Changes in Schlemm’s canal,trabecular meshwork,and relevant parameters in the early stage after SMILE of myopia patients

AIM:To observe the changes in Schlemm’s canal(SC),trabecular meshwork(TM),and anterior chamber relevant parameters after small incision lenticule extraction(SMILE) of myopia patients.METHODS:A total of 58 eyes from 30 patients who underwent SMILE were divided into a low and moderate myopia group(group A,32 eyes) and a high myopia group(group B,26 eyes).The diameter and area of the SC,the width and thickness of TM obtained by CIRRUS HD-OCT5000,and the related anterior chamber parameters obtained by Pentacam anterior segment analysis system,accommodation amplitude(AMP) were observed pre-and postoperatively.The preoperative intraocular pressure(IOP) and postoperative correction of intraocular pressure(IOPcc) were measured.RESULTS:The diameter and area of the SC in the two groups were significantly increased postoperatively(all P<0.01).The TM width of the patients in the two groups were increased at 1mo after surgery(both P<0.01),but the TM thickness did not change(P>0.05).The corneal curvature,central anterior chamber depth,and anterior chamber volume decreased after SMILE surgery(all P<0.01).There was a weak negative correlation between the SC area change and AMP change in group A(r=-0.362,P<0.01).The postoperative IOP decreased after correction by Shah formula(P<0.05).CONCLUSION:SC and TM in myopia patients change in the early postoperative stage of SMILE and the IOP is decline.

Schlemm's管小梁切除术临床疗效观察(附13眼报告)

目的探讨Schlemm's管小梁切除术对青光眼的临床疗效。方法选择13例双眼慢性青光眼,一侧眼为绝对期,另一侧眼为青光眼中晚期患者,共26只眼。13只绝对期青光眼施行Schlemm's管小梁切除术,另13只中晚期慢性青光眼行常规小梁切除术。结果全部病例经1～3年随访观察,Schlemm's管小梁切除术眼,眼压控制均优于常规小梁切除术眼。除3只眼术后前房有少许出血外均未发生任何严重的并发症,眼压<18mmHg9只眼;眼压<25mmHg4只眼。结论Schlemm's管小梁切除术可为抗青光眼手术提供一项手术方式,供临床选择。

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.

Abnormal Systemic and Ocular Responses to the Valsalva Manoeuvre in Primary Open-Angle Glaucoma:A Case for Autonomic Failure?

Objective This study aimed to examine the association of primary open-angle glaucoma(POAG)with autonomic dysfunction by assessing the differences in systemic and ocular responses to an autonomic provocation test,the Valsalva manoeuvre(VM),between POAG patients and normal subjects.Methods Forty POAG and forty control subjects were subjected to the VM.Systemic and ocular parameters were measured at baseline,phase 2,and phase 4 of the VM(VM2 and VM4),where VM2 and VM4 are sympathetic and parasympathetic nervous activation states,respectively.Heart rate variability was used to assess the autonomic nervous activity,among which the high-frequency component(HF)and the low-frequency(LF)/HF ratio were used as indices of parasympathetic and sympathetic activation,respectively.Results POAG patients demonstrated higher sympathetic activation(LF/HF ratio median:2.17 vs.1.53,P=0.000)than controls at baseline and exhibited attenuated sympathetic and parasympathetic responses(a smaller change in LF/HF and HF values)during the VM than controls.During VM,the intraocular pressure(IOP),mean blood pressure(MAP),mean ocular perfusion pressure(MOPP),and the Schlemm’s canal area(SCAR)increased from baseline to VM2 and then decreased from VM2 to VM4 in both the POAG and control groups(all P<0.05).However,when we compared the changes above,the fluctuations in IOP,MAP,and MOPP were more pronounced in POAG than in controls(all P<0.05),while the changes in amplitudes of SCAR were smaller in POAG(P<0.05).Furthermore,from VM2 to VM4,the choroid thickness(ChT)in the POAG group was significantly decreased,while it was unchanged in normal subjects(P=0.258).A regression analysis showed a significant correlation of the baseline LF/HF with IOP change values(ΔIOP)from baseline to VM2 in POAG(R^(2)=0.147,P=0.014).Conclusion Patients with POAG showed more pronounced fluctuations in IOP,MAP,MOPP and ChT during the VM than controls.These reactions could be associated with autonomic dysfunction in POAG.

Modified viscocanalostomy in the Chinese population with open angle glaucoma: a 10-year follow-up results

AIM: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma(OAG).METHODS: This retrospective study included a total of 100 eyes from 100 Chinese patients with medically uncontrolled OAG. All the patients underwent modified viscocanalostomy with injection of viscoelastic material in the surgically created ostia of Schlemm's canal(SC). The modifications included peeling of the inner wall of SC and the juxtacanalicular meshwork, use of mitomycin C, and loosely suturing the superficial scleral flap. Intraocular pressure(IOP), visual acuity, number of medications, laser goniopuncture data and complications were recorded. The definition of complete(qualified) success was an IOP equal to or lower than 21, 18, 16 mm Hg without(with or without) anti-glaucoma medications. RESULTS: The mean IOP was 33.5±9.9 mm Hg before surgery, 15.2±3.6 mm Hg(mean IOP reduction of 51%) at 5 y after surgery, and 15.6±2.8 mm Hg(mean IOP reduction of 49.9%) at 10 y after surgery(P<0.001). The number of anti-glaucoma medications dropped from 2.39±0.5 preoperatively to 0.47±0.8 at 5 y and 0.67±0.8 at 10 y postoperatively(P<0.001). The follow-up period was 104.5±37.0 mo. The qualified success rate for an IOP of 21, 18 or 16 mm Hg or less was 84% [95% confidence interval(CI): 0.80-0.88], 73%(95%CI: 0.68-0.78), and 59%(95%CI: 0.52-0.66) after 5 y, and 80%(95%CI: 0.76-0.84), 69%(95%CI: 0.64-0.74), 51%(95%CI: 0.44-0.58) after 10 y, respectively. There was a relationship between age, preoperative IOP and success rate(P<0.01, P<0.05). A total of 31 eyes(31.3%)in 31 patients underwent laser goniopuncture, decreasing the IOP from 22.9±4.3 mm Hg to 16.3±2.5 mm Hg(P<0.01). Neither blebitis nor endophthalmitis occurred.CONCLUSION: Modified viscocanalostomy could be performed to lower IOP, decrease multiple anti-glaucoma drops use as well. It's a safe procedure with less complications over 10 y in Chinese individuals with OAG.

360°Schlemm's管切开术与小梁切开术对青光眼患者角膜生物力学和视力的影响比较

目的比较房角镜辅助的360°Schlemm’s管切开术(gonioscopy assisted transluminal trabeculotomy,GATT)与外路微导管引导的小梁切开术(microcatheter assisted trabeculotomy,MAT)对原发性开角型青光眼(POAG)患者角膜生物力学和视力的影响。方法回顾性分析2020年8月至2022年8月郑州大学第一附属医院收治的POAG患者90例(90眼)的临床资料,其中行GATT治疗的患者56例(56眼),行MAT治疗的患者34例(34眼),所有手术由同一术者完成。根据性别、年龄等因素进行倾向性得分匹配,GATT组和MAT组各30例(30眼)入组,比较两组基线资料、手术成功率和术前、术后1周、1个月、3个月的眼压、抗青光眼药物使用数量、角膜生物力学参数[第一压平时间(A1T)、第二压平时间(A2T)、最大压陷时间(HCT)、最大形变幅度(DA)、最大压陷屈膝峰间距(PD)]、视力和并发症发生情况。结果术后1周、1个月及3个月两组眼压均较术前降低,抗青光眼药物使用数量、A1T均较术前下降,A2T、DA、PD、视力较术前升高,差异均有统计学意义(均P<0.05)。术后1周、1个月及3个月,GATT组和MAT组眼压、抗青光眼药物使用数量、A1T、A2T、DA、PD、视力组间比较,差异均无统计学意义(t=0.384、0.318、1.187;0.289、1.933、0.687;0.610、0.197、0.279;0.062、0.856、0.046;0.369、0.899、0.125;0.310、0.619、0.643;0.264、0.089、0.273;0.701、1.879、1.519;P=0.703、0.751、0.066;0.774、0.058、0.495;0.544、0.844、0.782;0.951、0.396、0.963;0.714、0.373、0.901;0.758、0.538、0.523;0.793、0.929、0.786;0.486、0.065、0.134)。GATT组和MAT组完全成功率和条件成功率组间比较,差异均无统计学意义(χ^(2)=0.739、1.456,P=0.390、0.228)。GATT组和MAT组术后均有出血,两组术后睫状体脱离、浅前房发生率组间比较,差异均无统计学意义(χ^(2)=0.317、1.107,P=0.573、0.313)。结论GATT和MAT治疗POAG的疗效相当,可作为POAG患者的有效手术选择。

不同算法在UBM小梁网区域分割中的应用

目的探讨不同算法在超声生物显微镜(ultrasonic biological microscope,UBM)图像中小梁网区域自动或半自动分割中的应用,实现小梁网-舒林氏管(trabecular meshwork-schlemm's canal,TM-SC)边界的自动化识别,为后续的TM-SC定量、定性分析提供基础。方法采用原发性开角型青光眼(primary open angle glaucoma,POAG)患者80 MHz UBM房角图像,应用Ostu、K-means和Level set 3种分割算法和开源医学图像处理软件ImageJ对小梁网区域图像进行分割,提取感兴趣的TM-SC区域。结果Ostu、K-means算法不能准确识别TM-SC边界,Level set算法能够准确分割出TM-SC边界,ImageJ软件可手动分割小梁网区域,其效果主要取决于操作者的经验,但速度慢、重复性差。结论Level set算法可准确分割出UBM图像中TM-SC边界,TM-SC后续的几何度量对阐明青光眼发病机制具有重要的临床价值和指导意义。

Hydrus microstent implantation for surgical management of glaucoma: a review of design, efficacy and safety

With the advent of microinvasive glaucoma surgery(MIGS),the spectrum of modalities available to manage patients with this chronic and heterogeneous condition has broadened.Despite its novelty however,there has been a rapid evolution in the development of a multitude of devices,each targeting a structure along the aqueous drainage pathway.A growing body of evidence has demonstrated IOP and medication burden reduction,and a more favorable safety profile with MIGS procedures in contrast to traditional incisional surgeries.Among the array of MIGS,the Hydrus®Microstent(Ivantis,Inc.,Irvine,CA)is a recent FDA approved device,designed to bypass the trabecular meshwork and provide a scaffold for Schlemm’s canal.The objective of this article is to review the Hydrus from conception to clinical use,and present data on its efficacy and safety to date.The available literature has shown promise,however inherent to all novel devices,only longterm monitoring will ensure sustained IOP control and an acceptable safety profile.Surgical advancements in glaucoma have revolutionized the field,and continued research and development will establish these approaches in clinical treatment algorithms.

Ab externo canaloplasty results and efficacy: a retrospective cohort study with a 12-month follow-up

Background:The aim of this study is to review the outcomes of canaloplasty versus canaloplasty combined with phacoemulsification in a retrospective cohort study and to evaluate the efficacy of these methods in terms of intraocular pressure(IOP)lowering effect,postoperative complications and additional glaucoma surgery or reintroduction of medical therapy over a 12-month follow-up.Methods:In a retrospective cohort study,602 eyes with primary open angle glaucoma(POAG)were treated with canaloplasty or canaloplasty combined with phacoemulsification.The results were evaluated separately in two main groups;group A canaloplasty(262 eyes)and group B canaloplasty combined with phaco(322 eyes).Each group was then subdivided into three additional groups according to the severity of glaucoma.The criteria for successful treatment were evaluated between three IOP ranges;IOP≤16 mmHg,18 mmHg and 21 mmHg.Complete success was considered the percentage of eyes reaching target IOP with no medication and partial success with medication.Groups A and B subgroups were compared using the Kaplan Meier test.Mean IOP,reduction of antiglaucoma agents and additional IOP lowering methods were also evaluated.The follow-up time was 12 months.Statistical significance was set at p<0.05.Results:An incomplete intraoperative cannulation of Schlemm’s canal resulting in conversion to other glaucoma surgery occurred in 18 eyes(2.99%).In both of the main groups,postoperative hyphema,descemet membrane detachment and transient IOP rise were the most common postoperative complications.The mean IOP in group A and subgroups at 12 months was 13.26±4.5 mmHg,15.19±3.97 mmHg and 18.09±3.75 mmHg.Respectively in group B mean IOP was 14.51±4.69 mmHg,14.40±4.11 mmHg and 14.25±2.76 mmHg.Complete success was achieved in group A in 69.19,74.51 and 74.31%of eyes.In group B complete success was achieved in 81.60,77.33 and 83.33%of eyes respectively.Kaplan Meier between groups A and B was statistically significant for IOP≤16 mmHg and IOP≤21 mmHg(p=0.0041 and p=0.0312),but not for IOP≤18 mmHg(p=0.6935).Partial success for IOP≤16 mmHg was 95.23 and 92.26%,for IOP≤18 mmHg was 91.66 and 90.47%and for IOP≤21 mmHg,90.00 and 93.10%,in groups A and B respectively.Twenty-three eyes received additional surgery(3.93%),10 trabeculectomies and 2 cyclophotocoagulation in group A,and 9 trabeculectomies and 2 cyclophotocoagulation in group B.Conclusion:Canaloplasty and canaloplasty combined with phacoemulsification significantly lower the IOP and have a lower postoperative complication rate.Additional glaucoma surgery or medication following both procedures is necessary if target IOP is unsatisfactory.In this study,canaloplasty combined with phacoemulsification demonstrated superior success rate compared to canaloplasty alone.