Targeted lipidomics uncovers oxylipin perturbations and potential circulation biomarkers in Bietti's crystalline dystrophy.

PURPOSE: Abnormalities in lipid metabolism have been proposed in Bietti's crystalline dystrophy (BCD). We aim to characterize the lipid profiles in a case-control study. METHODS: All participants were genetically confirmed by CYP4V2 gene sequencing and underwent chorioretinopathy evaluation by calculating the percentages of AF atrophy (PAFA). Fasting blood samples of BCD patients and controls were collected, and plasma was analyzed for routine lipid profiles. Targeted lipidomic evaluation includes long chain polyunsaturated fatty acids (LCPUFA) and associated eicosanoid metabolites. RESULTS: Routine lipids profiles showed elevated plasma levels of triglyceride (P = 0.043) and low-density lipoprotein cholesterol (P = 0.024) in BCD patients. Lipidomic analysis showed significantly decreased levels of ω-3 LCPUFA including docosahexaenoic acid (DHA, 22:6, P = 0.00068) and eicosapentaenoic acid (EPA, 20:5, P = 0.0016), as well as ω-6 LCPUFA arachidonic acid (ARA, 20:4, P < 0.0001) in BCD patients. Eicosanoid metabolites, either derived from ω-3 and/ or ω-6 LCPUFAs via cyclooxygenase (COX) or lipoxygenase (LOX) pathways, including 5-HEPE, 12-HEPE, 13-HDHA, 15-HETE, 12-HETE, 5-HETE, 6k-PGF1a, PGE2, PGJ2, and TXB2, exhibited significant differences (P < 0.0001) between BCD patients and controls. Genotypes of CYP4V2, specifically the biallelic null mutations, were observed to correlate with more remarkably reduced levels of oxylipins, involving major LOX pathway metabolites including 5-HETE, 5-HEPE, 12-HEPE and LTB4. CONCLUSIONS: BCD patients demonstrated significant decreases in plasma levels of ω-3 and ω-6 LCPUFA (DHA, EPA, and ARA), as well as their downstream metabolites via the COX and LOX pathways, suggesting that these might be implicated in BCD pathogenesis and could serve as biomarkers and therapeutic targets of the disease. KEY MESSAGES: What is known BCD is a vision-threatening hereditary disease the causative gene of which is CYP4V2. Abnormalities in lipid metabolism have been proposed and demonstrated previously in BCD studies. The detailed pathogenesis remains unclear and controversial. What is new We observed prominent lipidomic alterations in the circulation when compared with age, gender, and bodymass index (BMI)-matched healthy controls. BCD patients demonstrated significant decreases in plasma levels of ω-3 and ω-6 LCPUFA (DHA, EPA, and ARA). Remarkable changes were observed in the downstream metabolites of the LCPUFA via the COX and LOX pathways. Genotypes of CYP4V2, specifically the biallelic null mutations, were observed to correlate with more remarkably reduced levels of oxylipins, involving major LOX pathway metabolites.

CHARACTERIZATION OF MACULAR NEOVASCULARIZATION IN BIETTI CRYSTALLINE DYSTROPHY USING MULTIMODAL IMAGING MODALITIES.

PURPOSE: To characterize the clinical features of macular neovascularization (MNV) secondary to Bietti crystalline dystrophy. METHODS: The imaging data of 157 eyes in 79 patients with Bietti crystalline dystrophy were retrospectively reviewed. 12 individuals (19 eyes) were found to have MNVs. Multimodal retinal imaging was used to evaluate the features of MNVs and the primary chorioretinopathy. RESULTS: The MNV lesions were shown as typical type 2 MNVs with subretinal hyperreflective material (SHRM), and usually detected along the borders of the retinal pigment epithelium/choriocapillaris dropout. The active MNVs were noted in earlier stages of Bietti crystalline dystrophy, while the activity was observed to be reduced in advanced cases. On spectral domain optical coherence tomography, the outer retinal structures were demonstrated to be partially preserved above the SHRMs compared with the extensive atrophy contiguously. Fibrotic scaring of the MNVs was commonly observed and arteriolarization was usually shown within the scars. CONCLUSION: MNV was demonstrated to be a common complication secondary to Bietti crystalline dystrophy. The lesions were typical type 2 MNV of varied activities possibly associated with the degrees of the primary degeneration. Choriocapillaris hypoperfusion may participate in MNV development.

Observation of the characteristics of the natural course of Bietti crystalline dystrophy by fundus fluorescein angiography.

BACKGROUND: Bietti crystalline dystrophy (BCD) is an autosomal recessive genetic disorder that causes progressive vision loss. Here, 12 patients were followed up for 1-5 years with fundus fluorescein angiography (FFA) to observe BCD disease progression. METHODS: FFA images were collected for 12 patients with BCD who visited our clinic twice or more over a 5-year period. Peripheral venous blood was collected to identify the pathogenic gene related to the clinical phenotype. RESULTS: We observed two types in FFA images of patients with BCD. Type 1 showed retinal pigment epithelium (RPE) atrophy in the macular area, followed by choriocapillaris atrophy and the subsequent appearance of RPE atrophy appeared at the peripheral retina. Type 2 showed RPE atrophy at the posterior pole and peripheral retina, followed by choriocapillaris atrophy around the macula and along the superior and inferior vascular arcades and the nasal side of the optic disc. The posterior and peripheral lesions of both type 1 and type 2 BCD subsequently extended to the mid-periphery; finally, all the RPEs and choriocapillaris atrophied, exposing the choroid great vessels, but type 2 macular RPE atrophy could last longer. CONCLUSIONS: The characterization of two different types of BCD development provides a better understanding of the phenotype and the progression of the disease for a precise prognosis and prediction of pathogenesis.

[Inhibition effect on Microcystis aeruginosa PCC7806 as well as separation and identification of algicidal substances isolated from Salvinia natans (L.) All].

OBJECTIVE: To study the inhibition effect of Salvinia natans ( L. ) All. on harmful algae. METHODS: With Microcystis aeruginosa as the subjects, deionized water, ethanol, acetone, ethyl acetate as solvent, four kinds of crude extracts from Salvinia natans (L.) All. were prepared, and their alga-inhibiting actions were verified, respectively. The crude extracts of Salvinia natans (L.) All. with better inhibition effect were selected. The components of algal inhibiting material through macroporous resin purification were obtained, and determined by gas chromatography-mass spectrometry (GC-MS). RESULTS: The algicidal effect as follows: ethyl acetate extract > acetone crude extract > ethanol crude extract > water crude extract. Meanwhile, the inhibitory substances of Salvinia natans (L.) All. may be: diacetone alcohol, methyl isobutenyl ketone, 5-methyl-2-(1-methylethyl)-1-hexanol, pentadecanal, 14-heptadecenal, cumene, butyl acetate, ascorbyl dipalmitate, 1, 2-benzenedicarboxylic acid, mono (2- ethylhexyl) ester, dibutyl phthalate and phthalic acid, butyl undecane ester. CONCLUSION: The algal inhibiting effect research of Salvinia natans (L.) All., as well as its separation and identification of allelochemicals supplys theoretical basis and practical evidence not only for algae control, but also exploitation of algal inhibiting agent.

[Inhibition effect of aquaculture water of Salvinia natans (L.) All. on Microcystis aeruginosa PCC7806].

OBJECTIVE: To study the inhibiting effect of aquaculture water of Salvinia natans (L.) All. on Microcystis aeruginosa and the mechanism. METHODS: Microcystis aeruginosa of 7.5 x 10(5) cells/mL was treated by the culture water of Salvinia natans density of 5%, 10%, 20% and 40%, respectively. The inhibition ratios were calculated, conductivity of algal cells, content of nucleic acid and protein in algae solution, influence of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. RESULTS: The inhibition rate of 40% treatment group up to 100% on the fourth day. The inhibition rate of 5% treatment group up to 65% on the 7th day. The conductivity of algae cell gone up while the concentration of cultured water was increasing, as well as its content of nucleic acid, protein and MDA. However, the activity of SOD rose at first and then fall down while the concentration of cultured water of Salvinia natans was increasing. CONCLUSION: The aquaculture water of Salvinia natans has a powerful inhibitory effect on Microcystis aeruginosa by changing the structure of algal cells and intracellular enzyme activity, etc.

[Joint actions of Myriophyllum verticillatum L and its rhizospheric microorganisms on Microcystis aeruginosa and the mathematical model analysis].

OBJECTIVE: To study the inhibition effect on blue-green algae of higher aquatic plants with their rhizosphere microorganisms and its mathematical model. METHODS: The inhibitory effects of sterile and containing bacterium Myriophyllum verticillatum L root extracts on Microcystis aeruginosa were studied respectively, and the difference-differential equation of algal growth and partial functional differential equation were established according to the algal inhibiting effect. RESULTS: (1) The sterile and containing bacterium Myriophyllum verticillatum L root extracts showed at some degree inhibitory effects on M. aeruginosa, and containing bacteria root extract had more potent algal inhibiting effect, and very lower half maximal effective concentration (EC50). (2) The established inhibitory mathematical models can effectively predicted and calculated algal densities and EC50 at varying exposure time and different environment. CONCLUSION: The rhizospheric microorganisms can effectively enhanced the inhibiting effect of Myriophyllum verticillatum L on M. aeruginosa.

[Effect of salicylic acid on polysaccharide and microcystin contents in Microcystis aeruginosa PCC7806].

OBJECTIVE: To study the variation of polysaccharide (PS), which can be classified as capsule polysaccharide (EPS) and extracellular polysaccharide (EPS), and microcystin-RR (MC-RR) content of Microsystis aeruginosa under the stress of salicylic acid (SA). METHODS: 0, 0.25, 0.50, 0.75 and 1.00 mmol/L SA were added into the culture of M. aeruginosa at logarithmic phase and the contents of PS and MC-RR were quantified by phenol-sulfuric acid method and high performance liquid chromatography (HPLC) method in the 6th and 12th day. Meanwhile the effect of SA on PS and MC-RR contents were discussed at both the level of single cell and that of whole culture medium. RESULTS: CPS contents were increased with the increasing concentration of SA on the 6th day and decreases on the 12th day. The content of EPS and intracellular MC-RR first increases and then decreases with the increasing SA concentration in the whole stage. CONCLUSION: The contents of CPS and MC-RR increase for the stress of SA in early days, and then the contents of MC-RR both inside and outside the cell are decrease.

KFWC: A Knowledge-Driven Deep Learning Model for Fine-grained Classification of Wet-AMD.

BACKGROUND AND OBJECTIVES: Automated diagnosis using deep neural networks can help ophthalmologists detect the blinding eye disease wet Age-related Macular Degeneration (AMD). Wet-AMD has two similar subtypes, Neovascular AMD and Polypoidal Choroidal Vasculopathy (PCV). However, due to the difficulty in data collection and the similarity between images, most studies have only achieved the coarse-grained classification of wet-AMD rather than a fine-grained one of wet-AMD subtypes. Therefore, designing and building a deep learning model to diagnose neovascular AMD and PCV is a great challenge. METHODS: To solve this issue, in this paper, we propose a Knowledge-driven Fine-grained Wet-AMD Classification Model (KFWC) to enhance the model's accuracy in the fine-grained disease classification with insufficient data. We innovatively introduced a two-stage method. In the first stage, we present prior knowledge of 10 lesion signs through pre-training; in the second stage, the model implements the classification task with the help of human knowledge. With the pre-training of priori knowledge of 10 lesion signs from input images, KFWC locates the powerful image features in the fine-grained disease classification task and therefore achieves better classification. RESULTS: To demonstrate the effectiveness of KFWC, we conduct a series of experiments on a clinical dataset collected in cooperation with a Grade III Level A ophthalmology hospital in China. The AUC score of KFWC reaches 99.71%, with 6.69% over the best baseline and 4.14% over ophthalmologists. KFWC can also provide good interpretability and effectively alleviate the pressure of data collection and annotation in the field of fine-grained disease classification for wet-AMD. CONCLUSIONS: The model proposed in this paper effectively solves the difficulties of small data volume and high image similarity in the wet-AMD fine-grained classification task through a knowledge-driven approach. Besides, this method effectively relieves the pressure of data collection and annotation in the field of fine-grained classification. In the diagnosis of wet-AMD, KFWC is superior to previous work and human ophthalmologists.

Bietti's crystalline dystrophy: genotyping and deep qualitative and quantitative phenotyping in preparation for clinical trials.

PURPOSE: To qualitatively and quantitatively characterise the genotypes and phenotypes of Bietti's crystalline dystrophy (BCD) in a cohort of patients. DESIGN: Cross-sectional and observational study. METHODS: Clinically confirmed BCD patients were recruited for genotyping and phenotyping. Multiple retinal imaging modalities were employed. Atrophy in the fovea was adopted as major consideration for staging strategy, while percentage area of autofluorescence (AF) atrophy (PAFA) in the macula was determined for quantitation. RESULTS: In 74 clinically diagnosed BCD patients, c.802-8_810del17insGC was shown the predominant variant of the CYP4V2 gene (allele frequency 55.4%). Sixty-two cases (123 eyes) with full imaging data were classified according to a modified criterion into stages 1 (n=8, 6.50%), 2A (n=9, 7.32%), 2B (n=17, 13.82%), 3A (n=30, 24.39%) and 3B (n=59, 47.97%). The eyes of the stage 2B were particularly deemed 'high risk' due to atrophy near fovea, while in stage 3A, though with remarkable foveal atrophy, preserved retinal pigment epithelium/photoreceptor islands near the fovea were found in 14 eyes. A tendency of increase in PAFA with age was found (rs=0.31, p=0.014). Significant PAFA increase was shown through stages 1 to 3B, and best-corrected visual acuity (BCVA, Logarithm of the Minimum Angle of Resolution) was shown to moderately correlate with PAFA (rs=0.56, p<0.001). CONCLUSION: The PAFA might be an efficient biomarker for BCD severities correlating with BCVA. The highly heterogeneous chorioretinopathy and BCVA of BCD cases appear to be associated with disease stages, progression types and patients' ages. Foveal involvement should be of a major concern for consideration of potential therapeutic intervention.

The Relationship between VEGF-C, TAM, and Lymph Node Metastasis in Oral Cancer.

Objective: To investigate the relationship between vascular endothelial growth factor-C (VEGF-C) and tumor-associated macrophages in oral cancer (TAMs) with lymph node metastasis. Method: From January 2018 to January 2022, 155 cases of oral cancer tissues and 165 cases of normal mucosal tissues were collected from oral surgical resection tissues or biopsy specimens in Hebei Eye Hospital. Oral cancer tissues were observed. The control group had normal mucosal tissues. The clinical and immune parameters were observed and the treatment of oral cancer is also briefly discussed. Results: The number of TAMs and the expression of VEGF-C in oral cancer tissues were significantly higher than those in normal tissues (P < 0.05). The lymphatic vessel density, the number of TAMs, and the expression of VEGF-C in the metastatic group were higher than in nonmetastatic group, and the lymphatic vessel density, the number of TAMs, and the expression of VEGF-C in the paracancerous tissues were higher than central tumor tissue in the metastatic group (P < 0.05). Univariate analysis showed that the number of TAMs was related to the histological stage and the pathological type of oral cancer (P > 0.05). The expression of VEGF-C was associated with the histological stage of oral cancer (P < 0.05). Compared with the immune function after different treatments, the contents of CD4+ in both groups was higher than before, and the combined treatment group was increased more than single treatment group (P < 0.05). The contents of CD3+ and CD8+ in the two groups were lower than before, and the combined treatment group was decreased higher than combined treatment group (P < 0.05). Conclusions: The number of TAMs and the expression of VEGF-C in oral cancer tissues are higher than normal tissues. The number of TAMs and the expression of VEGF-C are higher in patients with lymph node metastasis. TAMs and VEGF-C may play an important role in lymph node metastasis of oral cancer. Integrated traditional Chinese and Western medicine can improve the immune function of patients with oral cancer and may improve the therapeutic efficacy.

Multimodal imaging study of lipemia retinalis with diabetic retinopathy: A case report.

BACKGROUND: Lipemia retinalis (LR) is a rare disease related to hypertriglyceridemia. However, the symptoms of hypertriglyceridemia are insidious and difficult to detect without blood tests. The fundus is the only site where blood vessels can be observed directly. Understanding the specific performance of LR in multimodal imaging fundus examinations can help diagnose more patients with abnormal hyperlipidemia. CASE SUMMARY: A 29-year-old woman with type 2 diabetes presented to our clinic complaining of a six-day loss of visual acuity in the left eye. The fundus color images showed typical LR: Arteries and veins were the same pink-white color. Infrared images showed hyperinfrared reflections of the arteries and veins. Optical coherence tomography (OCT) showed numerous high point-like reflections in the retinal section, corresponding to different calibers of blood vessel sections. Medium reflections were seen in the big vessels of the choroid. Fundus fluorescein angiography (FFA) and optical coherence tomography angiography (OCTA) showed no significant changes. Laboratory examination found a total cholesterol level of 13.98 mmol/L, triglyceride 20.55 mmol/L, which confirmed the diagnosis of LR. After treatment to lower blood lipids and control blood glucose, the fundus imaging showed that the blood lipids in the patient had returned to normal. CONCLUSION: LR shows specific changes in fundus color photography, infrared photography, and OCT. FFA and OCTA were not sensitive to LR changes.

Multimodal Imaging Observation in Different Progressive Types of Bietti Crystalline Dystrophy.

Objective: The aim of the study is to observe the difference in progression between type 1 and type 2 Bietti crystalline dystrophy (BCD) using multimodal imaging. Methods: A retrospective clinical study was performed with six BCD patients who underwent multimodal imaging twice in Hebei Provincial Eye Hospital from October 2015 to December 2020. Multimodal imaging includes color fundus photography, fundus autofluorescence (AF), infrared autofluorescence (IRAF), fundus fluorescein angiography (FFA), and spectral domain optical coherence tomography (SD-OCT). The fundus lesion progression difference was observed in 3 patients with type 1 BCD and 3 patients with type 2 BCD. Results: In type 1 BCD, the range of hypoautofluorescence (hypo-AF), hypoinfrared autofluorescence (hypo-IRAF), and hypofluorescence in the posterior pole was enlarged, and FFA showed that the lesions in the posterior pole and periphery extended to the middle periphery. SD-OCT revealed retinal and choroidal thinning, progressive loss of the outer nuclear layer and ellipsoid zone, and reduction of the choroid macrovascular diameter. In type 2 BCD, the range of hypo-AF was enlarged, but there was no significant change in the macula area. The uniform hypo-IRAF in the posterior pole showed no significant change. FFA showed no significant change with the progression of the disease in the macula area and the hypofluorescence around it expanded. SD-OCT revealed no obvious change in the macula area. Conclusions: The retinal choroid atrophy in the macula area of type 1 BCD continued to worsen, and the choroid great vessels became narrower. The macular lesions of type 2 BCD can remain unchanged for a long time.

MBNM: Multi-branch network based on memory features for long-tailed medical image recognition.

BACKGROUND AND OBJECTIVES: Deep learning algorithms show revolutionary potential in computer-aided diagnosis. These computer-aided diagnosis techniques often rely on large-scale, balanced standard datasets. However, there are many rare diseases in real clinical scenarios, which makes the medical datasets present a highly imbalanced long-tailed distribution, leading to the poor generalization ability of deep learning models. Currently, most algorithms to solve this problem involve more complex modules and loss functions. But for complicated tasks in the medical domain, usually suffer from issues such as increased inference time and unstable performance. Therefore, it is a great challenge to develop a computer-aided diagnosis algorithm for long-tailed medical data. METHODS: We proposed the Multi-Branch Network based on Memory Features (MBNM) for Long-Tailed Medical Image Recognition. MBNM includes three branches, where each branch focuses on a different learning task: 1) the regular learning branch learns the generalizable feature representations; 2) the tail learning branch gains extra intra-class diversity for the tail classes through the feature memory module and the improved reverse sampler to improve the classification performance of the tail classes; 3) the fusion balance branch integrates various decision-making advantages and introduces an adaptive loss function to re-balance the classification performance of easy and difficult samples. RESULTS: We conducted experiments on the multi-disease Ophthalmic OCT datasets with imbalance factors of 98.48 and skin image datasets Skin-7 with imbalance factors of 58.3. The Accuracy, MCR, F1-Score, Precision, and AUC of our model were significantly improved over the strong baselines in the auxiliary diagnosis scenario where the clinical medical data is extremely imbalanced. Furthermore, we demonstrated that MBNM outperforms the state-of-the-art models on the publicly available natural image datasets (CIFAR-10 and CIFAR-100). CONCLUSIONS: The proposed algorithm can solve the problem of imbalanced data distribution with little added cost. In addition, the memory module does not act in the inference phase, thereby saving inference time. And it shows outstanding performance on medical images and natural images with a variety of imbalance factors.

Comparison of foveal avascular zone and retinal vascular density in healthy Chinese and Caucasian adults.

PURPOSE: The aim of this study was to measure and compare the retinal vascular parameters and foveal avascular zone (FAZ) in Chinese and Caucasian populations by using optical coherence tomography angiography (OCT-A). METHODS: Fifty-one eyes of Han Chinese and 43 eyes of Caucasians were retrospectively included in our study. The measurements were acquired using Zeiss Cirrus 5000, with the same software version 10 in Poland and China. RESULTS: The size of the FAZ was 0.33 ± 0.012 and 0.28 ± 0.014 mm2 (p = 0.0289) and the diameter was 2.43 ± 0.06 and 2.18 ± 0.07 mm (p = 0.0057) for Chinese and Caucasian populations, respectively. However, no differences were observed in circularities between the populations. The full Early Treatment of Diabetic Retinopathy Study (ETDRS) vessel length density was significantly different for Chinese (17.05 ± 0.24 mm/mm2 ) and Caucasian (16.08 ± 0.43 mm/mm2 ) populations. In addition, the outer ETDRS vessel length density was significantly different for Chinese (16.43 ± 0.42 mm/mm2 ) and Caucasian (17.47 ± 0.24 mm/mm2 ) populations, but the central 7.33 ± 1.68 versus 9.32 ± 1.54 mm/mm2 for the Caucasian and Chinese and inner 16.14 ± 0.52 for Caucasian and 16.93 ± 0.27 mm/mm2 for Chinese subjects density was not. A significant yet weak positive correlation between FAZ and vessel density was observed (r = 0.216). Furthermore, no significant intersexual differences were observed in study parameters. CONCLUSION: The Chinese population had larger FAZ with higher vessel length density in the superficial layers of the retina than the Caucasian population.

Comparison of effectiveness between complete internal limiting membrane peeling and internal limiting membrane peeling with preservation of the central fovea in combination with 25G vitrectomy for the treatment of high myopic foveoschisis.

Vitrectomy combined with internal limiting membrane peeling (ILMP) treats high myopic foveoschisis with good results, but there is a risk of iatrogenic macular holes, which may be reduced by preserving the internal limiting membrane of the central fovea. This study compared complete ILMP with partial ILMP, both combined with 25G vitrectomy, for the treatment of high myopic foveoschisis.Thirty-three cases (33 eyes) of high myopic foveoschisis were retrospectively analyzed. They underwent 25G vitrectomy combined with C3F8 gas filling; Group A (20 patients, 20 eyes) underwent complete ILMP, while Group B (13 patients, 13 eyes) underwent partial ILMP to preserve the internal limiting membrane of the central fovea. Patients were followed up for 6 months and underwent best corrected visual acuity (BCVA), intraocular pressure, diopter, slit lamp microscopy, indirect ophthalmoscope, A-mode and/or B-mode ultrasound, and optical coherence tomography. Surgical complications were recorded.Up to the last follow-up, the BCVA improved and central fovea thickness (CFT) was lower compared with before surgery in both groups (All P < .05). There were no significant differences in BCVA and CFT at each time point between the groups (P > .05). Most of the postoperative retinas of the 2 groups were completely reattached, with disappearance of the macular retinoschisis cavity. Two patients in the Group A and none in the Group B developed a macular hole during follow-up (P = .508).The results did not support the superiority of partial ILMP over complete ILMP in reduced incidence of macular hole. Both methods had a similar curative effect.

Inhibition of Obtusifolin on retinal pigment epithelial cell growth under hypoxia.

AIM: To explore the effect of Obtusifolin on retinal pigment epithelial cell growth under hypoxia. METHODS: In vitro chemical hypoxia model of ARPE-19 cells was established using cobalt chloride (CoCl2). Cell viability was tested by cell counting kit-8 (CCK-8) assay. Western blot and real-time quantitative polymerase chain reaction were applied to detect proteins and mRNAs respectively. Flow cytometry was used to examine the cell cycle. Secretion of vascular endothelial growth factor (VEGF) was tested by using enzyme linked immunosorbent assay (ELISA). RESULTS: Under the chemical hypoxia model established by CoCl2, hypoxia inducible factor-1α (HIF-1α) mRNA and protein levels was up-regulated. Cell viability was increased and the proportion of S phase was higher. Obtusifolin could reduce cell viability under hypoxic conditions and arrest cells in G1 phase. Obtusifolin reduced the expression of Cyclin D1 and proliferating cell nuclear antigen (PCNA) in the hypoxic environment and increased the expression of p53 and p21. The levels of VEGF, VEGFR2 and eNOS proteins and mRNA were significantly increased under hypoxia while Obtusifolin inhibited the increasing. CONCLUSION: Obtusifolin can inhibit cell growth under hypoxic conditions and down-regulate HIF-1/VEGF/eNOS secretions in ARPE-19 cells.