Research and Realization of a Master-Slave Robotic System for Retinal Vascular Bypass Surgery

Retinal surgery continues to be one of the most technical demanding surgeries for its high manipulation accuracy requirement, small and constrained workspace, and delicate retinal tissue. Robotic systems have the potential to enhance and expand the capabilities of surgeons during retinal surgery. Thus, focusing on retinal vessel bypass surgery, a master-slave robot system is developed in this paper. This robotic system is designed based on characteristics of retinal vascular bypass surgery and analysis of the surgical workspace in eyeball. A novel end-effector of two degrees of freedom is designed and a novel remote center of motion mechanism is adopted in the robot structure.The kinematics and the mapping relationship are then established, the gravity compensation control strategy and the hand tremor elimination algorithm are applied to achieve the high motion accuracy. The experiments on an artificial eyeball and an in vitro porcine eye are conducted, verifying the feasibility of this system.

Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus

AIM：To compare the effectiveness and safety between modified cross-linking（MC）and standard cross-linking（SC）in mild or moderate progressive keratoconus.METHODS：Eligible studies were retrieved from four electronic databases,including CENTRAL,Clinical Trials gov,Pup Med and OVID MEDLINE.We set post-surgical maximum K value（Kmax）as the primary outcome.In addition,uncorrected and corrected distant visual acuity（UDVA and UDVA）,spherical equivalent（SE）,endothelial cell density（ECD）,central cornea thickness（CCT）and depth of demarcation line（DDL）were Meta-analyzed as secondary outcomes.Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity.RESULTS：Twenty-four comparative studies either on accelerated cross-linking（AC）compared with SC or on transepithelial cross-linking（TC）compared with SC were included and pooled for analysis.The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration[AC vs SC 0.49（95%CI：0.04-0.94,I2=75%,P=0.03）;TC vs SC 1.15（95%CI：0.54-1.75,I2=50%,P=0.0002）].SE decreased significantly for SC when compared to AC[0.62（95%CI：0.38-0.86,I2=22%,P〈0.00001）].DDL of SC was more significantly deeper than that of TC[-133.49（95%CI：-145.94 to-121.04,I2=33%,P〈0.00001）].Other outcomes demonstrated comparable results between MC and SC.CONCLUSION：SC is more favorable at halting the progression of keratoconus,but visual acuity improvement showed comparable results between MCs and SC.

Progress in the basic and clinical research on the Schlemm’s canal

Glaucoma is a leading cause of irreversible blindness in the world.Intraocular pressure(IOP)plays a key role in glaucoma development and progression.Schlemm’s canal(SC),an important structure of the anterior chamber angle,regulates the flow of aqueous humor and maintains IOP.Because of its special function of aqueous outflow,the SC has been intensive investigated recently.Several characteristics of SC in anatomy,physiology and pathophysiology have been revealed.Compare to normal,glaucomatous SC cells are more sensitive to substrate stiffness,have higher stiffness and and lower porosity leading to higher outflow resistance.And SC collapse caused by acute IOP increase is partially or totally reversal.With advanced inspection techniques,high-quality images of the SC can be obtained in vivo,which facilitates SC quantitative measurements clinically and allows us to investigate a new therapy paradigm for glaucoma.In this review,we summarize the basic and clinical research that focused on mechanisms of aqueous outflow resistance and SC changes in physiological,pathological,and posttreatment states.

Exploration of action mechanisms of Resina Draconis(Daemonorops draco Bl.)against pain by network pharmacology and molecular docking analysis

Background:Resina Draconis is a traditional Chinese medicine mainly used to treat pain.However,the pharmacological mechanisms and chemical composition of Resina Draconis are not clear yet.Methods:In this study,based on the 21 main active components of Resina Draconis previously analyzed by our group,the potential action targets of the active components were predicted and screened out by using the databases such as Swiss Target Prediction and Pharmapper.The genes corresponding to the related targets were retrieved by UniProt and GeneCards,and then the"component-target"network model was established using Cytoscape 3.9.1 software.The protein-protein interaction network was constructed by using STRING database for analysis.The STRING database was used for enrichment analysis of gene ontology and Kyoto Encyclopedia of Genes and Genome pathways to explore the underlying action mechanisms.Result:A total of 21 main analgesic active components of Resina Draconis and 77 intersecting targets of Resina Draconis and pain were screened out.PPI network analysis indicated that such targets as albumin(ALB),tumor necrosis factor(TNF),RAC-alpha serine/threonine-protein kinase 1(AKT1)and epidermal growth factor receptor(EGFR)might be the core targets of analgesia.Through gene ontology enrichment analysis,a total of 169 gene ontology entries were obtained(P<0.01),including 111 biological processes,31 molecular functions and 27 cellular components.Through enrichment analysis of KEGG pathways,a total of 112(P<0.01)signaling pathways were screened.Conclusion:Dracaenogenins A,Resveratrol and 7,4′-dihydroxyflavone in Resina Draconis may be the main material basis for analgesia,which can interact with multiple targets such as AlB,AKT1,TNF,and EGFR,and exerts analgesic effect through signaling pathways such as mitogen-activated protein kinase(MAPK)signaling pathway,PI3K-Akt signaling pathway,and Rap1 signaling pathway.

Current Research of Chlamydial Infection Diseases in China

To the Editor： Cblam.~zti^t organisms belong to intracellular bacterial pathogens which are responsible for a range of human diseases, including trachoma, sexually transmitted disease, pneumonia, and other diseases. Some Chlamydia-infected diseases were old and had long time impacted on the people＇s health in China and worldwide, but people cannot put enough emphasis on it in local areas.