The Early Mesozoic NE-SW Extensional Model and Exhumation Processes at the Southeastern Margin of the Central Asian Orogenic Belt:Insights from the Strain and Kinematic Vorticity Analysis of the Sonid Zuoqi Ductile Detachment Zone

The Sonid Zuoqi ductile detachment zone is located at the southeastern margin of the Central Asian orogenic belt(CAOB),striking EW and dipping to the S.The major rock type of the Sonid Zuoqi ductile detachment zone is mylonite derived from granite.The sequence of mylonite features is:(1)S and C foliations of mylonite,and(2)extensional crenulation cleavage(ecc)or C′and the kinematic vorticity(Wk)value changed from 0.70 to 0.95 and from 0.37 to 0.69,respectively;the strain type of the mylonites within the Sonid Zuoqi ductile detachment zone is compressional to planar strain.The strong deformation mylonite and Halatu plutons yielded a zircon U-Pb age of 244 Ma and a zircon(U-Th)/He age of 214 Ma,respectively.Based on the strain and kinematic vorticity analysis,together with the zircon U-Pb and zircon(U-Th)/He ages and the regional tectonic background,the study area experienced three stage evolution:tangential simpleshear(244 Ma),simple-shear-dominated general shear represented by upper crustal extension(224 Ma)and pure-shear-dominated general shear represented by the Halatu pluton doming(214 Ma),which constrained the early Mesozoic NE-SW crustal extension at the southeastern margin of the CAOB.This NE-SW extension probably originated from the postorogenic extensional collapse of the CAOB,subsequent exhumation being controlled by the far afield effects of the closure of the Mongol-Okhotsk belt.

Calculation and prediction of divertor detachment via impurity seeding by using one-dimensional model

Achieving the detachment of divertor can help to alleviate excessive heat load and sputtering problems on the target plates,thereby extending the lifetime of divertor components for fusion devices.In order to provide a fast but relatively reliable prediction of plasma parameters along the flux tube for future device design,a one-dimensional(1D)modeling code for the operating point of impurity seeded detached divertor is developed based on Python language,which is a fluid model based on previous work(Plasma Phys.Control.Fusion 58045013(2016)).The experimental observation of the onset of divertor detachment by neon(Ne)and argon(Ar)seeding in EAST is well reproduced by using the 1D modeling code.The comparison between the 1D modeling and two-dimensional(2D)simulation by the SOLPS-ITER code for CFETR detachment operation with Ne and Ar seeding also shows that they are in good agreement.We also predict the radiative power loss and corresponding impurity concentration requirement for achieving divertor detachment via different impurity seeding under high heating power conditions in EAST and CFETR phase II by using the 1D model.Based on the predictions,the optimized parameter space for divertor detachment operation on EAST and CFETR is also determined.Such a simple but reliable 1D model can provide a reasonable parameter input for a detailed and accurate analysis by 2D or three-dimensional(3D)modeling tools through rapid parameter scanning.

Pars plana vitrectomy for retinal detachment using perfluoro-n-octane as intraoperative tamponade:a multicenter,randomized,non-inferiority trial

AIM:To evaluate the efficacy and safety of perfluoro-n-octane(PFO)for ophthalmic surgery versus F-Octane as an intraoperative tamponade in pars plana vitrectomy(PPV)in management of retinal detachment.METHODS:This multicenter,prospective,randomized,double-masked,parallel-controlled,non-inferiority trial was conducted in three ophthalmology clinical centers in China.Patients with retinal detachment,who were eligible for PPV were consecutively enrolled.Participants were assigned to PFO for ophthalmic surgery or F-Octane for intraocular tamponade in a 1:1 ratio.Best-corrected visual acuity(BCVA),intraocular pressure(IOP)measurement,and dilated fundus examination were performed preoperatively and at 1,7±1,28±3d postoperatively.The primary outcome was complete retinal reattachment rate at postoperative day one.The non-inferiority margin was set at 9.8%.The secondary outcomes included intraoperative retinal reattachment rate,and mean changes in IOP and BCVA from baseline to 1,7±1,28±3d postoperatively,respectively.Safety analyses were presented for all randomly assigned participates in this study.RESULTS:Totally 124 eligible patients completed the study between Mar.14,2016 and Jun.7,2017.Sixty of them were randomly assigned to the PFO for ophthalmic surgery group,and 64 were assigned to the F-Octane group.Baseline characteristics were comparable between the two groups.Both groups achieved 100%retinal reattachment at postoperative day one(difference 0,95%CI:-6.21%to 5.75%,P=1).The pre-defined noninferiority criterion was met.No significant difference was observed in intraoperative retinal reattachment rate(difference 1.77%,P=0.61),mean changes in IOP(difference 0.36,-0.09,2.22 mm Hg at 1,7±1,28±3d postoperatively,with all P>0.05)and BCVA(difference 0.04,-0.02,0.06 logMAR at 1,7±1,28±3d postoperatively,all P>0.05)between the two groups.No apparent adverse events related to the utilization of PFO were reported.CONCLUSION:In patients with retinal detachment undergoing PPV,PFO for ophthalmic surgery is non-inferior to F-Octane as an intraocular tamponade,and both are safe and well-tolerated.

Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases:A prospective,blind clinical study

BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases.

Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oilfilled eyes

AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.METHODS:Totally 9 patients(9 eyes)with retinal detachment in SO-filled eyes were retrospectively analyzed.All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination.SO was removed at an appropriate time based on recovery.The patients were followed up for at least 3mo after SO removal.Retinal reattachment,complications,visual acuity and intraocular pressure(IOP)before and after surgery were observed.RESULTS:Patients were followed up for a mean of 8.22mo(3-22mo)after SO removal.All patients had retinal reattachment.At the final follow-up,visual acuity showed improvement for 8 patients,and no change for 1 patient.The IOP was high in 3 patients before surgery,but it stabilized after treatment;it was not affected in the other patients.None of the patients had infections,hemorrhage,anterior ischemia,or any other complication.CONCLUSION:This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes.

A finite element model of the eye matched with in vitro experiments for the prediction of traumatic retinal detachment

This study aimed to conduct finite element(FE)analysis matched with an in vitro experiment to analyze traumatic retinal detachments(TrRD)resulting from blunt trauma and provide stress and strain thresholds to predict the occurrence of TrRD.The in vitro experiment was performed on forty-eight porcine eyes using a pendulum device.We examined dynamic mechanical responses at four energy levels.A FE model,based on experimental results and published data,was used to simulate TrRD.Fifty-one additional eyes underwent immediate pathological examination following blunt impact.A dynamic variation of velocities was observed post-impact,displaying an approximate cosine oscillation-attenuation profile.Energy absorption increased as the initial energy and differed significantly at four energy levels(p<0.001).FE simulation showed a peak strain of 0.462 in the anterior vitreous body and a peak stress of 1.408 MPa at the cornea at the high-energy level.During the energy transfer,the stress was initially observed in retinal region along the impact direction at the separation.TrRD were observed in injured eyes,where a few detachments were detected in control eyes.Correlations were performed between the proportion of pathological outcomes and FE results.In conclusion,this study suggests that stress contributes to the development of retinal detachment,providing an indicator to distinguish the occurrence of TrRD.

Efficacy of scleral buckling for the treatment of rhegmatogenous retinal detachment using a novel foldable capsular buckle

●AIM:To evaluate the effectiveness and safety of scleral buckling for the treatment of rhegmatogenous retinal detachment(RRD)using a novel foldable capsular buckle(FCB).●METHODS:This was a series of case observation studies.Eighteen patients(18 eyes)who visited our ophthalmology department between August 2020 and August 2022 and were treated for RRD with scleral buckling using FCB were included.The procedure was similar to conventional scleral buckling,while a balloon-like FCB was placed onto the retinal break with balanced salt solution filling for a broad,external indentation instead of the silicone buckle.The retinal reattachment rate,best corrected visual acuity(BCVA),intraocular pressure(IOP),refractive dioptre and astigmatism degree,and complications were evaluated and recorded.●RESULTS:There were 7 males and 11 females aged 19-58y.The average time course of RRD was 12d,ranging from 7-20d.The retinal break was located in the superior quadrants in 8 eyes and in the inferior quadrants in 10 eyes,with macula-off detachments in 12 eyes.The patients were followed-up for at least 6mo.The final retinal reattachment rate was 100%.The BCVA was significantly improved compared with the baseline(P<0.05).There was no significant change in refractive dioptre or astigmatism degree at each follow-up(all P>0.05).Three patients had transiently high IOPs within one week after surgery.Mild diplopia occurred in 5 patients after surgery and then disappeared after the balloon fluid was removed.●CONCLUSION:The success rate of FCB scleral buckling for RRD is satisfactory.This procedure can be expected to be applied in new,uncomplicated cases of RRD.

Rhegmatogenous retinal detachment in highly myopic eyes with implantable collamer lens

AIM:To investigate the clinical characteristics,treatment methods and outcomes of rhegmatogenous retinal detachment(RRD)in highly myopic eyes with implantable collamer lens(ICL).METHODS:High myopia patients who received treatment for nontraumatic RRD after ICL implantation surgery at the Retinal Department of Zhongshan Ophthalmic Center from Jan 2018 to Dec 2022 were reviewed.Comprehensive ophthalmologic examinations including visual acuity measurement and digital fundus photography were performed in each patient.RESULTS:A total of nine RRD eyes from nine patients who received V4c-ICL implantation were included.The mean time from ICL implantation surgery to the diagnosis of RRD was 32.44±22.56mo(range,1-60mo).At the initial visit for RRD,giant retinal tear(GRT),horseshoe tear,simple round hole,and horseshoe tear combined with round hole were detected in 3,3,2,and 1 eye(s),respectively,with maculaoff in eyes.Eight patients received surgical treatment,and one patient was treated by retinal laser photocoagulation alone.The ICL was preserved in 7 eyes.At the last followup,the mean best corrected visual acuity(BCVA)improved significantly from 1.76±1.06 logMAR at presentation to 0.81±1.01 logMAR(P=0.035),and no case of recurrent retinal detachment was found.CONCLUSION:The morphological presentation of retinal breaks is diverse in this study.The ICL can be preserved in most cases during the course of retinal detachment repair surgery in our data,companied with acceptable visual and anatomical outcomes.

Left atrial appendage occluder detachment treated with transthoracic ultrasound combined with digital subtraction angiography guided catcher:A case report

BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.

Pseudoaneurysm formation following transarterial embolization of traumatic carotid-cavernous fistula with detachable balloon:An institutional cohort long-term study

BACKGROUND The goal of therapy for traumatic carotid-cavernous fistula(TCCF)is the elimination of fistula while maintaining patency of the parent artery.The treatment for TCCF has evolved from surgery to endovascular management using detachable balloons,coils,liquid embolic agents,covered stents,or flow-diverter stent through arterial or venous approaches.Despite the withdrawal of detachable balloons from the market in the United States since 2004,transarterial embolization with detachable balloons has currently remained the best initial treatment for TCCF in several countries.However,the pseudoaneurysm formation following transarterial detachable balloon embolization has rarely been observed in long-term follow-up.AIM To determine the occurrence and long-term follow-up of pseudoaneurysm after transarterial detachable balloon for TCCF.METHODS Between January 2009 and December 2019,79 patients diagnosed with TCCF were treated using detachable latex balloons(GOLDBAL)of four sizes.Pseudoaneurysm sizes were stratified into five grades for analysis.Initial and follow-up assessments involved computed tomography angiography at 1 month,6 month,1 year,and longer intervals for significant cases.Clinical follow-ups occurred semi-annually for 2 years,then annually.Factors analyzed included sex,age,fistula size and location,and balloon size.RESULTS In our cohort of 79 patients treated for TCCF,pseudoaneurysms formed in 67.1%,with classifications ranging from grade 0 to grade 3;no grade 4 or giant pseudoaneurysms were observed.The majority of pseudoaneurysms did not progress in size,and some regressed spontaneously.Calcifications developed in most large pseudoaneurysms over 5-10 years.Parent artery occlusion occurred in 7.6%and recurrent fistulas in 16.5%.The primary risk factors for pseudoaneurysm formation were identified as the use of specific balloon sizes,with balloon SP and No.6 significantly associated with its occurrence(P=0.005 and P=0.002,respectively),whereas sex,age,fistula size,location,and the number of balloons used were not significant predictors.CONCLUSION Pseudoaneurysm formation following detachable balloon embolization for TCCF is common,primarily influenced by the size of the balloon used.Despite this,all patients with pseudoaneurysms remained asymptomatic during long-term follow-up.

Detached Eddy Simulation方法模拟不同类型翼型的失速特性

应用DES(DetachedEddySimulation)方法数值模拟了3种不同失速类型的翼型的升力特性。DES方法结合了RANS(ReynoldsaveragedNavierStokes)和LES(LargeEddySimulationapproaches)的优点。基于SpalartAllmaras湍流模型,在近壁面DES体现为RANS模型的特点而在远离物面处又具有LES的亚格子模型的特性。对此模型使用了LUSGS隐式格式求解。通过和实验结果对比,显示这种方法可以有效地预测翼型的失速特性。

Effects of static magnetic fields on melt flow in detached solidification

A series of three-dimensional numerical computations were conducted to understand the effects of different static magnetic fields on thermal fluctuation and melt flow during the detached solidification of CdZnTe. Numerical calculations were carried out by three different configurations of magnetic field: without magnetic field, with an axial magnetic field (AMF) and with a cusp-shaped magnetic field (CMF). The results reveal that the magnetic fields can effectively suppress the melt flow and thermal fluctuation and the suppression effect of the AMF is stronger than that of the CMF. Besides, the physical mechanism of thermocapillary?buoyancy convection instability was discussed and the effects of magnetic field on the critical Marangoni number were also obtained.

Vitrectomy, lensectomy and silicone oil tamponade in the management of retinal detachment associated with choroidal detachment

AIM: To report the results of combined vitrectomy, lensectomy and silicone oil (SO) tamponade in treating primary rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). · METHODS: A retrospective, consecutive and case series study of 21 subjects with concurrent RRD associated with CD was conducted. All subjects underwent a standard three -port 20G pars plana vitrectomy (PPV) with lensectomy and silicone oil tamponade. Mean follow -up time was 8 months (rang from 4 to 19 months). The primary and final anatomic success rate, visual acuity and final intraocular pressure (IOP) were recorded and analyzed. ·RESULTS: Of 21 subjects, 8 were women and 13 were men. Age at presentation ranged from 22 to 75 years (mean 57.4 years). The presenting vision ranged from light perception to 0.15. The initial IOP ranged from 3mmHg to 12mmHg (mean 6.2mmHg). All eyes were phakic except one pseudophakic. No intraocular lens was implanted during the primary surgical intervention. Fifteen of 21 (71.4%) eyes had retina reattached after one operation. Six eyes had recurrent inferior retinal detachment due to proliferation. Five of them were successfully reattached after one or more additional operations. Mean IOP at final follow -up was 15.2mmHg (range from 8mmHg to 20mmHg). One case declined for further operation. The final reattachment rate was 95.2%. Visual acuity improved in 19 (90.5%) eyes, was unchanged in 1 (4.8%) eye and decreased in 1 (4.8%) eye.·CONCLUSION: Combination of vitrectomy, lensectomy and silicone tamponade is an effective method in treating RRD associated with CD, reducing the incidence of postoperative hypotony.

Risk factors of rhegmatogenous retinal detachment associated with choroidal detachment in Chinese patients

AIM： To comprehensively analyze the risk factors of rhegmatogenous retinal detachment （RRD） associated with choroidal detachment （CD）. METHODS： A total of 265 eyes of 265 consecutive cases of RRD were retrospectively analyzed. All patients had systemic and ophthalmologic examination. CD was diagnosed by indirect ophthalmoscopy, B -scan ultrasonography, and ultrasound biomicroscope （UBM）. Each parameter was compared between patients of RRD and rhegmatogenous retinal detachment associated with choroidal detachment （RRDCD）. Logistic regression analysis was used to determine the independent risk factors of CD. RESULTS： There were 52 eyes （19.62%） with CD. Pseudophakia was more commonly seen in RRDCD （21.15% ys6.10%, P=0.002）. Intraocular pressure （lOP） was lower （8.60 ±3.62 ys 12.96 ±3.55, P 〈0.001）, best - corrected visual acuity was worse [3.00 （2.00 to 3.00） vs 1.92 （1.22 to 3.00）, P=-0.001], and refractive error was more myopic [-4 （-9 to -2） vs -2 （-6 to 0）, P=0.007] in RRDCD. Eyes with RRDCD had larger extent of retinal detachment （P=0.007）. In RRDCD, 34.62% of eyes presented with multiple holes （P=0.044） and 25.00% with macular holes （P=0.012）, compared with 20.66% and 14.08% in R RD. High myopia （P=0.039）, low lOP （P=0.017）, and larger extent of retinal detachment （P〈0.001） were significant and independent risk factors for developing CD. - CONCLUSION： For CD in RRD, related factors include BCVA, lOP, lens status, refractive error, extent of retinal detachment, number of holes, and macular hole. Larger extent of retinal detachment, high myopia, and low lOP are significant and independent risk factors.

STUDY ON SLAG DETACHABILITY AND STICK SLAG MECHANISM OF SSFCE

In the paper, the effects of linear expansion coefficient and basic index of melting slag on the detachability of self shielded flux cored electrode (SSFCE) are investigated. An equation is obtained on the principles of ceramics and mineralography which predict the detachability of basic SSFCE. In addition, stick slag mechanism of SSFCE is analyzed.

Multi-level Detachments and Petroleum Potential of the Tarim Basin

Four detachment systems have been found in the Tarim Basin. They are made up of the Proterozoic,Palaeozoic, Mesozoic-Eogene and Neogene-Quaternary, respectively. The shallow-level detachments are char-acterized by the occurrence of fold-thrust belts in the Meso-Cenozoic. The mid-level detachments are markedby nappes, decollement folds and drag anticlines in the Palaeozoic. The deep-level detachments are representedby ductile shear belts in the basement. Mid-and deep-level detachments mainly occur in the Northern, Centraland Southern Uplifts which are major hydrocarbon accumulation belts of large-scale oil fields. Shallow-leveldetachments mainly exist in the Kuqa, Southwestern and Southeastern Depressions, which are favourable beltsfor finding medium- and small-sized oil-gas fields.

Paediatric retinal detachment:a review

Paediatric retinal detachment（PRD）is an uncommon and challenging disease;it differs from adult detachments in etiology,anatomical characteristics,management and prognosis.PRDs can be particularly challenging,even for the most expert paediatric surgeons due to the higher prevalence of total retinal detachments,late diagnosis and bilateral involvement with respect to those which occur in adulthood.Moreover,the anatomical success,when achieved,is frequently not related to a functional recover.Postsurgical adverse events,refractive errors and amblyopia may additionally undermine the final outcome.Up to date there are few reviews regarding the approach of retinal detachment in children,mainly dealing with rhegmatogenous retinal detachment.In this review,rhegmatogenous,retinopathy of prematurityrelated and Coats’-related PRDs were considered.The available literature from the last decades were reviewed and summarized.Epidemiology,etiology and clinical presentation,together with therapeutic approaches and outcomes have been reviewed and discussed.

Structural Traps in Detachment Folds:a Case Study from the 'Comband Trough-like' Deformation Zone/s,East Sichuan,China

Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ＇comb-like＇ and ＇toughlike＇ fold belts in eastern Sichuan are caused by multi-layer detachment. The duplex structure is the most important deformation style in the region, exhibiting different characteristics from typical detachment structures. Different deformation styles, scales, and shortenings resulting from independent deformations of various detachment systems would lead to the phenomenon whereby most of the topographical heights in the region do not correspond to the structural heights in depth. Based on systematic structural analysis and combined with practical oil/gas prospecting, four types of structural traps are described from eastern Sichuan Province, which are： detachment and thrust trap; detachment folding trap; fault-flat blocking trap; and detachment layer trap. Meticulous studies on the deformation and distribution of detachment layers in the eastern Sichuan Province will contribute to oil/gas prospecting and selection of potential regions of marine-origin oil/gas prospecting in South China.

Primary 23-gauge vitreoretinal surgery for rhegmatogenous retinal detachment

AIM: To report the effectiveness and safety of primary 23-Gauge (G) vitreoretinal surgery for rhegmatogenous retinal detachment (RRD). · METHODS: In this retrospective study, 49 eyes of 49 consecutive patients who underwent primary 23-G transconjunctival sutureless vitrectomy (TSV) for RRD between January 2007 and July 2009 at our institution were evaluated. · RESULTS: Mean follow-up time was 8.9±7.7 months (1-28 months). Retinal reattachment was achieved with a single operation in 47(95.9%) of 49 eyes. In two eyes (4.1%), retinal redetachment due to new breaks was successfully treated with reoperation using the 23-G TSV system. Mean logMAR visual acuity was 2.01±0.47 preoperatively and 1.3±0.5 postoperatively (P <0.001, Paired t -test). Mean preoperative intraocular pressure (IOP) was 14.1±2.8mmHg. Mean postoperative IOP was 12.3±3.6mmHg at 1 day, 13.1±2.1mmHg at 1 week, 14.3±2.2mmHg at 1 month. Iatrogenic peripheral retinal break was observed in 1 eye(2.0%) intraoperatively. No sutures were required to close the scleral or conjunctival openings, and no eyes required convertion of surgery to 20-G vitrectomy. · CONCLUSION: Primary 23-G TSV system was observed to be effective and safe in the treatment of RRD.

Missed retinal breaks in rhegmatogenous retinal detachment

AIM： To evaluate the causes and associations of missed retinal breaks（MRBs） and posterior vitreous detachment（PVD） in patients with rhegmatogenous retinal detachment（RRD）.METHODS： Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and191 patients were included for analysis of PVD,depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations.RESULTS： Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs（P =0.033） with the odds of missing a retinal break being1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy（PVR） and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae,pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD.Traumatic RRDs were rarely associated with PVD. CONCLUSION： Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.