Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia

●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical trial was conducted.Totally 98 eyes(74 patients)who underwent femtosecond laser-assisted cataract surgery(FLACS)with trifocal IOLs were enrolled in the study and followed up for 2y after surgery:46 eyes(33 patients)with capsular tension ring implantation in the long axial lengths(AL)group(26<AL<29 mm)and 52 eyes(41 patients)in the normal AL group(22<AL<24.5 mm).Postoperative outcomes about effectivity and safety,including the subjective and objective visual quality,and postoperative complications were assessed.●RESULTS:Uncorrected distance visual acuity at 5 m and uncorrected intermediate visual acuity at 60 and 80 cm in the long AL group were significantly worse than those in the normal AL group at 3mo postoperatively(P<0.05).The differences in reading speed,spectacle independence and potential visual complaints between the two groups were not statistically significant(P>0.05).The dysfunctional lens index and total modulation transfer function(MTF)average height were similar between the two groups.The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group(P<0.05).The total satisfaction score in the long AL group(91.32±2.76)was slightly higher than that in the normal AL group(90.36±3.47),but there was no difference(P=0.136).A statistically negative correlation was found between corrected distance visual acuity(CDVA)and dysfunctional lens index(r=-0.382,P=0.009),and between CDVA and the total MTF average height(r=-0.374,P=0.01).But there was no significant correlation between CDVA and total satisfaction score(r=0.059,P=0.696).Postoperative complications mainly presented as posterior capsular opacity(PCO),retinal detachment and cystoid macular edema.There was no difference in the incidence of fundus disease(6.5%vs 3.8%,P=0.663)or PCO(17.4%vs 7.7%,P=0.217)between the two groups at two years.●CONCLUSION:The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS.This approach not only ensures excellent subjective feelings and objective visual quality,but also does not increase the incidence of postoperative complications.

Stability of neodymium:YAG laser posterior capsulotomy in eyes with capsular tension rings

·AIM: To evaluate the stability of neodymium(Nd):YAG laser posterior capsulotomy in eyes with capsular tension rings(CTRs).·METHODS: A total of 60 eyes that underwent cataract surgery and laser posterior capsulotomy postoperatively were included in this retrospective cohort study. To evaluate the safety and stability of capsulotomy, changes in the size of posterior capsulotomy and anterior chamber depth(ACD) in three groups: the group without CTR, the group with 12 mm CTRs, and the group with 13 mm CTRs, at 1wk, 3, 12, and 15mo after capsulotomy, were compared. ·RESULTS: In the group without CTR and the group with 12 mm CTR, there was no significant change in ACD at every post-laser follow-up. In the group with 13 mm CTR, the ACD change was significant until 3mo after capsulotomy. In all groups, there was a significant increase in the area of capsulotomy between 1wk and 3mo post-laser. Between 3 and 12mo post-laser, only the group with 13 mm CTR showed a significant increase in the area of capsulotomy(P<0.01). ·CONCLUSION: Laser posterior capsulotomy is safe in all three groups. The capsulotomy and ACD become stabilized and have not shown significant changes since 1y postlaser, even with larger CTRs. The maintenance of centrifugal capsular tension can last longer with larger CTRs, and the stability of the capsulotomy site can be reached about 12mo after capsulotomy in pseudophakic eyes with larger CTRs.

Technique of using Cionni-modified capsular tension ring in the management of severely traumatic lens subluxation

AIM:To investigate the effect of Cionni-modified capsular tension ring(CTR)implantation in patients with severely traumatic subluxated cataracts.METHODS:All patients who totally had traumatic cataracts and lost zonule support and underwent cataract surgery were retrospectively analyzed.Corrected distance visual acuity(CDVA),extent of zonulysis,intraocular lens(IOL)position,intraoperative presentation,and complications were assessed.The primary outcomes included IOL centration stability and other postoperative complications.RESULTS:Twenty patients(20 eyes)were included in this study.The mean age in this study was 58.0±11.3y,and the average follow-up time was 17.3±12.8mo.Capsule bags were saved by Cionni-modified CTR.Nine eyes(45%)underwent simultaneously anterior vitrectomy due to the presence of vitreous in the anterior chamber.The preoperative mean CDVA was 0.83±0.24 log MAR,and the postoperative average CDVA was 0.23±0.30 log MAR(P<0.05).The horizontal and vertical IOL decentration after surgery was 0.27±0.12 mm and 0.41±0.19 mm,respectively;the vertical and horizontal IOL tilt after surgery was 5.5°±2.5°and 6.1°±2.2°,respectively.None of the eyes had obvious IOL decentration during the follow-up time.Eight eyes(40%)had posterior capsule opacification(PCO)that was severe enough to cause poor vision.Neodymium:YAG laser capsulotomy were performed on these eyes when the CTR was stabilized.CONCLUSION:With the help of Cionni-modified CTR,capsular bag preservation and better IOL concentration can be achieved without major complications in patients with severely traumatic subluxated cataracts.

Comparative evaluation of rotational stability of toric IOLs with four-eyelet vs two-eyelet capsular tension rings in eyes with high myopia

AIM:To compare the rotational stability of Toric intraocular lens(IOLs)implantation combined with foureyelet or two-eyelet capsular tension rings(CTRs)in eyes with high myopia and cataract.METHODS:This prospective randomized controlled interventional study in cluded 33 eyes which had preoperative corneal astigmatism≥1.5 D and ocular axial length≥25.5 mm.These eyes were randomly divided into two groups to undergo phacoemulsification and toric IOL implantation with either four-eyelet CTR implantation(group A,n=16)or two-eyelet CTR implantation(group B,n=17).Uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA),phoropter examination results,and toric IOL rotation degrees were tested 6 mo after the surgery.RESULTS:In both groups,the toric IOL was in the capsular sac 6 mo after surgery.The difference between the two groups in terms of visual outcome was not found to be statistically significant(P>0.05)at a follow-up of 6 mo.The mean residual astigmatism values were 0.56±0.22 D and 0.92±0.24 D in A and B groups,respectively(P<0.001).The mean rotation degree of IOL was 1.00°±0.73°in group A and 3.53°±1.46°in group B(P<0.001).CONCLUSION:In cataract patients with high myopia and astigmatism,four-eyelet CTR can effectively increase the rotation stability of toric IOLs,achieving the desired goal of correcting corneal astigmatism.

Effect of capsular tension ring implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation syndrome

AIM: To investigate the effect of capsular tension ring(CTR) implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation(PEX) syndrome.METHODS: This double-blind randomized clinical trial was conducted on 60 patients with PEX syndrome referring to Imam Khomeini Hospital affiliated to Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, for undergoing cataract surgery. The study population was divided into two groups, namely CTR group(n=30) and non-CTR group(control group;n=30). The refractive error and anterior chamber depth(ACD) were measured 1 wk, 1 mo, and 3 mo after phacoemulsification(PE) surgery.RESULTS: The results indicated no statistically significant difference between the two groups in terms of predicted refractive error(obtained by subtracting preoperative predicted refractive error from actual postoperative refractive error) 1 wk(P=0.47), 1 mo(P=0.30), and 3 mo(P=0.06) after the PE surgery. Regarding the CTR group, the changes of ACD was statistically significant 1 and 3 mo after the PE surgery, compared to those obtained 1 wk post-surgery(P=0.005).CONCLUSION: The CTR implantation in PEX cataractous patients without zonulysis has no statistically significant effect on the predicted refraction and ACD changes after PE. The predicted refraction error has a hyperopic shift in both groups. The results reveal the unnecessary of calculating modified IOL in CTR implantation.

Effective treatment for secondary angle-closure glaucoma caused by traumatic lens subluxation:phacoemulsification with capsular-tension-ring implantation combined with ophthalmic endoscope-controlled goniosynechialysis

AIM:To investigate the safety and efficacy of phacoemulsification with capsular-tension-ring implantation and posterior chamber intraocular lens implantation combined with ophthalmic endoscope-controlled goniosynechialysis(Phaco-CTR-IOL-OE-GSL)for treating secondary angle-closure glaucoma induced by traumatic lens subluxation.METHODS:A retrospective and descriptive study was performed on patients with lens subluxation,angle closure,goniosynechia,and evaluated intraocular pressure(IOP)that cannot be controlled with medication,who underwent Phaco-CTR-IOL-OE-GSL.The postoperative best-corrected visual acuity(BCVA),IOP,range of goniosynechia and complications were retrospectively observed.RESULTS:Nine patients with secondary angle-closure glaucoma induced by traumatic lens subluxation were included.The follow-up period was 51.1±8.6 mo.The preoperative range of zonule rupture was 158.2°±33.0°,and the range of goniosynechia was 220.0°±92.5°.The baseline BCVA was 0.9±1.0 logMAR,IOP was 30.7±17.3 mm Hg and number of anti-glaucoma medication was 3.2±1.1.Mild intraoperative hyphaemia with 8 eyes(88.8%)in the anterior chamber,and was absorbed two days postoperatively.One eye(11.1%)had postoperative ciliary body detachment and was recovered after five days of topical drug treatment.BCVA was 0.2±0.2 logMAR at 3 mo postoperatively.The average IOP at the last follow-up was 16.7±2.0 mm Hg,and no anti-glaucoma medications were used.The average range of recurrent goniosynechia was 54.9°±33°at the final postoperative gonioscopic examination.CONCLUSION:Phaco-CTR-IOL-OE-GSL is safe and effective in the treatment of secondary angle-closure glaucoma induced by traumatic lens subluxation.The use of an endoscope provides a more direct and clear examination for GSL,and 360°dissection is easily achieved.

Placement of dual capsular tension rings for the combined management of traumatic cyclodialysis cleft and zonular dialysis

Background:To evaluate the efficacy and safety of placing dual capsular tension rings for the combined management of traumatic cyclodialysis cleft and zonular dialysis.Methods:A modified capsular tension ring was inserted into the ciliary sulcus and a capsular tension ring or modified capsular tension ring was inserted into the capsular bag in 20 eyes in 20 consecutive patients showing signs of ocular hypotony and ectopia lentis.Outcome measures included intraocular pressure,best-corrected visual acuity,and postoperative complications.Results:Dual capsular tension ring placement was performed in 20 patients with a mean age of 48.7 years.The cyclodialysis cleft extended over 2.9 clock hours(range 0.5-6.5).The modified capsular tension ring was successfully inserted into the ciliary sulcus and a capsular tension ring or modified capsular tension ring in the capsular bag in all eyes.At the last follow-up,the cyclodialysis cleft was closed in 16/20(80.0%)eyes.The intraocular lens was stable in all patients postoperatively.Best-corrected visual acuity,in terms of the logarithm of the minimal angle of resolution,improved from 1.3±0.8 before surgery to 0.4±0.3 after surgery(P<0.001).Intraocular pressure increased significantly from 10.6±3.2 mmHg before surgery to 13.0±4.8 mmHg after surgery(P=0.040).Postoperative complications included a painful reversible intraocular pressure spike in four patients(20.0%).Logistic regression revealed no significant factors associated with successful cleft closure and a stable final intraocular pressure of≥10 mmHg.Conclusions:The placement of two capsular tension rings into the ciliary sulcus and the capsular bag is a safe,successful procedure combined for repairing a traumatic cyclodialysis cleft and managing zonular dialysis.

Placement of dual capsular tension rings for the combined management of traumatic cyclodialysis cleft and zonular dialysis

Background:To evaluate the efficacy and safety of placing dual capsular tension rings for the combined management of traumatic cyclodialysis cleft and zonular dialysis.Methods:A modified capsular tension ring was inserted into the ciliary sulcus and a capsular tension ring or modified capsular tension ring was inserted into the capsular bag in 20 eyes in 20 consecutive patients showing signs of ocular hypotony and ectopia lentis.Outcome measures included intraocular pressure,best-corrected visual acuity,and postoperative complications.Results:Dual capsular tension ring placement was performed in 20 patients with a mean age of 48.7 years.The cyclodialysis cleft extended over 2.9 clock hours(range 0.5-6.5).The modified capsular tension ring was successfully inserted into the ciliary sulcus and a capsular tension ring or modified capsular tension ring in the capsular bag in all eyes.At the last follow-up,the cyclodialysis cleft was closed in 16/20(80.0%)eyes.The intraocular lens was stable in all patients postoperatively.Best-corrected visual acuity,in terms of the logarithm of the minimal angle of resolution,improved from 1.3±0.8 before surgery to 0.4±0.3 after surgery(P<0.001).Intraocular pressure increased significantly from 10.6±3.2 mmHg before surgery to 13.0±4.8 mmHg after surgery(P=0.040).Postoperative complications included a painful reversible intraocular pressure spike in four patients(20.0%).Logistic regression revealed no significant factors associated with successful cleft closure and a stable final intraocular pressure of≥10 mmHg.Conclusions:The placement of two capsular tension rings into the ciliary sulcus and the capsular bag is a safe,successful procedure combined for repairing a traumatic cyclodialysis cleft and managing zonular dialysis.

“NIR-triggered ROS storage”photodynamic intraocular implant for high-efficient and safe posterior capsular opacification prevention

Posterior capsular opacification(PCO)is the leading cause of vision loss after cataract,mainly caused by the adhesion,proliferation and trans-differentiation of post-operative residual lens epithelial cells(LECs).Effective PCO prevention remains a huge challenge to ophthalmologists and researches for decades.Herein,we developed a“NIR-triggered ROS storage”intraocular implant(CTR-Py-Pp IX)based on capsular tension ring(CTR),which is concurrently linked with photosensitizer protophorphyrin IX(Pp IX)and energy storage2-pyridone derivative(Py),to guarantee instantaneous and sustainable ROS generation for LECs killing,aiming to achieve more efficient and safer photodynamic therapy(PDT)to effectively prevent PCO.The silylated Pp IX-Si and Py-Si were covalently conjugated to the plasma activated CTR surface to obtain CTR-Py-Pp IX.Results demonstrated that CTR-Py-Pp IX had dual functions of PDT and battery,in which Pp IX could generate ROS extracellularly under irradiation,with one part directly inhibiting LECs by lipid peroxidation(LPO)induction of cell membranes.Meanwhile,the excess ROS stored in Py could be continuously released to amplify LPO levels after the irradiation was removed.Ultimately,the proliferation of LECs in capsular bag was completely inhibited under mild irradiation conditions,achieving a sustainable and controlled PDT effect for effective PCO prevention with good biocompatibility.This NIR-triggered ROS storage intraocular implant would provide a more efficient and safer approach for long-term PCO prevention.

Computation and Measurement of Winding Tension in Ring Spinning

By studying the variations of balloon height and of wind-ing radius in any one winding layer of ring spinning, the formula for determining the winding tension in any layer is derived, and then the overall tension variation throughout all winding layers can be computed. A meth-od of measuring the winding tension is also introduced here, with the measured results agreeing with the com-puted ones, and so the reliable relationship between winding tension, speed and ring traveller weight can be thus obtained. The highest allowable spindle speed is also discussed.

囊袋张力环联合Toric人工晶状体植入治疗高度近视合并角膜散光的白内障

目的研究伴有角膜散光的高度近视白内障患者进行超声乳化+环曲面人工晶状体(Toric intraocular lens,Toric IOL)及囊袋张力环(capsular tension ring,CTR)植入术的临床效果及稳定性。方法通过回顾性研究,分析在武汉市第一医院行白内障超声乳化吸除术的高度近视伴有角膜散光的患眼54例(76眼),其中31例(38眼)联合植入Toric IOL及CTR(联合组),23例(38眼)单纯植入Toric IOL(对照组)。术后随访6个月,比较两组患者术前及术后视力、角膜内皮细胞密度、人工晶状体旋转度、残余散光度,以及并发症发生情况。结果术后6月,两组患者裸眼远视力(uncorrected distance visual acuity,UCVA)、最佳矫正视力(best corrected visual acuity,BCVA)均显著高于术前,联合组术后UCVA(LogMAR)优于对照组,差异有统计学意义[(0.34±0.15)vs.(0.46±0.25),P<0.05]。术后1周、1月、3月及6月,联合组散光分别为(0.38±0.31)、(0.45±0.25)、(0.47±0.23)、(0.56±0.26),均明显低于对照组各时间点(均P<0.01)。术后6月联合组IOL平均旋转(2.63±0.94)°,显著低于对照组的(4.00±1.43)°(P<0.01)。两组间各时间点角膜内皮细胞密度比较,差异无统计学意义(均P>0.05)。联合组术后并发症总发生率低于对照组(P<0.05)。结论对于高度近视伴角膜散光的白内障患者,术中植入Toric IOL的同时联合应用CTR,安全性好,能够改善Toric IOL旋转稳定性,提高视觉质量,并且减少并发症。

囊袋张力环对高度近视患者Barrett universalⅡIOL计算公式准确性的影响

目的:评估囊袋张力环(CTR)对Barrett universalⅡ人工晶状体(IOL)计算公式在高度近视合并白内障患者术后屈光状态的稳定性与准确性的影响。方法:本研究为前瞻性研究。选取2022-01/06于我院就诊的高度近视白内障患者40例80眼。采用随机数字表法分为CTR组和空白组,每组40眼,所有患者均用IOL Master测量,并按照Barrett universalⅡ公式计算实际植入IOL屈光度及预测术后屈光度。记录患者术后6 mo的裸眼视力(UCVA)、最佳矫正视力(BCVA),比较术后6 mo两组平均绝对屈光误差(MAE),评估术后屈光状态的稳定性及预测术后屈光度与CTR的关系。结果:术后6 mo两组患者UCVA、BCVA均较术前改善(P>0.05),不同时间点两组UCVA、BCVA比较无差异(均P>0.05);80眼按照Barrett universalⅡ公式植入IOL后,CTR组预计术后屈光度为-2.01±0.71 D,术后实际屈光度为-1.64±0.88 D,MAE为0.37±0.98 D;空白组预计术后屈光度为-2.12±0.64 D,术后实际屈光度为-1.54±0.88 D,MAE为0.58±0.31 D,组间比较有差异(P<0.05)。根据眼轴长度进行分组,对于任意眼轴长度CTR的植入均能有效地减少屈光误差(P>0.05)。随着眼轴的增长,MAE的值越大,眼轴≥30 mm的患者术后MAE值比较两组间有差异(P<0.05)。CTR组、空白组中出现远视漂移的比例分别是18%(7/40)、30%(12/40),组间比较有差异(P<0.05)。结论:对高度近视合并白内障患者,Barrett universalⅡ公式在预测术后屈光度方面具有较高的准确性,术中植入CTR既能够保持囊袋的形态,有效防止术中晶状体悬韧带断裂,使IOL居中性更佳,又能有利于白内障患者术后屈光度的早期稳定,并提供更加稳定的屈光结果,减少屈光漂移。对于术中考虑植入CTR的近视患者,建议术前增加-0.50 D的预留屈光度,以达到理想屈光状态。

巩膜固定囊袋张力环联合超声乳化人工晶状体植入术治疗外伤性晶状体半脱位

目的:探讨巩膜固定囊袋张力环(SFCTR)植入联合晶状体超声乳化吸除加人工晶状体(IOL)植入术治疗外伤性晶状体半脱位的临床疗效。方法:连续选取2018-12/2023-02行SFCTR植入联合晶状体超声乳化吸除加IOL植入术治疗的外伤性晶状体半脱位患者14例14眼。术后随访行视力、眼压、眼前段照相、超声生物显微镜(UBM)等检查,并记录IOL的位置及术后并发症等情况。结果:纳入患者均成功植入SFCTR和囊袋内IOL。术后平均随访1.92±1.36 a,末次随访时,UDVA(0.20±0.18 LogMAR)和CDVA(0.16±0.17 LogMAR)均较术前UDVA(1.13±0.56 LogMAR)显著改善(P<0.01),眼压(17.64±3.67 mmHg)较术前(22.00±9.92 mmHg)降低(P<0.05)。随访期间,裂隙灯检查见IOL位于囊袋内,位置居中;UBM检查见CTR和IOL位于囊袋内,囊袋赤道部与睫状突的距离在各个方向相等。结论:SFCTR植入联合晶状体超声乳化吸除加IOL植入术是治疗外伤性晶状体半脱位的一种微创有效的手术方法。

超声乳化联合囊袋张力环及人工晶状体植入术治疗高度近视合并白内障

目的:观察超声乳化联合囊袋张力环及人工晶状体植入术治疗高度近视合并白内障患者的疗效。方法:回顾性研究。选取2021-12/2023-04我院白内障科收治的高度近视合并白内障患者82例82眼,根据术中是否使用囊袋张力环分为两组:对照组39眼采用单纯超声乳化联合人工晶状体植入术治疗,联合组43眼采用超声乳化联合囊袋张力环及人工晶状体植入术治疗。比较两组患者手术前后最佳矫正视力、中央前房深度、小梁睫状突距离、视觉质量和并发症。结果:术后1mo,两组患者的最佳矫正视力(LogMAR)较术前明显改善(联合组:0.64±0.28 vs 0.12±0.14;对照组:0.62±0.26 vs 0.23±0.25,均P<0.001);中央前房深度均高于术前(联合组:2.57±0.56 vs 1.97±0.40 mm;对照组:2.22±0.45 vs 1.89±0.37 mm,均P<0.001),联合组最佳矫正视力和中央前房深度优于对照组(均P<0.05);两组患者手术前后小梁睫状突距离比较均无差异(联合组:0.68±0.22 vs 0.74±0.20 mm;对照组:0.74±0.19 vs 0.78±0.17 mm,均P>0.05)。术后1 mo视觉质量评分联合组均高于对照组[看电视3.00±0.38 vs 2.22±0.46分;看书2.85±0.42 vs 2.21±0.44分;夜间视物:2.71±0.34 vs 2.37±0.41分;精细操作2.82±0.38 vs 2.33±0.40分,均P<0.001]。联合组并发症发生率显著低于对照组(33%vs 14%,P<0.05)。结论:超声乳化联合囊袋张力环及人工晶状体植入术治疗高度近视合并白内障患者能有效促进患者视功能恢复,改善房角结构,降低并发症发生率。

改良囊袋张力环联合囊袋内人工晶状体植入治疗马方综合征晶状体不全脱位术后人工晶状体脱位的临床特征及手术治疗

目的观察接受改良囊袋张力环(MCTR)联合囊袋内人工晶状体(IOL)植入治疗的马方综合征(MFS)晶状体不全脱位患者术后IOL脱位的发生率,并总结接受IOL复位或取出术MFS患者的临床特征。方法通过随访观察2015年1月—2020年6月于我院同一手术医师行MCTR植入术且术后随访3年以上的MFS患者术后IOL脱位情况,计算其IOL脱位发生率。通过回顾分析我院同期就诊的MFS合并IOL脱位患者的临床资料,分析其临床特征和手术选择。结果本研究共纳入同一手术医师行MCTR植入术患者115例(192眼),大部分患者为儿童(80.21%,154/192),中位随访时间4年(四分位范围:3.50,4.67)。随访期间共出现MCTR-IOL复合体脱位3例(3眼),脱位发生率为1.56%(3/192),其中2例为不全脱位、1例为全脱位。3例患者均为成人,IOL脱位发生时间为术后2~3年,均无明显诱因,直接原因均为缝线断裂。同期在我院接受IOL复位或取出术的MFS患者共16例。IOL脱位最常见的直接原因是缝线断裂(62.50%,10/16)、其次是缝线或可植入式囊袋拉钩在巩膜层间出现滑动松脱(18.75%,3/16)。对于出现不全脱位的CTR或MCTR患者,通过缝线再次固定张力环或植入囊袋拉钩可实现IOL复位;MCTR脱位进入玻璃体腔的患者接受了MCTR取出和经巩膜后房型IOL缝线固定术;对于其他手术方式的IOL脱位患者,多数患者实现了脱位IOL复位术(54.55%,7/13),少数患者进行了IOL置换术(30.77%,4/13),2例IOL取出后未植入IOL。结论MCTR植入术是治疗MFS合并晶状体不全脱位的一种安全、有效的手术方式,IOL脱位是其罕见并发症。MFS患者术后定期随访十分必要,甚至需要终生随访,早期干预IOL脱位可以取得较好的疗效。

超声乳化白内障摘出联合囊袋张力环植入术治疗高度近视伴白内障的效果及对人工晶体稳定性、视力状态的影响

目的分析超声乳化白内障摘出联合囊袋张力环植入术治疗高度近视伴白内障的效果。方法选择2019年2月至2022年3月收治的90例高度近视伴白内障患者为研究对象,以随机数字表法将其分为对照组和观察组,各45例。对照组接受超声乳化白内障摘出治疗,观察组在对照组基础上加施囊袋张力环植入术治疗。比较两组的治疗效果。结果术后6个月,观察组的最佳矫正视力(BCVA)、角膜内皮细胞密度、六边形细胞百分率高于对照组,中央角膜厚度小于对照组(P<0.05)。术后3、6个月,观察组的晶体偏心量、倾斜角小于对照组(P<0.05)。术后6个月,观察组的三叶草像差、总高阶像差、球差、彗差优于对照组(P<0.05)。观察组的术后并发症总发生率低于对照组(P<0.05)。结论超声乳化白内障摘出联合囊袋张力环植入术治疗高度近视伴白内障可提高人工晶体稳定性,改善角膜质量,还能降低术后并发症发生风险,促进视力恢复,值得推广。

大型储液罐内外基础环墙抗不均匀沉降性能分析

大型储液罐对地基沉降变形非常敏感,需要采用基础环梁来防止其对上部结构的危害,因此,基础环梁设计是大型储罐建设的重要一环。本文采用有限元软件对大型储罐-基础环梁-地基土层的共同作用进行了数值模拟,主要考察了大型储油罐基础环墙环向拉力的分布,探讨了影响环墙受力的主要因素。研究表明,垫层参数对环墙环向拉力的影响较大,压缩性低,抗剪强度大并经过压实处理的垫层材料对应的环墙环向拉力最小,环墙环向拉力随环墙半径的增大先近似线性增加而后略微减小。

飞秒激光辅助超声乳化白内障摘除联合CTR植入治疗高度近视白内障

目的飞秒激光辅助超声乳化白内障摘除联合CTR植入治疗高度近视白内障术后的疗效分析及安全性评价。方法收集2019年1月至2021年11月于我院行白内障手术的高度近视白内障患者共52例。随机分成两组:飞秒组和传统组各26例。飞秒组行FLACS+CTR,传统组行超声乳化+CTR。观察术前、术后1天、1周、1月裸眼远视力、MTF、主观视觉质量量表评分、DLI值,IOL偏心量、屈光漂移量及术后并发症发生情况。结果1.术后飞秒组1d、1w、1m的UCVA-D分别为4.62±0.37、4.59±0.43、4.64±0.43较传统组4.58±0.43、4.58±0.43、4.65±0.49视力提升更显著,差异有统计学意义(P<0.05)。2.两组术后眼压飞秒组19.38±2.99较传统组18.40±3.83无明显差异(P>0.05)。飞秒组术后DLI9.04±1.30较对照组7.99±1.52比较差异无统计学意义(P>0.05)。3.术后1m人工晶体偏心量飞秒组0.13±0.09明显小于传统组0.20±0.17,差异有统计学意义(P<0.05);术后1m屈光漂移飞秒组0.28±0.12较传统组0.95±0.27差异有统计学意义(P<0.05)。4.术后1月MTF-AH飞秒组0.54±0.19较传统组0.25±0.06明显提高,差异有统计学意义(P<0.05)。5.术后1月主观视觉质量评分飞秒组4.77±0.42传统组1.42±0.57差异有统计学意义(P<0.05)。6.术后角膜水肿情况飞秒组明显少于传统组,差异有统计学意义(P<0.05)。结论飞秒激光辅助超声乳化白内障摘除联合CTR植入治疗高度近视白内障安全有效高、并发症少、并能获得较好的视觉质量。

DFT法研究三聚甲醛开环聚合热力学

开环聚合是高分子化学的重要组成部分,环醚的开环聚合反应是开环聚合反应中具有代表性的一类。本文利用DFT方法,使用高斯量子化学计算软件,通过对1,3-二氧六环、1,4二氧六环、1,3,5-三氧六环等单体的结构优化和能量计算,获得了这些单体的结构数据和开环聚合的热力学数据。计算结果表明:三元环、四元环状单体张力较大,开环聚合倾向较大。六元环中,1,3,5-三氧六环由于氧原子斥力较大,能量较高易于开环。

疝环填充式无张力疝修补术与传统疝修补术在腹股沟疝治疗中的疗效比较

目的 探讨疝环填充式无张力疝修补术与传统疝修补术在腹股沟疝治疗中的疗效。方法 纳入2018年1月至2022年12月期间在我院普外科就诊的腹股沟疝患者76例,根据随机数字表法分组,对照组(38例)进行传统疝修补术治疗,观察组(38例)进行疝环填充式无张力疝修补术治疗,对比两组临床疗效、并发症发生情况、手术及术后恢复情况、视觉模拟评分量表(VAS)评分、术后复发率。结果 观察组的治疗总有效率为94.74%,高于对照组的78.95%(P <0.05);观察组的并发症发生率、术后2 h、术后第3天、术后第7天的VAS评分以及复发率均低于对照组(均P <0.05);观察组所需的手术时间、下床活动时间、住院时间、切口疼痛消失时间等手术及术后恢复指标均短于对照组(P <0.05)。结论 对腹股沟疝患者采取疝环填充式无张力疝修补术的疗效显著,可减轻术后疼痛感,缩短住院时间,促进患者早日康复。