Effect of aflibercept combined with triamcinolone acetonide on aqueous humor growth factor and inflammatory mediators in diabetic macular edema

AIM:To investigate the efficacy of aflibercept combined with sub-tenon injection of triamcinolone acetonide(TA)in treating diabetic macular edema(DME)and to examine changes in growth factors and inflammatory mediator levels in aqueous humor after injection.METHODS:Totally 67 DME patients(67 eyes)and 30 cataract patients(32 eyes)were enrolled as the DME group and the control group,respectively.The DME group was divided into the aflibercept group(34 cases)and the aflibercept combined with TA group(combined group,33 cases).The aqueous humor of both groups was collected during the study period.The aqueous levels of vascular endothelial growth factor(VEGF),monocyte chemoattractant protein-1(MCP-1),interleukin-6(IL-6),interleukin-8(IL-8),and interleukin-1β(IL-1β)were detected using a microsphere suspension array technology(Luminex 200TM).Aqueous cytokines,best-corrected visual acuity(BCVA),central macular thickness(CMT),and complications before and after treatment were compared between the aflibercept group and combined group.RESULTS:The concentrations of VEGF,MCP-1,IL-6,and IL-8 in the aqueous humor were significantly higher in the DME group than those of the control group(all P<0.01).After 1mo of surgery,the concentrations of VEGF,MCP-1,IL-6,and IL-8 in the aqueous humor were significantly lower in the combined group than those of the aflibercept group(all P<0.01).The BCVA and CMT values of the two groups were statistically different after 1 and 2mo of treatment(P<0.01).However,the difference was not statistically significant after 3mo of treatment(P>0.05).CONCLUSION:The cytokines VEGF,MCP-1,IL-6,and IL-8 in the aqueous humor of DME patients are significantly increased.Aflibercept and aflibercept combined with TA have good efficacy in DME patients,can effectively reduce CMT,improve the patient’s vision,and have high safety.Aflibercept combined with TA can quickly downregulate the aqueous humor cytokines and help to relieve macular edema rapidly.However,the long-term efficacy is comparable to that of aflibercept alone.

Research progress on the correlation between aqueous humor components and pathogenesis and postoperative complications in patients with different types of cataracts

Aqueous humor provides the necessary nutrition for the lens and transports the metabolites in the eye.It was a liquid that can directly reflect the microenvironment in the eye'and it can be easily obtained during the operation.This review intended to analyze the components of aqueous humor in patients with different types of cataracts'so as to reflect the pathogenesis and development of the disease'evaluate the incidence of postoperative complications and provide reference value for the surgical design of sequential cataract surgery.The aqueous humor components of different types of cataracts showed different degrees of inflammation'oxidative stress and extracellular matrix remodeling.The biomarker of early neuropathy in diabetic cataract was neural cell adhesion molecule-1(NCAM1).Transforming growth factor-β(TGF-β)was the evaluation factor of disease development in patients with pseudoexfoliation syndrome.The relationships between postoperative complications of different types of cataracts and aqueous humor components were as follows:Macular edema after diabetic cataract surgery was associated with tumor necrosis factor-alpha;capsular contraction after high myopic cataract surgery was related to monocyte chemoattractant protein-1(MCP-1)and TGF-β2;Klotho and glutathione S-transferase P 1(GSTP1)were associated with high intraocular pressure after primary open-angle glaucoma complicated by cataract surgery;capsular contraction after retinitis pigmentosa complicated by cataract surgery was associated with matrix metalloproteinases;pro-inflammatory cytokines and fibroblast growth factor 4 in the aqueous humor of congenital cataracts were associated with posterior capsular opacification after surgery.Granulocyte colony stimulating factor 3 and MCP-1 were the main cytokines mediating the pain of the second eye in the binocular sequential cataract surgery short interval(1 wk)'while MCP-1 mediated pain in the long interval(6 wk).The second eye after binocular sequential cataract surgery had a higher level of proinflammatory factors.The components of aqueous humor in patients with different types of cataracts were related to the pathogenesis and postoperative complications of the disease.Monitoring the components of the aqueous humor could help better understand the intraocular microenvironment of different types of cataracts and provide a reference for predicting the development of the disease and implementing relevant targeted therapy.

Differential analysis of aqueous humor cytokine levels in patients with macular edema secondary to diabetic retinopathy or retinal vein occlusion

AIM:To evaluate the difference and the correlation between the concentrations of cytokines in the aqueous humor of eyes with macular edema secondary to diabetic retinopathy(DR)or retinal vein occlusion(RVO).METHODS:This is a retrospective case control study.The aqueous humor samples were collected during intravitreal injection of anti-vascular endothelial growth factor(VEGF)for patients diagnosed with macular edema secondary to DR(DME)or RVO(RVO-ME)at Xijing Hospital from August 2021 to July 2022.Meanwhile,aqueous humor samples during vitrectomy from patients with idiopathic macular hole(IMH)were also collected and served as controls.The aqueous humor concentrations of VEGF,platelet-derived factor(PDGF),interleukin(IL)-6,IL-8,IL-18,tumor necrosis factor-α(TNF-α)and monocyte chemoattractant protein 1(MCP-1)were measured with Human Premixed Multi-Analyte Kit(Luminex).The difference of the aqueous cytokines and the correlation between the two diseases were analyzed.RESULTS:A total of 40 eyes of 38 patients were enrolled in the study,including 13 eyes of 11 DME patients(DME group),16 eyes of 16 RVO-ME patients(RVO-ME group)and 11 eyes of 11 IMH patients(control group).The VEGF,PDGF,IL-6,IL-8,and MCP-1 levels of the aqueous humor were higher in both DME and RVO-ME groups compared with the control group(all P<0.05),the levels of TNF-αwas higher in the DME group than in the control group(P<0.05).The VEGF,IL-6,MCP-1,and TNF-αlevels in the aqueous humor were significantly higher in the DR group than those in the RVO group(all P<0.05).Correlation analyses revealed that there were complex positive correlations between IL-6,IL-8,IL-18,MCP-1,and TNF-αlevels in the aqueous humor of eyes with two diseases.CONCLUSION:Although ischemic and inflammatory factors are similarly involved in the pathogenesis of DME and RVO-ME,the roles of these factors are more significant or more likely to be activated in DR patients,suggesting different treatment strategies should be considered for the two diseases.

Increased melatonin levels in aqueous humor of patients with proliferative retinopathy in type 2 diabetes mellitus

AIM： To report the association between melatonin levels in aqueous humor and serum, and diabetic retinopathy（DR） grade in type 2 diabetic patients.·METHODS： Aqueous humor and plasma samples from26 patients with DR（in nonproliferative and proliferative stages） and 14 control subjects were collected during cataract surgery after 6 p.m. Melatonin concentrations were determined using an enzyme-linked immunosorbent assay（ELISA）.·RESULTS： Melatonin levels were significantly higher in the aqueous humor of patients with proliferative diabetic retinopathy（PDR） [18.57 ±2.67 pg/m L（range 15.20-23.06）vs 13.63±2.71 pg/m L（range 10.20-20.20）, P =0.0001], but not in those with nonproliferative retinopathy（NPDR）[13.79±2.56 pg/m L（range 9.80-20.10） vs 13.63±2.71 pg/m L（range 10.20-20.20）, P =0.961] compared to controls. There was decrement in the plasma melatonin level of patients with PDR, but no significant differences between the plasma melatonin levels of the study groups [ 5. 37 ±1.74 pg/m L（range 2.85-8.65） vs 6.11±1.90 pg/m L（range3.13-9.41）, P =0.293], or between control and DR groups[NPDR 6.11 ±1.90 pg/m L（range 3.13-9.41） vs control6.15±1.91 pg/m L（range 2.18-9.86）; PDR（5.37±1.74 pg/m L（range 2.85-8.65） vs control 6.15 ±1.91 pg/m L（range2.18-9.86）, P =0.808, P =0.264].·CONCLUSION： Elevated melatonin levels in aqueous humor in PDR may indicate the level to be associated with DR severity.

iTRAQ-based proteomics analysis of aqueous humor in patients with dry age-related macular degeneration

AIM: To preliminarily test proteomics in aqueous humor in patients with dry age-related macular degeneration(AMD) by using the proteomic technology.METHODS: Aqueous humor samples were collected from patients with or without dry AMD, who underwent cataract surgery. The aqueous samples were analyzed with isobaric tags for relative and absolute quantification(i TRAQ) combined with liquid chromatography tandem mass spectrometry(LC-MS/MS) technology. The differential expressed proteins were analyzed with gene ontology(GO) enrichment, Kyoto Encyclopedia of Genes and Genomes(KEGG) and protein-protein interaction(PPI) network analysis. The data were partly validated by ELISA and Western blot. False discovery rate(FDR) was used for statistical analysis. RESULTS: A total of 244 proteins were detected, in which 38 proteins were up-regulated and 51 were down-regulated significantly in patients with dry AMD compared with that in control groups(FDR value <1.0%). Several proteins, e.g., protein S100-A8(S10 A8), dystroglycan(DAG1), Ig alpha-1 chain C region(IGHA1), carbonic anhydrase 3(CAH3) and alpha-1-acid glycoprotein(A1 AG1) were increased more than 5 times of that in control group. The bioinformatics analysis showed that dry AMD is closely associated with inflammation or immune reaction, oxidative stress, blood coagulation and remodeling of extracellular matrix.CONCLUSION: i TRAQ-based proteomic analysis of aqueous humor demonstrate the differential expressions of proteins between dry AMD and control groups, providing the clues to understand the mechanisms and possible treatments of dry AMD.

Changes of total antioxidant capacity and total oxidant status of aqueous humor in diabetes patients and correlations with diabetic retinopathy

AIM:To measure changes of total oxidant status(TOS)and total antioxidant capacity(TAC) of aqueous humor(AH) in diabetic retinopathy(DR) patients,and to determine if there were any differences in TOS and TAC of AH in diabetic patients without retinopathy compared with non-diabetic patients.·METHODS:One hundred and three eyes of 103patients who were enrolled for cataract surgery were included in this study.Patients were grouped according to presence of diabetes and stage of DR.Prior to cataract surgery,0.1mL to 0.2mL of AH was aspirated and analyzed for TAC and TOS level using a colorimetric method.·RESULTS:TOS levels were highest among proliferative diabetic retinopathy(PDR) patients and lowest in patients with only cataracts.Results were statistically significant between all groups(P 【0.05).Whereas result between diabetic without retinopathy patients and non-proliferative diabetic retinopathy(NPDR) patients was not statistically significant(P =0.757).TAC levels were highest in patients with only cataract and lowest among PDR patients and results were statistically significant between all groups(P 【0.05).·CONCLUSION:Aqueous humor TAC levels are low in diabetic patients and reduced further in DR patients,TOS levels are increased in diabetic patients and this is exacerbated in DR patients.

Relationship between raised intraocular pressure and ischemia-modified albumin in serum and humor aqueous: a pilot study in rabbits

AIM:To evaluate the relationship between increased intraocular pressure(IOP),is chemia-modified albumin levels in serum(IMA-s)and in humor aqueous(IMA-HA)in rabbits.METHODS:Twenty-five albino New Zealand rabbits weighing between 2.0 and 2.8 kg were used in this pilot study.With permission from Canakkale Onsekiz Mart University Animal Ethics Committee,the IOP of both eyes of each rabbit were recorded with a Tonopen(Tono-Pen XL,Reichart Inc.,Depew,NY,USA)after the application of topical proparacaine 0.5%HCl anesthesia.Blood(4 mL)was collected from the marginal ear vein and an intracameral injection of 2.3 mg/mL sodium hyaluronate and subconjunctival dexamethasone was given in the right eye.Anterior chamber aqueous fluid was obtained using a limbal approach with a 27 gauge needle from both eyes.The left eyes were used as controls.IOP was measured on the 1st,3rdand 10thday after the initial injection,with Tonopen,IMA-s levels and IMA-HA examined simultaneously.RESULTS:Beforetheinjections,IOPwas11.4±3.0mmHg in the right eye and 11.3±3.1 mm Hg in the left eye(P】0.05).There was a statistically significant difference between IMA-s levels before the IOP increase(IMA-s0)and IMA-s levels on the 1stand 3rddays after the increase in IOP(P=0.012 and P=0.01,respectively).No difference was observed between IMA-s0and serum IMA levels on the 10thday(IMA-s10)after IOP increase(P=0.989).IMA-HA in the right eye in the first day after the injection was positively correlated with IOP(r=0.748;P=0.02).No othercorrelation is found between any other parameter with IMA-HAlevels at any test time.A statistically significant positive correlation was observed between IMA-s values and IOP on the 1stand 3rddays(r=0.398,P=0.04 and r=0.382,P=0.04,respectively).There was no correlation between IMA-s levels and increased IOP on the 10thday after IOP increase(r=0.026,P=0.902).CONCLUSION:IMA may be an important indicator of acute damage caused by diseases involving ischemic damage to the eye,especially in case of increased intraocular pressure.

Age-related pro-inflammatory and pro-angiogenic changes in human aqueous humor

AIM： To reveal age-related aqueous cytokine changes in human aqueous humor.METHODS： Aqueous humor was collected from 12 young children（3-6.5 years old） and 71 healthy adults（22-106 years old） with cataract but without other systemic or ocular disorders. Levels of 22 cytokines, chemokines and vascular endothelial growth factor（VEGF） were measured and analyzed.RESULTS： The following proteins showed significant increase from childhood to adult： interferon-gamma（IFN-γ）, interleukin（IL）-13, IL-6, IL-12（p70）, IL-10, CCL2, CCL3, CCL4, CXCL8, CXCL9, CXCL10, IFN-α2 and VEGF（all P〈0.05）. IFN-γ, IL-13, IL-12（p70）, IL-10, CCL3, CXCL9 and VEGF also showed moderate strength age-related increase in the adult group（r〉0.5）. The strength of correlation between aging and CCL4 were fair（r=0.398）. The concentrations of IL-2, IL-4, IL-5, IL-1β and TNF-α were low in both groups.CONCLUSION： From childhood to adult, the immunological milieu of the anterior chamber become more pro-inflammatory and pro-angiogenic. Such changes may represent the parainflammation state of the human eye.

Concentration change of TGF-β1 in aqueous humor of rabbits

Objective:To observe the influence of the the transforming growth factorβ1(TGF-β1)eve drops on rabbit aqueous humor TGF-β1 concentration,and to analyze the best drug concentration.Methods:A total of 30 New Zealand white rabbits were randomly divided into5 groups with 6 in each.Habits in control group had PBS eye drops,group A,B.C,D adopted TGF-β1 eye drops at 0.5,1.0.2.0.4.0 mg/L,respectively.4 times a day.Aqueous humor of right eye was extracted 1 week after administration lo delect concentration changes of TGF-β1 by ELISA;rabbits in fpur hroups adopted 2.0 mg/L eye drops to left eyes 4 times a day,0.2 mL aqueous humor was extracted left eye at the scheduled time point 0,30 min,2 h,4 h,24 h for testing,the slit lamp was used to observe the cornea,chamber and lens.Results:No obvious pathological changes in conjunctiva,cornea,rabbit conjunctival,anterior chamber,and the lens was found.Concentration of TGF-β1 in rabbit aqueous humor in C.D group was significantly higher than the control group(P<0.05).Conclusions:TGF-β1 eye drops at 2.0 mg/L.4.0 mg/L can significantly increase concentration of TGF-β1 in rabbit aqueous humor,withe good ocular surfac permeability.

LMWH inhibits anterior chamber inflammation after extra capsular lens extraction through down regulation of bFGF content in aqueous humor

AIM: To observe the changes of basic fibroblast growth factor (bFGF) content in anterior chamber before and after extra capsular lens extraction for investigating the mechanism of low molecular weight heparin (LMWH) inhibiting anterior chamber inflammation. METHODS: Eighty-four rabbits were randomly divided into control and experimental group, 42 rabbits in each group. Extra capsular lens extraction was done on unilateral eye in each rabbit. LMWH was perfused into anterior chamber by the concentration of 50U/mL at the end of operation in experimental group. The degrees of corneal edema, aqueous flare and fibrin were evaluated with slit lamp microscope in postoperative day 1, 3, 6, 15, 30, 45 and 60, respectively. Six eyes of each group were at each time point. Contents of bFGF in aqueous humor were determined by ELISA after animals were killed. Another six eyes were used for determining the base line level of bFGF in aqueous humor. RESULTS: The degrees of corneal edema, aqueous flare and fibrin in experimental group were significantly lighter than those in control group (p<0.01) on postoperative day 1, 3 and 6, respectively. No difference was showed between the two groups at other point time. Contents of bFGF in aqueous humor increased at the same time. bFGF content was reached peal on postoperative day 1 in experimental group, while on postoperative day 6 in control group. Contents of bFGF in the two groups declined slowly after reaching peak. The bFGF content in control group were significantly higher than that in experimental group 1-30 days after surgery (p<0.05). No significant differences were shown between the two groups on postoperative day 45 and 60, respectively. CONCLUSION: Perfusion with LMWH by the concentration of 50U/mL can significantly reduce anterior chamber inflammation after extra capsular lens extraction in rabbits, which may be related to down regulation of bFGF content in aqueous humor.

Aqueous proinflammatory cytokines in acute primary angle-closure eyes

AIM：To evaluate changes of proinflammatory cytokines in aqueous humor of patients with acute primary angleclosure（APAC） and age-related cataracts. METHODS：Twenty eyes of 20 APAC patients and 15 eyes of 15 age-related cataract patients were included in this cross-sectional study. Aqueous humor samples were collected prospectively. The levels of 20 proinflammatory cytokines were evaluated in the aqueous humor of the APAC and cataract patients using the multiplex bead immunoassay technique. Clinical data were collected for correlation analysis.RESULTS：Seven of the 20 proinflammatory cytokines included in the magnetic bead panel were detectable in both APAC eyes and cataract eyes：interleukin（IL）-10, IL-12, IL-15, IL-21, IL-6, chemokine（C-C motif） ligand 20, and tumor necrosis factor alpha（TNF-α）. IL-27 was only detectable in APAC eyes. Compared with the cataract eyes, the APAC eyes had significantly elevated concentrations of IL-12（P=0.036）, IL-15（P=0.001）, IL-6（P=0.012）, and IL-27（only detectable in APAC eyes）. Age was positively correlated with IL-12（P=0.022） and IL-6（P=0.037）, and time elapsed between APAC onset and aqueous humor samples collection was positively correlated with IL-15（P=0.037）, IL-27（P=0.040）, and TNF-α（P=0.042）.CONCLUSION：Several proinflammatory cytokines including IL-12,IL-15, IL-6 and IL-27, were elevated in the APAC eyes and may be implicated in its pathologic mechanism.

Proteome alterations in aqueous humour of primary open angle glaucoma patients

AIM: To unravel the primary open angle glaucoma(POAG) related proteomic changes in aqueous humour(AH).METHODS: Totally 35 patients listed for cataract surgery(controls: n=12, age: 67.4±13.6 y) or trabeculectomy for POAG(n=23, age: 72.5±8.3 y) were included. AH samples of those patients were obtained during cataract surgery or trabeculectomy. AH samples were subsequently pooled into the experimental groups under equal contribution in terms of protein amount of each individual patient. Protein samples were analyzed by a linear trap quadrupol Orbitrap Mass Spectrometry device with an upstream liquid chromatography system. The obtained raw data were analyzed using the Maxquant proteome software and compared. Proteins with a fold-change ratio higher than a cut-off of 2 were considered as noticeably altered.RESULTS: A total number of 175 proteins could be identified out of the AH from POAG and cataract by means of quantitative mass spectrometric analysis. Apolipoprotein D(fold change, 3.16 times), complement C3(2.96), pigment epithelium-derived factor(2.86), dickkopf-related protein 3(2.18) and wingless-related integration(Wnt) inhibitory factor 1(2.35) were significantly upregulated within the AH of glaucoma compared to cataract serving as controls.CONCLUSION: AH provides a tool to analyze changes in glaucoma and shows striking changes in Wnt signaling inhibitory molecules and other proteins.

葡萄膜炎继发性青光眼与其他难治性青光眼Ahmed青光眼引流阀植入后前房反应的非随机对照研究

背景 葡萄膜炎继发性青光眼患者由于葡萄膜的炎症而导致血-房水屏障的破坏,局部手术的创伤刺激可加重炎症反应,对术眼前房炎症反应进行定量检测可监测眼部反应程度. 目的 探讨葡萄膜炎继发性青光眼患者行Ahmed青光眼引流阀植入术后前房内炎症反应是否重于其他类型的难治性青光眼.方法 采用前瞻性非随机对照的病例对照研究方法,于2011年10月至2012年7月纳入在中山大学中山眼科中心确诊的难治性青光眼29例29眼,分为葡萄膜炎继发性青光眼组（10眼）及其他类型的难治性青光眼组（19眼）,2个组间术眼术前性别、年龄、眼压及房水闪辉值等基线特征匹配.所有患者均接受Ahmed房水引流阀植入术并随访3个月,记录术前、术后1d、3d、1周、2周、1个月和3个月术眼的眼压,同时采用FC-2000激光蛋白细胞检测仪定量测定术眼的房水闪辉值,以光粒子数/ms表示.比较2个组间房水引流阀植入术后房水闪辉值的不同,对术眼手术前后眼压值变化与房水闪辉值变化的关系进行分析. 结果 葡萄膜炎继发性青光眼组术后1d、3d和1周房水闪辉值分别为[21.10 （10.50,38.58）]、[88.00（23.55,168.63）]和[29.90（8.90,65.18）]光粒子数/ms,均明显高于术前的[13.53（7.60,24.00）]光粒子数/ms,差异均有统计学意义（均P＜0.01）,术后1个月和3个月房水闪辉值分别为[6.45 （4.70,13.50）]光粒子数/ms和[8.95 （6.23,18.20）]光粒子数/ms,均低于术前值,差异均有统计学意义（均P＜0.01）;其他类型青光眼组遵循同样的趋势.术后3个月葡萄膜炎继发性青光眼组术眼房水闪辉值明显高于其他类型青光眼组,差异有统计学意义（q=-3.445,P＜0.01）.术后2个组间眼压的比较差异无统计学意义（P＞0.05）.所有患者术眼术后眼压值均逐渐下降,术前及术后1d、3d、1周、2周、1个月和3个月术眼眼压与前房闪辉值间均无明显相关性（rs =0.136,P=0.481;rs=0.019,P=0.922;rs =-0.035,P=0.858;r,=0.317,P=0.094;rs=0.034,P=0.861;rs=-0.094,P=0.628;rs=0.065,P=0.738）. 结论 FC-2000激光蛋白细胞检测仪检测证实Ahmed房水引流阀植入术可导致术眼术后早期的前房炎症反应,葡萄膜炎继发性青光眼患者术后炎症反应的恢复较缓慢,术后3个月时房水闪辉值仍高于其他类型的难治性青光眼.

MicroRNAs as biomarkers in glaucoma and potential therapeutic targets

Glaucoma is a neurodegenerative disease in which optic nerve damage and visual field defects occur.It is a leading cause of irreversible blindness.Its pathogenesis is largely unknown although several risk factors have been identified,with an increase in intraocular pressure being the main one.Lowering of intraocular pressure is the only treatment available.Open-angle glaucoma is the most common form of the condition,accounting for~90%of all cases of glaucoma,with primary open-angle glaucoma and exfoliation glaucoma being the most frequent types.There are strong indications that microRNAs play important roles in the pathogenesis of primary open-angle glaucoma.Most of the recent studies reviewed had performed microRNA profiling in aqueous humor from glaucoma patients compared to controls who were chiefly cataract patients.A very large number of microRNAs were dysregulated but with limited overlap between individual studies.MiRNAs in aqueous humor that could be possible targets for therapeutic intervention are miR-143-3p,miR-125b-5p,and miR-1260b.No ove rlap of findings occurred within the dysregulated miRNAs for blood plasma,blood serum,peripheral blood mononuclear cells,and tears of primary open-angle glaucoma patients.Seve ral impo rtant limitations were identified in these studies.Further studies are warranted of mic roRNA expression in aqueous humor and blood samples of primary open-angle glaucoma patients in the early stages of the disease so that validated biomarkers can be identified and treatment initiated.In addition,whether modifying the levels of specific microRNAs in aqueous humor or tears has a beneficial effect on intraocular pressure and ophthalmic examination of the eyes should be investigated using suitable animal models of glaucoma.

Intraocular pressure control of a novel glaucoma drainage device-in vitro and in vivo studies

AIM：To evaluate the intraocular pressure（IOP）control of an artificial trabeculum drainage system（ATDS）,a newly designed glaucoma drainage device,and postoperative complications in normal rabbit eyes.METHODS：Pressure drops in air and fluid of 30 ATDS were measured after being connected to a closed manometric system.Twenty of them were then chosen and implanted randomly into the eyes of 20 rabbits.Postoperative slitlamp,gonioscopic examination and IOP measurements were recorded periodically.Ultrasound biomicroscopy and B-scan ultrasonography were also used to observe the complications.Eyes were enucleated on day 60.RESULTS：Pressure drops of 4.6-9.4 mm Hg were obtained at physiological aqueous flow rates in the tests in vitro.The average postoperative IOP of the experimental eyes（11.6-12.8 mm Hg）was lower than the controls significantly（P〈0.05）at each time point.Complications of hemorrhage（n=1）,cellulosic exudation（two cases）and local iris congestion（two cases）were observed.The lumina of the devices were devoid of obstructions in all specimens examined and a thin fibrous capsule was found around the endplate.CONCLUSION：ATDS reduce IOP effectively.However,further studies on the structure are needed to reduce complications.

Analogs of microgravity: the function of Schlemm's canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects

AIM:To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure(IOP)change following the head-down tilt(HDT)test.METHODS:The study included 21 participants at the Department of Ophthalmology of Tongji Hospital.Subjects received the test of I-care tonometry,enhanced depth imaging optical coherence tomography and heart rate variability(HRV)analysis before and after 15 min HDT test.The lumen area of Schlemm’s canal(SCAR),IOP,HRV were calculated.RESULTS:IOP increased significantly after 20°head down position from 14.0±3.0 to 17.0±3.3 mm Hg(P<0.001).SCAR decreased from 13449.0±5454.9μm^(2) at sitting condition to 9576.6±4130.9μm^(2) post 15 min HDT test.High frequency(HF)indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz.Heart rate(HR)decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT.The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT(R^(2)=20%,P=0.04).CONCLUSION:These outcomes perform the first evidence of the activation of autonomic nervous system of HDT may cause the collapse of Schlemm’s canal lumen,which in turn leading to the increased IOP.

Lessons from glaucoma: rethinking the fluid-brain barriers in common neurodegenerative disorders

Glaucoma has been recently characterized as a member of the group of anoikis-related diseases. Anoikis, a form of apoptosis, can be triggered by the unfastening of adherent junctions present in astrocytes. In those areas of the central nervous system in which the soma of the neurons or their axons and dendrites are metabolically dependent on the activity of astrocytes, a derangement of the lactate shuttle caused by a separation between the plasma membranes of neurons and astrocytes would result in metabolic impairment of the neurons themselves. In glaucoma, the triggering event has been attributed to the posterior deviation of aqueous humor towards the astrocyte-rich prelaminar tissue of the optic nerve head. The mean calcium content in the aqueous is able to interfere with calcium-dependent adherent junctions and induce anoikis of the astrocytes. As the cerebrospinal fluid has a similar base calcium concentration, a shunt of cerebrospinal fluid through the cerebral parenchyma would be able to interfere in the astrocytic architecture with dire consequences to the metabolically dependent neurons. Here the similitude between glaucoma,amyotrophic lateral sclerosis and Alzheimer's disease are discussed and the concept of the break in the fluid-brain barrier, as an event separated from the blood-brain barrier, is stressed.

Hepcidin Prohormone Levels in Patients with Primary Open-Angle Glaucoma

Aims: To assess the levels of hepcidin prohormone (Hep) in aqueous humor and plasma of human eyes with primary open-angle glaucoma (POAG) and to correlate their concentrations with the severity of glaucoma. Methods: Sixty patients with POAG and forty five patients with senile cataract (control group) were enrolled in the study prospectively. Aqueous humor samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous humor and?corresponding plasma samples were analyzed for Hep concentrations by enzyme-linked immunosorbent assay. Results: Hep levels were significantly lower in aqueous humor of POAG patients with respect to the comparative group of cataract patients (P < 0.001). No significant difference in the levels of Hep in plasma of POAG and cataract patients. A positive correlation was found between plasma/aqueous humor Hep concentration in POAG versus the control group (P < 0.001). No significant correlation was found between Hep levels and the severity of visual field loss. Conclusion: Lower levels of aqueous humor Hep may be associated with POAG. In addition, Hep may be useful protein derivatives levels in aqueous humor of POAG patients as a consequence of glaucomatous damage.

Risk factors for the long-term prognosis and recurrence of HIV-negative cytomegalovirus retinitis in North China

AIM: To demonstrate the clinical features, the risk factors, the visual prognosis and the recurrence of cytomegalovirus(CMV) retinitis(CMVR) in HIV-negative patients.METHODS: HIV-negative patients with CMVR were involved in this study. Best corrected visual acuity(BCVA), intraocular pressure(IOP), CMV-DNA load in aqueous and/or serum samples, treatment, follow-up time, recurrence and complications were recorded. Ocular characteristics were evaluated by fundus photographs. Association between ocular factors and visual prognosis were analyzed by regression analysis.RESULTS: Twenty-five eyes of 16 patients were included. All 25 eyes underwent intravitreal injections of anti-viral agents. The mean log MAR BCVA improved from 0.94±0.98(0.98-0.78) initially to 0.77±0.73(0.82-0.68) at last visit, but not significantly. After antiviral treatment, the aqueous CMV DNA load significantly reduced to(3.42±1.47)×10~2 copies/m L(P=0.001), compared with(2.51±3.11)×10~5 copies/m L at baseline. Macular involvement(R~2=0.475, P=0.049) and initial visual acuity(R~2=0.475, P=0.017) were significantly associated with the poor visual prognosis(BCVA<20/400). The extent of retinal lesions(R~2=0.064, P=0.04) was significant associated with the risk of recurrence of CMVR.CONCLUSION: Intravitreal injection of anti-viral agents offers a safe and effective treatment for CMVR. Macular involvement and initial visual acuity significantly associate with visual prognosis. The extent of retinal lesions is significantly associated with the recurrence of CMVR. These ocular factors can be used as predictive risk factors for long term visual prognosis in HIV-negative CMVR patients.

Extracellular matrix gene expression in human trabecular meshwork cells following mechanical fluid flow stimulation

AIM: To investigate changes in extracellular matrix(ECM) gene expression in human trabecular meshwork(HTM) cells in response to mechanical fluid flow stimulation.METHODS: HTM cells were grown on a glass plate coated with 0.02% type Ⅰ collagen(COL) and exposed to shear stress(0, 0.2, 1.0 dyne/cm;) for 12 h.Changes in genes related to the ECM were evaluated by real-time reverse transcriptase-polymerase chain reaction.Phosphorylation of Smad2 protein was investigated by Western blotting.RESULTS: After mechanical stimulation, COL type 4 alpha 2, COL type 6 alpha 1, and fibronectin-1 mRNA were significantly higher than the static control(P<0.05, <0.05, and <0.01, respectively).The metalloproteinase-2 and plasminogen activator inhibitor-1 mRNA were significantly higher than the static control(P<0.05 and <0.01, respectively), while the differences in the tissue inhibitors of metalloproteinases-2 mRNA were not significant.The phosphorylation of Smad2 levels was significantly higher compared to the static control cells.CONCLUSION: Changes in the expressions of genes associated ECM metabolism result in HTM cells after mechanical stimulation.The mechanical stimulation of the aqueous humor to the trabecular meshwork may promote ECM turnover and contribute to intraocular pressure homeostasis.