Intraocular pressure and gonioscopic findings in primary angle-closure disease in India—a big data study

AIM:To describe the gonioscopic profile and intraocular pressure(IOP)in primary angle-closure(PAC)disease in patients presenting to a tertiary eye care network in India.METHODS:A cross-sectional hospital-based study that included 31484 new patients presenting between 2011 and 2021.Patients with a clinical diagnosis of PAC/suspect/glaucoma were included.The data was collected from an electronic medical record system.RESULTS:PAC glaucoma(PACG)(47.55%)was the most common diagnosis followed by PAC(39.49%)and PAC suspect(PACS;12.96%).Female preponderance(54.6%)was noted with higher mean age at presentation among males(P<0.0001).PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade.The probability of angle opening was 95.93%,90.32%and 63.36%in PACS,PAC and PACG eyes respectively post peripheral iridotomy(PI).Plateau iris syndrome(PIS)was noted in 252 eyes and all showed post dilated rise of IOP.A post dilated IOP rise was also noted with 8.86%,33.95%and 57.19%eyes with PACS,PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum.CONCLUSION:The superior quadrant is the narrowest angle and difficult to open with indentation and post PI.The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise.The post dilated IOP rise in angle closure eyes warrants a careful dilatation,especially with PIS.

Analysis of Influence on Aerodynamic Noise of Wind Turbine Blades under Different Pitch Angles

Aiming at the influence of blade pitch Angle on aerodynamic noise of wind turbines, the sound field and flow field distribution at 0˚, 5˚, 10˚ and 15˚ are calculated by numerical simulation. Then, through the distribution of pressure field and velocity field calculated by flow field, the influence of different pitch angles on wind turbine blade aerodynamic noise and the reasons for its influence are analyzed. The results show that when the pitch Angle increases within 0˚ - 10˚, the aerodynamic noise pressure level of the blade decreases. However, the sound pressure level of aerodynamic noise increases in the range of 10˚ - 15˚. The changes of static pressure gradient and pressure pulsation on the blade surface make the aerodynamic noise change, and the changes of the two are positively correlated. At the same time, the fluid velocity and fluid motion state on the blade surface are closely related to the aerodynamic noise of the blade. The greater the fluid velocity, the more complex the fluid motion state and the greater the turbulent kinetic energy of the wind turbine blade, and the aerodynamic noise of the wind turbine blade will also increase.

Exploration on the Optimization Strategy for the Layup of Composite Material Pressure Vessels Based on Advanced Algorithms

This study aims to explore the influence of the laying angle on the pressure shell structure made of composite materials under the condition of a fixed shape. By using a composite material composed of a mixture of T800 carbon fiber and AG80 epoxy resin to design pressure vessels, this material combination can significantly improve the interlaminar shear strength and heat resistance. The article elaborates on the basic concepts and failure criteria of composite materials, such as the maximum stress criterion, the maximum strain criterion, the Tsai-Hill criterion, etc. With the help of the APDL parametric modeling language, the arc-shaped, parabolic, elliptical, and fitting curve-shaped pressure vessel models are accurately constructed, and the material property settings and mesh division are completed. Subsequently, APDL is used for static analysis, and the genetic algorithm toolbox built into Matlab is combined to carry out optimization calculations to determine the optimal laying angle. The research results show that the equivalent stress corresponding to the optimal laying angle of the arc-shaped pressure vessel is 5.3685e+08 Pa, the elliptical one is 5.1969e+08 Pa, the parabolic one is 5.8692e+08 Pa, and the fitting curve-shaped one is 5.36862e+08 Pa. Among them, the stress distribution of the fitting curve-shaped pressure vessel is relatively more uniform, with a deformation of 0.568E−03 m, a minimum equivalent stress value of 0.261E+09 Pa, a maximum equivalent stress value of 0.537E+09 Pa, and a ratio of 0.48, which conforms to the equivalent stress criterion. In addition, the fitting curve of this model can adapt to various models and has higher practical value. However, the stress distribution of the elliptical and parabolic pressure vessels is uneven, and their applicability is poor. In the future, further exploration can be conducted on the application of the fitting curve model in composite materials to optimize the design of pressure vessels. This study provides important theoretical support and practical guidance for the design of composite material pressure vessels.

Epidemiological, Clinical, Therapeutic and Evolutive Profile of Primary Open-Angle Glaucoma in a Cameroonian Population

Background: Sub-Saharan Africa has the highest prevalence of primary open-angle glaucoma (POAG), at 4.2%. The efficacy of medical treatment has been demonstrated and remains one of the treatments of choice for POAG. However, in sub-Saharan Africa, its effectiveness has many challenges, due to multiple factors, including cost and access to care. Thus, the present study aimed to determine the epidemiological, clinical, therapeutic and evolutive profile of primary open-angle glaucoma patients. Methodology: A descriptive cross-sectional study was carried out in two hospitals in western Cameroon. Epidemiological, clinical, therapeutic, and evolutionary data on intraocular pressure at one year after medical treatment were analyzed. SPSS version 23 software was used for statistical analysis, with a significant p-value set at 5%. Results: A total of 201 patients with POAG were included in the study. The population comprised 100 men and 101 women, with a mean age of 54 ± 12 years. At diagnosis, the mean intraocular pressure was 23.9 ± 8.70 mmHg for the right eye and 25.5 ± 9.57 mmHg for the left eye. The mean cup/disc ratio was 0.64 ± 0.2 [0.2-1] and 0.67 ± 0.19 [02-1] in the right and left eyes, respectively. Monotherapy was the most prescribed treatment [59.2%]. After one year of treatment, intraocular pressure was reduced by 15.5% with beta-blockers, 23.66% with prostaglandins, 19.11% with carbonic anhydrase inhibitors, 35, 92% with beta-blockers and carbonic anhydrase inhibitors, 25.92% with beta-blockers and prostaglandins, 48.03% with carbonic anhydrase inhibitors and prostaglandin agonists, and 38.77% with triple therapy. Taking glaucoma severity into account, a significant reduction in intraocular pressure at one year was observed in all participants [p 0.05]. However, the target pressure was obtained in 47%, 20% and 14% of eyes suffering of mild, moderate, and severe grade of POAG respectively. Conclusion: In the present study, there was a significant reduction in intraocular pressure after one year of medical treatment. However, the reduction in intraocular pressure does not allow the target pressure to be reached in severe forms. Thus, alternatives to the medical treatment of POAG should be discussed early in the present context. .

Efficacy of Combined Phacoemulsification and Goniosynechialysis in the Treatment of Patients with Primary Angle Closure Disease and Concomitant Cataract at Preah Ang Duong Hospital in Cambodia

Background: Goniosynechialysis is a surgical procedure that has been shown to slow the progression of glaucoma in oriental eyes with chronic angle closure glaucoma. This procedure was successful in 80% of cases, and the peripheral anterior syenchiae did not exist until one year later. Nonetheless, there is little evidence of its efficacy in our context. Our study aims to investigate the efficacy of goniosynechialysis during phacoemulsification in patients with primary angle closure disease and concomitant cataract. Methods: This was an observational, prospective study. The intra-ocular pressure, need for anti-glaucoma drugs, visual acuity, the extent of synechiae, anterior chamber depth, surgical success rate, and other indicators were monitored for at least three months following surgery. Results: This study included 114 patients (118 eyes), 61 with chronic angle closure glaucoma (51.69%), 33 with primary angle closure (27.97%), and 24 with acute attack angle closure (20.34%), who were surgically treated with phacoemulsification and goniosynechialysis (Phaco-GSL). The mean intra-ocular pressure had significantly decreased three months after surgery (pre- vs post-op: 22.04 ± 10.86 vs 15.41 ± 6.06 mmHg, p-value p-value p-value p-value p-value Conclusion: Regardless of the type of glaucoma, combined phacoemulsification-goniosynechialysis is effective in lowering pressure, restoring vision, reducing the need for anti-glaucoma drugs, and preventing the synechial recurrence. Success was higher in eyes with less extensive synechiae. Phaco-GSL is safe and effective in the treatment of primary angle closure diseases with co-existing cataract.

Impact of Impeller Stagger Angles on Pressure Fluctuation for a Double-Suction Centrifugal Pump

Pressure fluctuation may cause high amplitude of vibration of double-suction centrifugal pumps, but the impact of impeller stagger angles is still not well understood. In this paper, pressure fluctuation experiments are carried out for five impeller configurations with different stagger angles by using the same test rig system. Results show that the stagger angles exert negligible effects on the characteristics of head and efficiency. The distributions of pressure fluctuations are relatively uniform along the suction chamber wall, and the maximum pressure fluctuation amplitude is reached near the suction inlet tongue region. The pressure fluctuation characteristics are affected largely by impeller rotation, whose dominant frequencies include impeller rotation frequency and its harmonic frequencies, and half blade passage frequency. The stagger angle exerts a small effect on the pressure fluctuations in the suction chamber while a great effect on the pressure fluctuation in volute casing, especially on the aspect of decreasing the amplitude on blade passage frequency. Among the tested cases, the distribution of pressure fluctuations in the volute becomes more uniform than the other impeller configurations and the level of pressure fluctuation may be reduced by up to 50% when the impeller stagger angle is close to 24° or 360°.The impeller structure pattern needs to be taken into consideration during the design period, and the halfway staggered impeller is strongly recommended.

Pressure Angle in Parallel Mechanisms: From Planar to Spatial

This paper presents the evolution process of pressure angles from planar parallel mechanisms to spatial parallel mechanisms. Manipulability and condition number, which are frequently used in the optimum design of parallel mechanisms, are introduced from serial robots at first. Then, both theoretical analysis and practical experiences demonstrate that these concepts seem imperfect when they are used in parallel mechanisms. For this reason, this paper introduces the pressure angles in planar 4-bar mechanisms to spatial parallel mechanisms, which include redundant parallel mechanisms. Two kinds of pressure angles extracted from the determinant of direct and indirect Jacobian matrices are investigated. Moreover, two comprehensive and visible global performance indices are defined, showing the advantages in evaluating the workspace, singularity and motion/force transmission capabilities. With a 2-DOF planar and a 3-DOF spatial parallel mechanism as examples, the application of the performance indices is investigated and compared with the condition number at last. The proposed concept can be extended to other spatial parallel mechanisms.

Intraocular pressure-lowering effects of commonly used fixed combination drugs with timolol in the management of primary open angle glaucoma

AIM:To evaluate intraocular pressure(IOP)-lowering effect and ocular tolerability of brimonidine/timolol,dorzolamide/timolol and latanoprost/timolol fixed combination therapies in the management of primary open angle glaucoma.· METHODS:Each drug was administered for two months, after which a circadian tonometric curve was recorded using a Goldmann applanation tonometer.Ocular discomfort(conjunctival hyperemia, burning or stinging, foreign body sensation, itching, ocular pain) of each eye was assessed by the subject on a standardized ocular discomfort scale.RESULTS:Among the three study groups, there were no significant differences in the mean baseline IOP measurements, mean 2ndmo IOP measurements, and mean(%) change of IOPs from baseline. Among the three study groups, there were no significant differences in the mean IOP measurements obtained at circadian tonometric curves at baseline and at two months controls. In sum brimonidine/timolol, dorzolamide/timolol and latanoprost/timolol fixed combination therapies showed similar effects on IOP levels.· CONCLUSION:Brimonidine/timolol, dorzolamide/timolol and latanoprost/timolol fixed combination therapies showed similar lowering efficaties on IOP levels whereas there was no any difference between each other.

Research on reasonable winding angle of ribbons of Flat Steel Ribbon Wound Pressure Vessel

Flat Steel Ribbon Wound Pressure Vessels (FSRWPVs) are used in many important industry areas. There is no such kind of pressure vessel exploding on operation for its reasonable structure design. Many explosion experiments on Flat Steel Ribbon Wound Pressure Vessel showed that their limited load pressure is related to the winding angle of the steel ribbons. FSRWPVs with reasonable winding angle have better security and lower cost. Reasonable angels given at the end of this paper facilitate engineering design.

Pressure Angle Effect of Concave Cylinder Surface on Motion Characteristics of Fiber Placement Machine

There are amounts of issues to be resolved in the process of designing the fiber placement trajectory of the cylindrical component,such as the interference between the machine and the component and the over-travel of the axis of rotation on the fiber placement head.When the pressure on the cylinder surface inclines in a certain direction or at an angle within the normal plane,the motion characteristics of the rotation axis will be different.This paper analyzes the pressure angle effect of the concave cylinder surface on the motion features of a fiber placement machine.The placement area is enlarged by tilting pressure with the same lifting stroke,which is significant in preventing interference and selecting post-processing algorithm.

Contact pressure distribution and support angle optimization of kiln tyre

According to the shearing force character and the deformation coordination condition of shell at the station of supports, the mathematical models to calculate contact angle and contact pressure distribution between tyre and shell were set up, the formulae of bending moment and bending stress of tyre were obtained. Taking the maximum of tyre fatigue life as the optimal objective, the optimization model of tyre support angle was built. The computational results show that when tyre support angle is 30°, tyre life is far less than that when tyre support angle is optimal, which is 35.6°, and it is unsuitable to stipulate tyre support angle to be 30° in traditional design. The larger the load, the less the nominal stress amplitude increment of tyre, the more favorable the tyre fatigue life when tyre support angle is optimal.

Head trauma can cause transient elevation of intraocular pressure in patients with open angle glaucoma

AIM: To describe a newly-recognized entity, illustrated by five cases of glaucoma in whom trauma to the head, but not the eye, resulted in marked, transient elevation of intraocular pressure (IOP). METHODS: Retrospective case series. Chart review. RESULTS: All five cases had a diagnosis of primary open-angle glaucoma prior to the experience of trauma to the head. All cases had an unusual elevation of IOP (around 70 percent) for days to weeks following the trauma, after which the IOP fell to pre-accident levels. No cause other than the trauma could be determined. CONCLUSION: The relationship between head trauma and elevation of IOP appears real.

Effect of tapered angles in an artery on distribution of blood flow pressure with gravity considered

The tapered angles of an artery significantly influence the local hemodynamics. However, as gravity is considered, little is known about the effect of tapered angles on the hemodynamics. In this study, we explored whether the effect of tapered angles on the distribution of blood flow pressure (DBFP) differed with gravity considered or not. Numerical simulations of the DBFP in a single vessel were performed based on such tapered angles as 0°, 0.5° and 1°. In the model used for simulation, gravity was introduced as a body force. We obtained the following simulations: i) The larger the tapered angles were, the better distributed the blood flow pressure;ii) The tapered effect was an important factor leading to nonlinearity in blood flow pressure;iii) Gravity affected DBFP coupling with the tapered angles, yet independently influenced the dimension of the DBFP. At the same time, the effective intensity of gravity decreased with the increase of tapered angles.

Morphological changes in the iridocorneal angle and their relationship with intraocular pressure after infantile cataract surgery

·AIM:To evaluate morphological changes in the iridocorneal angle after pediatric cataract surgery.·METHODS:Children who underwent primary infantile cataract surgery were included and 64 eyes from 41 children,including 18 with unilateral cataracts(18 eyes)and 23 with bilateral cataracts(46 eyes)were examined.All patients underwent two gonioscopic examinations to evaluate the iridocorneal angle,before the primary lens removal and before the secondary intraocular lens implantation.The anatomical changes in the iridocorneal angle and the relationship between intraocular pressure(IOP)and iridocorneal angle changes were also analyzed.·RESULTS:The iridocorneal angle was wide in 64 eyes before and after surgery.The trabecular meshwork pigmentation,number of iris processes in every quadrant of the iridocorneal angle,and the width of the ciliary body band in the superior and inferior quadrants at the second gonioscopic examination were significantly increased compared to those at the first examination(P<0.001,P<0.05,P<0.05.and P<0.05,respectively).IOP gradually increased at 1 mo after operation,and returned to the preoperative level at 3 mo.However,IOP still increased significantly at 6 and 12 mo.·CONCLUSION:The main changes after pediatric cataract surgery include an increase in trabecular meshwork pigmentation and number of iris processes,IOP gradually increase and has positive correlation with trabecular meshwork pigmentation and anterior insertion of iris process.

Research of the Pressure Angle for Whole Cycloidal Gears

The working profile of whole cycloidal gear is made up of epicycloid and hypocycloid entirely, according to the theory of meshing of gears and the properties of the cycloid, deals with the derivation of the pressure angle formula for the whole cycloidal gear in theory, and reveals changes of the pressure angle of whole cycloidal gear through examples, finds the application relationships between the pressure angle and other design parameters of the whole cycloidal gear, proves the possibility that the whole cycloidal gear can be used in internal parallel move gear mechanism, also provides theoretic fundament for designing internal parallel move whole cycloidal gear correctly.

Prediction of atomization characteristics of pressure swirl nozzle with different structures

The structure of the pressure swirl nozzle is an important factor affecting its spray performance.This work aims to study pressure swirl nozzles with different structures by experiment and simulation.In the experiment,10 nozzles with different structures are designed to comprehensively cover various geometric factors.In terms of simulation,steady-state simulation with less computational complexity is used to study the flow inside the nozzle.The results show that the diameter of the inlet and outlet,the direction of the inlet,the diameter of the swirl chamber,and the height of the swirl chamber all affect the atomization performance,and the diameter of the inlet and outlet has a greater impact.It is found that under the same flow rate and pressure,the geometric differences do have a significant impact on the atomization characteristics,such as spray angle and SMD(Sauter mean diameter).Specific nozzle structures can be customized according to the actual needs.Data analysis shows that the spray angle is related to the swirl number,and the SMD is related to turbulent kinetic energy.Through data fitting,the equations for predicting the spray angle and the SMD are obtained.The error range of the fitting equation for the prediction of spray angle and SMD is within 15% and 10% respectively.The prediction is expected to be used in engineering to estimate the spray performance at the beginning of a real project.

Influence of Wellbore Trajectory on Pressure Drop and Fluid Discharge

An experimental analysis has been conducted to study the process of fluid accumulation for different borehole trajectories.More specifically,five heel angles have been experimentally realized to simulate the borehole trajectory of the sloping section of the formation.The fluid-carrying capacity,pressure drop and fluid discharge volatility have been investigated for these conditions and,accordingly,the relationship between heel angle and wellbore pressure drop fluid-carrying capacity has been determined.The results show that while the reasonable roll angle can increase the pressure loss in the wellbore,it is beneficial to drainage.In terms of pressure loss and liquid-carrying capacity,when the heeling angle is 50°,the latter is increased while the former becomes very high,which indicates that when drilling and completing wells on site,a 50°roll angle should be avoided.It is found that the main reason for the increase of the total pressure drop in the wellbore is the increase of the local pressure loss in the inclined section.From the perspective of drainage stability,when there is heeling in the inclined section of the horizontal well,the fluctuation of the wellbore drainage tends to be enhanced.Through the comparison of the Beggs-Brill(B-B)and Mukherjee-Brill liquid holdup methods,it is found that B-B method better predicts liquid holdup.A new method for calculating the pressure drop in the inclined section in the presence of lateral inclination is obtained by taking into account the pressure drop in the curved section.Through comparison with experimental data,it is found that the error is within 20%,and the prediction accuracy is high.

Pressure Changes in Patients with Chronic Renal Failure Undergoing Hemodialysis

Purpose: To determine the effects of hemodialysis on intraocular pressure (IOP) and to evaluate the correlation of IOP changes with anterior chamber angle anatomy. Patients and Methods: The study included 80 eyes of 40 patients with chronic renal failure (CRF) undergoing hemodialysis at the High Technology Medical Center between October 2018 and October 2021. Hemodialysis (HD) was performed 3 times a week and the duration of the procedure was 3 - 5 hours. The enrolled patients were grouped according to the width of the anterior chamber angle. IOP was evaluated at three different times during HD. Intraocular pressure was measured in both eyes in an upright sitting position with iCare tonometer. Results: According to the study results, there was no statistically significant difference in the axial length between the three measurements (p = 0.232). In patients with normal anterior chamber depth, IOP decreased significantly (68.75%) or did not show any changes in their IOP during or after the session. In patients with moderate narrow-angle (22.5%), IOP revealed no statistically significant differences. In patients with narrow-angle (8.75%), there was a marked increase in IOP. Changes in intraocular pressure were correlated with the anatomy of the anterior chamber angle. Loss in body weight as a result of hemodialysis was statistically important (p Conclusion: A significant increase in mean was revealed during and after hemodialysis in patients with extremely narrow-angle in comparison to eyes with wide or moderately anterior chamber angle. Eyes with shallow anterior chambers are at risk of having impaired aqueous humor outflow facilities and, as a result, significantly increase IOP during HD. Because of the high prevalence of narrow angles in the Caucasian population, it is of clinical importance to investigate the IOP changes in patients on HD. The results of our study support the idea that iridocorneal angle anatomy is affecting IOP fluctuation occurring in patients with ESRD undergoing HD.

Two-year outcomes of ab interno trabeculectomy with the Trabectome for Chinese primary open angle glaucoma： a retrospective multicenter study

AIM： To evaluate the 2-year efficacy and safety of ab interno trabeculectomy with the Trabectome in Chinese primary open angle glaucoma （POAG） patients. METHODS： This was a multicenter, retrospective, observational study and included POAG patients with or without visually-significant cataracts. The Chinese patients were enrolled from three glaucoma centers and a group of comparable Japanese POAG patients was analyzed from our international Trabectome database. The patients received Trabectome or a combined surgery with phacoemulsification and intraocular lens implantation. The primary outcome was intraocular pressure （IOP） reduction. Secondary outcomes included reduction of glaucoma medications, surgical complications, and success at 2y. Success was defined as： 1） IOP≤21 mm Hg and at least 20% IOP reduction from baseline after 3mo at any two consecutive visits; 2） no additional glaucoma surgery required. RESULTS： A total of 42 Chinese POAG patients from three glaucoma centers were enrolled. Twelve patients underwent Trabectome surgery combined with phacoemulsification and intraocular lens implantation while the remainder underwent Trabectome surgery alone. Thirteen patients had a history of failed glaucoma surgery and were considered as complicated cases. In China data, the mean preoperative IOP was 21.4±1.23 mm Hg. The Trabectome lowered IOP to 17.9±1.8 mm Hg at 2y （P=0.05）. The number of glaucoma medications also decreased significantly from a baseline of 2.0±0.9 to 1.1±0.8 at 2y post-surgery （P=0.04）. The overall 2-year success rate was 78%, with patients undergoing combined surgery having a higher success rate compared with those undergoing Trabectome surgery alone （100% vs 76%）. In Japan data, the mean preoperative IOP was 20.8±7.7 mm Hg. The Trabectome lowered IOP to 12.20±2.0 mm Hg at 2y. The number of glaucoma medications also decreased significantly from a baseline of 2.1±0.9 to 3.4±0.6 at 2y post-surgery. In all patients, no major complications were seen. CONCLUSION： Surgery with the Trabectome appears to be an efficient and safe procedure in Chinese POAG patients in the long-term.

Systematic review and Meta-analysis of treating open angle glaucoma with gonioscopy-assisted transluminal trabeculotomy

●AIM:To systematically review and Meta-analyze studies of managing open angle glaucoma(OAG)with gonioscopyassisted transluminal trabeculotomy(GATT)and to evaluate its effectiveness and safety.●METHODS:Eligible studies were retrieved and screened from five main electronic databases.Mean difference(MD)was hired to show the pooled effectiveness of intraocular pressure(IOP)and medication decrease achieved by GATT.In addition,combined surgical success and reoperation rates were calculated,and complications were also summarized.●RESULTS:Ten studies were included for systematic review,but one study was not pooled for Meta-analysis due to the repeated data.The combined IOP decrease after GATT was 9.81 mm Hg(95%CI:7.98-11.63 mm Hg)which showed significant reduction from the baselines(Z=10.52,P<0.0001).Similarly,the number of medications after GATT also decreased distinctly compared with that of medication before the surgery(Z=9.09,P<0.0001),and the pooled medication decrease was 1.68(95%CI:1.31-2.04).In addition,the combined surgical success rate was 85%,while the pooled reoperation rate was 20%.Sightthreatening complications occurred scarcely,whereas the pooled occurrence rate of hyphemia was as high as 36.0%.●CONCLUSION:GATT could effectively lower IOP and decrease medications for patients with OAG.Moreover,the procedure appears to be a safe and promising treatment for OAG due to its minimally-invasive and conjunctiva-sparing nature.