group, (83.78±4.59)%, 100.33±8.73, (14.53±2.04)%, (65.43±3.70)% and 125.33±7.41 in 20 μmol/L curcumin group, (66.09±3.92)%, 58.67±6.55, (27.23±3.56)%, (34.83±2.19)% and 73.67±6.34 in 40 μmol/L curcumin group, and (47.16±3.63)%, 31.67±4.92, (44.73±4.36)%, (18.82±1.99)% and 45.67±5.31 in 80 μmol/L curcumin group.There were statistically significant differences in the survival rate, colony formation number, cell apoptosis rate, migration rate and invasion rate of M23 cells among the four groups ( F=125.321, 97.941, 72.516, 277.097, 139.006; all at P<0.001). With the increase of curcumin concentration, the cell survival rate, colony formation number, cell migration rate and cell invasion number decreased obviously, and the cell apoptosis rate increased obviously, and the pairwise comparisons showed significant differences (all at P<0.05). With the increase of curcumin concentration, the relative expression levels of c-Myc, Cyclin D1, Survivin, MMP-9 mRNA and proteins, β-catenin and p-GSK-3β proteins decreased significantly, while the relative expression level of Axin2 protein increased significantly, showing significant differences in pairwise comparisons (all at P<0.05). The tumor tissue weight of mice decreased with the increase of curcumin dosage, and the pairwise comparisons were statistically significant (all at P<0.05). Conclusions:Curcumin can inhibit the proliferation, migration, invasion and other malignant biological behaviors of UM M23 cells, inhibit tumor growth and promote cell apoptosis.Its mechanism may be related to blocking the activation of Wnt/β-catenin pathway.
5.Comparison of therapeutic effects between human amniotic membrane plugging and internal limiting membrane flap insertion for macular hole retinal detachment in high myopia
Chuqiao WANG ; Jibo ZHOU ; Tengteng YAO ; Zeqi WANG ; Huiqin GAO ; Zhaoyang WANG
Chinese Journal of Experimental Ophthalmology 2024;42(1):47-52
Objective:To compare the efficacy of pars plana vitrectomy (PPV) combined with human amniotic membrane (hAM) plugging technique or internal limiting membrane (ILM) flap insertion technique for high myopia macular hole retinal detachment (MHRD).Methods:A non-randomized controlled clinical study was performed.Sixteen eyes of 15 patients with high myopia MHRD treated in the Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine from July 2020 to August 2021 were included.All patients underwent PPV and were divided into hAM plug group (7 eyes of 7 patients) and the ILM insertion group (9 eyes of 8 patients) based on the different plugging materials.The best corrected visual acuity (BCVA) and intraocular pressure were measured before surgery and at 1 week, 1, 3, and 6 months postoperative, respectively.Slit-lamp microscopy combined with lenses, scanning laser ophthalmoscope and optical coherence tomography (OCT) were used to examine the fundus, the macular hole closure and retinal reposition.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine (No.SH9H-2021-T322-2). Written informed consent was obtained from each subject.Results:The retinal reattachment was achieved in 6 eyes in the hAM plug group and all 9 eyes in the ILM insertion group after initial surgery.The macular hole closure was observed in 5 eyes in the hAM plug group and 8 eyes in the ILM insertion group after initial surgery, and there was no statistical difference in the macular hole closure rate between the two groups ( P>0.05). There were significant differences in the overall comparison of BCVA between the two groups over time ( Ftime=4.420, P<0.05). Postoperative BCVA at different time points was better than preoperative BCVA in each group, but the differences were not significant (all at P>0.05). There was no significant difference in the overall comparison of BCVA between the two groups ( Fgroup=0.183, P>0.05). Two eyes in the hAM plug group and 4 eyes in the ILM insertion group developed transient ocular hypertension, which returned to normal after 1 week of treatment. Conclusions:Both PPV combined with hAM plugging technique and ILM insertion technique are safe and effective for the treatment of MHRD in high myopia.The hAM plugging technique can not only achieve anatomical reduction but also functional recovery of the retina even in complicated fundus conditions.
6.Comparative study of the efficacy of two intravitreal conbercept regimens in the treatment of polypoidal choroidal vasculopathy
Ran TANG ; Jiyang TANG ; Xinyao HAN ; Linqi ZHANG ; Xiaoxin LI ; Mingwei ZHAO ; Jinfeng QU
Chinese Journal of Experimental Ophthalmology 2024;42(1):53-59
Objective:To assess the efficacy and safety of the treat-and-extend (TAE) regimen and pro re nata (PRN) regimen of intravitreal conbercept in polypoidal choroidal vasculopathy (PCV) patients.Methods:A non-randomized controlled study was performed.Ninety-one patients (91 eyes) diagnosed with treatment-na?ve PCV from October 2016 to January 2019 at Department of Ophthalmology, Peking University People's Hospital were enrolled.All the patients received the intravitreal injection of 0.5 mg conbercept.After the initial treatment, the patients were divided into 3+ PRN group and 3+ TAE group according to their willingness.The follow-up time was one year.All the eyes underwent visual acuity test with ETDRS chart, optical coherence tomography (OCT) examination, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Best corrected visual acuity (BCVA), central retinal thickness (CRT), maximum retinal thickness (MRT), pigment epithelium detachment (PED) height, the number and area of polypoidal lesions, the area of retinal hemorrhage and the area of branching vascular network (BVN) were recorded.Treatment interval and injection frequencies during the one-year follow-up were compared between the two groups.This study adhered to the Declaration of Helsinki.The study protocol was approved by Peking University People's Hospital (No.2020PHB250-01). Written informed consent was obtained from each patient.Results:One-year after treatment, the BCVA improvement in the 3+ PRN group and 3+ TAE group was 5.0(-2.0, 15.0) and 6.0(-1.0, 14.0) letters, respectively, showing no significant difference ( Z=-0.352, P=0.725). No significant differences were found in CRT, MRT and PED height between the two groups ( Z=-0.145, -0.529, -0.985, all at P>0.05). There was no significant difference in polypoidal lesions number, polypoidal lesions area, the number of eyes with different degrees of polyp regression, BVN area and retinal hemorrhage area between the two groups ( Z=-0.502, -0.300, -0.047, -0.265, -1.243, all at P>0.05). After the one-year follow-up, the mean injection frequency of 3+ PRN group was (7.6±0.9) times, which was lower than (8.4±2.0) times of 3+ TAE group, showing a significant difference ( t=2.432, P=0.019). The mean follow-up frequency was (11.3±1.5) times of 3+ PRN group, which was significantly higher than (10.1±1.7) times of 3+ TAE group ( t=3.403, P=0.001). For the 3+ TAE group, 17.1%(6/35) of patients achieved an extension interval of 12 weeks after the first 3 doses, and 48.5%(17/35) of patients achieved an extension interval of 8 weeks or more, with a mean maximum extension interval of (9.5±2.0) weeks.During the follow-up, 10 patients in 3+ PRN group and 8 patients in 3+ TAE group received photodynamic therapy as a rescue treatment. Conclusions:The 3+ PRN and 3+ TAE regimens of intravitreal injection of conbercept combined with photodynamic therapy as a rescue treatment have similar efficacy in visual and anatomical outcomes for PCV patients.3+ TAE regimen has a higher treatment frequency and fewer follow-up visits.
7.Research progress on the inhibition of photoreceptor cell apoptosis by the pentose phosphate pathway and its molecular mechanism
Chinese Journal of Experimental Ophthalmology 2024;42(1):72-75
Photoreceptor cells are a special type of neuroepithelial cells, which play an important role in the generation and transmission of visual signals.They mainly meet the physiological needs by ingesting a large amount of glucose for glucose metabolism.Photoreceptor cell apoptosis is a common cause of blindness in patients with retinal diseases, which is accompanied by changes in oxidative stress and anabolism.Recent studies have found that pentose phosphate pathway, an important branch of glucose metabolism, plays an essential role in the development of the above-mentioned pathology.Its product, nicotinamide adenine dinucleotide phosphate (NADPH), as a crucial hydrogen donor in photoreceptor cells, participates in substance synthesis and metabolism, resists oxidative stress, and then inhibits apoptosis of photoreceptor cells.This review summarized the mechanism of pentose phosphate pathway in inhibiting photoreceptor cell apoptosis from the perspective of view of metabolic activity and molecular pathway to provide reference for clinical scientific research.
8.Aging and age-related macular degeneration
Chinese Journal of Experimental Ophthalmology 2024;42(1):76-79
With the aging of the population in modern society, the incidence of age-related diseases increases gradually, especially the age-related macular degeneration (AMD). Despite advances in treatment in recent years, AMD remains one of the leading causes of blindness and visual impairment in the elderly.At present, people tend to think that AMD is caused by the combination of aging and inflammation, which also contribute to the occurrence and development of many other age-related diseases.Although more studies have focused on the role of inflammation in AMD, aging, as an important correlate, is also deserves in-depth investigation.This article reviewed the close relationship between substance accumulation, abnormal phagocytosis, abnormal mitochondrial function and oxidative stress damage caused by aging and the occurrence and development of AMD, with a view to improving clinicians' knowledge of AMD.
9.Progress in programmed cell death of RPE cells in age-related macular degeneration
Qinghe JING ; Hongyu KONG ; Chen ZHAO
Chinese Journal of Experimental Ophthalmology 2024;42(1):80-85
Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly worldwide and is characterized by degeneration of the photoreceptor, retinal pigment epithelium, Bruch membrane and choriocapillaris complex.Impairment of RPE cell function is an early and critical event in the molecular pathways leading to clinically relevant AMD changes.Programmed cell death (PCD) plays an important role in response to stress and regulation of homeostasis and disease.In recent years, multiple studies have shown that apoptosis, pyroptosis, necroptosis and ferroptosis are likely involved in RPE cell PCD and correlate with the onset and development of AMD.There may be interaction or synergy between the various death pathways.This article reviewed the pathogenic mechanism of apoptosis, pyroptosis, necroptosis and ferroptosis in retinal pigment epithelial cell and their research progress in AMD, which might provide new approaches for the prevention and treatment of AMD.
10.Strategies to improve functional integration of transplanted photoreceptors
Jun WANG ; Yiqi CHEN ; Lijun SHEN
Chinese Journal of Experimental Ophthalmology 2024;42(1):86-91
The final outcome of the retinal degenerative diseases is the massive loss of photoreceptors, resulting in irreversible visual impairment which lacks effective treatment at present.As a potential therapeutic approach, photoreceptor transplantation can be used to restore retinal function to a certain extent by replacing the lost photoreceptors and rebuilding the retinal circuits.However, the discovery of material exchange unveiled a number of problems in previous studies, including low cellular integration, insufficient outer segment and synapse formation, highlighting the challenges of clinical translation.To explore the possibility of increasing the functional integration of photoreceptors, this article reviewed a variety of strategies, including selection of the transplanted cells with optimal developmental stage to enhance the interaction with the host retina, disruption of the outer limiting membrane and alleviation of retinal remodeling to improve the migration and integration of the transplanted photoreceptors, regulation of immunity can be used to reduce microglial activation to create a better host microenvironment for transplantation, use of retinal sheets or biological scaffolds to improve photoreceptor organization, rational development and use of biomaterials to optimize the physiological microenvironment of the transplanted cells, adequate evaluation of surgical parameters to reduce the effect of surgery on the transplanted cells and the host retina.

Result Analysis
Print
Save
E-mail