Oxygen permeability of soft contact lenses in different pH, osmolality and buffering solution

AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH increments to a pH in the range of 5.8-9.0 or in hypotonic (280 mOsmol/kg), isotonic (310 mOsmol/kg) and hypertonic (380 mOsmol/kg) PBS solutions. Polarographic method was used for measuring the Dk and lenses were stacked as 4 layers to correct the boundary effect.RESULTSDk values of all contact lenses measured in BBS solutions were more stable than those in PBS solutions. Especially the etafilcon A lens showed a relative big change compared with other types of contact lenses at the same conditions. When the osmolality of PBS solution increased from hypotonic to hypertonic, Dk of all contact lenses decreased. Variations in Dk existed depending on lens materials, etafilcon A lens was the most affected and nelfilcon A was the least affected by osmolality.CONCLUSIONFrom the result obtained, it is revealed that Dk of contact lenses is changed by the pH, osmolality, and buffering condition of tear. Thus, Dk of contact lens can be varied by the lens wearers' physiological and/or pathological conditions.

Efficacy of custom-made soft keratoconus lenses on corneal aberrations and photic phenomena in patients with keratoconus:a corneal topography imaging based study

AIM:To evaluate the efficacy of custom-made soft keratoconus(KC)lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.METHODS:Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone(Toris K)soft silicone hydrogel lenses.Best spectacle-corrected visual acuity(BSCVA)and contact lens-corrected visual acuity(CLCVA)were recorded.Lower-and higher-order corneal aberrations(LOAs and HOAs)were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones.Mesopic pupil diameter and subjective photic phenomena were also assessed.RESULTS:Mean CLCVA was significantly improved compared to BSCVA(P<0.0001).Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses,except for posterior corneal curvature values.In the 4.5 mm central optical zone,all wavefront aberrations decreased significantly after lens fitting(P<0.0001).In contrast,in the 7 mm(peripheral)optical zone,values for HOAs,spherical and residual aberrations,and optical path differences were increased,while LOAs,trefoil,and quadrifoil coefficients were decreased.The rate of photic phenomena was significantly higher in participants with a pupil size>6.00 mm(85.7%).CONCLUSION:Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations.This practical and nonsurgical approach appears to be an effective method for the visual management of KC.

Effectiveness of toric soft contact lenses for vision correction in patients with different degrees of astigmatism: a real-world study

AIM:To assess the visual correction of patients with different degrees of astigmatism with toric soft contact lenses(TSC).METHODS:It was a real-world study with prospective and single-arm design.A total of 384 patients with astigmatism who came for TSC fitting and alignment from November 2022 to January 2023 were included.According to the difference in astigmatism,patients were divided into groups A(cylinder degree:-0.75 to-0.50 D),B(cylinder degree:-1.75 to-1.00 D)and C(cylinder degree≤-2.00 D),and followed up on the day of wear,1wk,1 and 3mo,mainly to observe visual acuity,refraction,lens fit,visual quality and comfort at 1wk after wear.The visual acuity success rate and the overall success rate of the fitting were evaluation indicators(taking into account the four dimensions of visual acuity,fitting,quality of vision and comfort).The visual acuity success rate was calculated by taking“corrected visual acuity with contact lenses is no less than 1 line or better than best spectacle-corrected visual acuity”(i.e.corrected visual acuity with contact lenses is 1 line below,equal to,one line above or more than best spectaclecorrected visual acuity)as the criterion for visual success,and the the overall success rate of the fitting was calculated by using the comprehensive indicators(visual acuity,fit,visual quality,comfort)to meet certain conditions as the judgment criteria for successful fitting.RESULTS:After 1wk of wearing TSC,the visual acuity success rates of patients were 100%(207/207),98.58%(139/141)and 97.22%(35/36)in the three groups,respectively,with residual cylinder closed to 0.The acceptability of the lens fitting was over 95%;the incidence of adverse visual symptoms was within 10%and the comfort acceptability was over 97%.The overall success rate of fitting for patients with high,medium and low astigmatism was 93.72%(194/207),90.78%(128/141)and 88.89%(32/36),respectively.CONCLUSION:TSC(model:G&G POP·CT)are effective in correcting astigmatism in patients with different degrees of astigmatism.

Corneal Wavefront Aberrations in Patients Wearing Multifocal Soft Contact Lenses for Myopia Control

Purpose: The purpose of this study was to evaluate the change in corneal wavefront aberrations in young adults who have been fit with multifocal soft contact lenses for myopia progression control. Findings have been analyzed for statistical significance and clinical relevance and compared to reportedly successful Orthokeratology outcomes. Methods: The dominant eye of 40 participants (27 women, 13 men;mean age 27.3 ± 3.2 years;range 23 to 39 years) was fit with Proclear Multifocal center distance lenses (Coopervision, Pleasanton, USA) having a variety of distance powers and reading additions. Refractive errors were limited to a range of –6.00 D up to +1.00 D of sphere, and no greater than –1.00 D of cylinder. Corneal wavefront measurements were performed over 6 mm diameters with a Zeiss Atlas 9000 corneal topographer (Zeiss Meditec, Dublin, USA) prior to, and following lens fitting. Data were converted into rectangular Fourier optics terms M, J0, J45 and RMS values for each reading addition were statistically analyzed. Following evaluation of statistical significance and clinical relevance, results were compared to published data from successful Orthokeratology treatments. Results: Statistically significant changes in higher order aberrations were detected for lenses of all reading additions. Lens groups with higher Add-powers demonstrated stronger changes with increased significance. Final RMS values relating to 2nd, 3rd and 4th Zernike Orders reached clinical significance with a wavefront error of 0.10 μm, the equivalent of 0.25D. Moreover, as Add-powers increased, 3rd and 4th order aberrations likewise showed an increase. Pre-fitting astigmatism values accounted for the highest recorded aberrations and remained predominantly unchanged. Conclusion: Proclear Multifocal center-distance contact lenses were found to increase higher order wavefront aberrations in a manner dependent on their Add-power. In comparison to successful Orthokeratology outcomes, the amounts of resulting aberrations are notably different.

Is the Use of Empirically Designed Custom Soft Contact Lenses a Good Option for Challenging Patients?

Purpose: Reasons for the lack of success for contact lens patients range from poor fit, to discomfort or to a less than optimum wearing schedule. This project was a preliminary investigation of customized soft toric contact lenses as an alternative for unsuccessful contact lens patients or potential drop-outs. Methods: Fifteen healthy non-compromised, previously unsuccessful contact lens wearing patients (13 women, 2 men) with ages from 21 to 33 years (25.1 ± 2.7 years) were the subjects for this study. They were empirically fitted with 15 astigmatic and 5 spherical customized SpecialEyes soft contact lenses. Visual acuities, comfort, lens movement, and rotation were evaluated. Results: Patients fitted with customized SpecialEyes soft contact lenses had statistically significant better visual acuities than with Phoropter Manifest Refraction. The lenses used in this study centered well and moved no more than 1 mm upon each blink. Lens rotation was less than 10 degrees for all toric lenses. Patients gave very positive vision and comfort ratings. Conclusion: This preliminary study supports the application of a software program to empirically design and manufacture Special Eyes custom soft lenses based upon corneal topographical parameters and subjective manifest refraction for those patients who either have challenging corneal parameters, high sphero-cylindrical prescriptions, or are currently dissatisfied with their contact lenses and are potential drop-outs.

周边离焦软镜对高度近视儿童眼睛调节功能的影响

目的研究佩戴周边离焦软镜高度近视儿童眼睛调节功能变化。方法收集采用周边离焦软镜进行近视矫正的高度近视儿童27例(54只眼)作为观察组,选取同期与观察组年龄、性别、屈光状态相匹配的单焦框架眼镜佩戴者27例(54只眼)作为对照组。观察2组患者经过不同矫正方式1年后其单眼调节幅度、正/负相对调节、调节滞后量、单眼调节灵敏度和双眼调节灵敏度的变化。结果观察组的单眼调节幅度、正相对调节、单眼及双眼的调节灵敏度较对照组增加,调节滞后量较对照组减小,差异有统计学意义(P<0.05);2组患者的负相对调节差异无统计学意义(P>0.05)。结论在高度近视患儿中,佩戴周边离焦软镜可以改善眼睛调节功能,可作为延缓高度近视进展的有效方式之一。

离焦软镜的安全性及其在近视防控中的研究进展

近视是危害全世界眼健康的常见眼科疾病,我国近视发病率较高,近视成为影响青少年眼健康最突出的问题,近视防控工作已刻不容缓。周边视网膜远视性离焦是导致近视的主要原因之一,基于此种原理设计的离焦软镜在近视防控中起到了较好的作用。文章总结了离焦软镜控制近视的原理及其对角膜、视功能的影响,并基于当前研究评价离焦软镜对近视的防控作用。

探讨角膜塑形镜、周边离焦软镜对8~10岁儿童近视控制疗效比较

目的 探究8~10岁儿童使用角膜塑形镜(Ortho-k)和周边离焦软镜(DISCs)对近视防控效果比较。方法 前瞻性非随机临床对照研究。将儿童分为Ortho-k组和DISCs组,观察其在近视防控方面的效果。观察两组患者的等效球镜(SE)及眼轴(AL)变化特点。结果 6月随访:两组的平均SE分别为(-3.30±1.27)D、(-3.09±1.31)D,平均AL分别为(24.83±0.89)mm、(24.75±0.94)mm。1年随访:两组的平均SE分别为(-3.49±1.24)D、(-3.32±1.29)D,平均AL分别为(24.96±0.88)mm、(24.92±0.92)mm。随访中:两组的SE和AL均有所增加,但差异无统计学意义。结论 本研究发现两种近视矫正方式在近视防控中具有相似疗效。

斜仰卧截石位单通道经皮肾镜联合经皮软镜治疗复杂肾结石的疗效观察

目的观察斜仰卧截石位单通道经皮硬性肾镜联合经皮肾软镜治疗复杂上尿路结石的临床效果。方法 2013年5月-2016年1月于该院住院的肾多发结石及鹿角状结石患者,其中40例行斜仰卧截石位球囊扩张建立标准通道,单通道经皮硬镜与经皮软镜联合碎石,分析患者临床资料,包括手术时间,出血量、结石清石率、住院时间和手术并发症发生情况等指标。结果该组患者均I期单通道顺利实施手术,手术中位时间52.5 min,结石清石率100%、手术前后出血量变化无差异,患者无需输血,随访3~6个月,无明显手术并发症发生。结论斜仰卧截石位单通道经皮硬镜联合经皮软镜治疗复杂肾结石,可提高结石清除率,增加患者术中舒适感,避免多通道对肾脏的损伤,手术时间短,治疗效果明显。

标准经皮肾镜联合膀胱软镜治疗肾结石对于血清同型半胱氨酸和β2-微球蛋白的表达影响

目的探讨标准经皮肾镜联合膀胱软镜治疗肾结石对于血清同型半胱氨酸和β2-微球蛋白的表达影响。方法 2011年8月到2015年3月选择肾结石患者140例,根据随机抽签方法分为治疗组与对照组各70例,对照组采用肾实质切开取石术,治疗组采用标准经皮肾镜联合膀胱软镜治疗。对比观察两组围手术指标、并发症、肾功能、血清同型半胱氨酸和β2-微球蛋白水平。结果所有患者一次性清除结石,不过治疗组的手术时间、术中出血量、胃肠道功能恢复与术后住院时间都明显少于对照组(P<0.05)。治疗组术后14 d的肺部感染、肺不张、继发性出血、肠梗阻等并发症发生情况明显少于对照组(P<0.05)。两组术后14 d的血肌酐含量(92.44±10.33)μmol/L和(103.87±8.22)μmol/L,都明显高于术前的(67.44±9.87)μmol/L和(68.13±10.42)μmol/L(P<0.05),同时组间对比差异也有统计学意义(P<0.05)。两组术后14 d的血清同型半胱氨酸和β2-微球蛋白都呈现明显下降的趋势(P<0.05),同时术后14 d的血清同型半胱氨酸和β2-微球蛋白明显低于对照组(P<0.05)。结论标准经皮肾镜联合膀胱软镜治疗肾结石能降低血清同型半胱氨酸和β2-微球蛋白水平,有利于保护肾功能,减少术后并发症的发生。

角膜接触镜对PRK术后角膜上皮愈合的影响

目的 评价亲水性软性角膜接触镜对PRK术后角膜上皮愈合的影响。方法 对 91例低中度近视病例分为戴镜组 (Ⅰ组 )和包眼组 (Ⅱ组 ) ,观察PRK术后角膜上皮愈合情况、角膜刺激症状及视力。结果 角膜上皮愈合时间 :Ⅰ组平均为 2 37± 0 73天 ,Ⅱ组为 3 96± 1 0 5天 (P <0 .0 5 ) ;48小时内愈合者分别为 92 5 5 %和 80 5 9%。角膜刺激症 :+～ + +者Ⅰ组和Ⅱ组分别为 6 5 96 %和 17 6 5 % ,≥ + + +者分别为 33 86 %和 72 35 %。术后 7天裸眼视力 :≥ 0 .5者两组分别为 98 94%和 98 82 % ,但≥ 1 0者分别为 5 2 13%和 9 41%。

水凝胶软性亲水接触镜临床应用及安全性

背景:采用水凝胶材料制作而成的Extra-Care软性亲水接触镜含水量、透氧系数、折射率等指标均已达到国家标准。目的:通过与已上市的同类产品TB软性隐形眼镜对比,评价Extra-Care软性亲水接触镜的有效性和安全性。方法:将135例近视眼志愿者随机分入配戴Extra-Care软性亲水接触镜组(试验组)与配戴TB软性隐形眼镜组(对照组)。所有受试者在入选当天、使用7d、使用30d、使用90d时进行视力清晰程度、视力稳定性、配戴舒适度、镜片中心定位、镜片覆盖、眼部异物感、角巩膜缘充血和角膜点状染色及泪膜破裂时间检查。结果与结论:两组视力清晰程度、视力稳定性、镜片中心定位、镜片覆盖、眼部异物感、角巩膜缘充血和角膜点状染色及泪膜破裂时间差异无显著性意义,但试验组舒适度优于对照组(P<0.05)。表明Extra-Care软性亲水接触镜的临床应用是有效和安全的,并提高了配戴舒适度。

PRK术后应用亲水性软性角膜接触镜的临床观察

目的 观察亲水性软性角膜接触镜在准分子激光屈光性角膜切削术 (PRK)后的临床效果。 方法 将双眼屈光状态基本相同,屈光度为-1 00^-6 00D,进行近视PRK矫正的患者 148例,分为术后戴角膜接触镜 3d与不戴两组。观察记录术后 3d的角膜上皮愈合情况、疼痛程度、角膜上皮下混浊程度。术后平均随访半年。 结果 戴镜组术后2d内角膜上皮完全愈合率为 68%,对照组为 24% (P<0 05 )。戴镜组疼痛 0 5级、1级、2级的发生率分别为 58%、20%、22%,对照组为 0、54%、45% (P<0 05)。戴镜组术后 1、3、6个月的角膜haze发生率分别为 50%、32%、14%,对照组为 83%、70%、35% (P<0 05)。 结论 亲水性软性角膜接触镜可明显减轻PRK术后疼痛等刺激症状,促进角膜上皮愈合,使角膜haze发生减少和程度减轻,表明PRK术后角膜创面覆盖及上皮快速愈合是减轻haze发生的重要条件之一。

不同光学矫正方式对人眼单色波前像差的影响

目的通过测量波前像差,研究不同光学矫正方式(框镜和角膜接触镜)对人眼光学性能的影响。方法使用客观波前像差仪测量29人55只近视眼在5种矫正下的波前像差:裸眼(UC)、硬性透氧性角膜接触镜(硬镜)、软性角膜接触镜(软镜)、框架眼镜(框镜)和框镜等效球镜(等效框镜)。光学矫正镜片为球面设计。采用波前像差的均方根(RMS)值和Zernike像差进行计算。每次测量重复3次,取均值分析。结果硬镜矫正的均方根值最小。与裸眼状态相比,软镜矫正的均方根值增加,而硬镜矫正和框镜矫正的均方根值显著减少(F=11.90,P<0.002;F=4.75,P<0.05)。高阶像差中,戴硬镜矫正的均方根值比裸眼、戴软镜和戴框镜矫正都显著减少(F=6.18,P<0.02;F=20.73,P<0.001;F=25.51,P<0.001),而戴软镜和戴框镜矫正的均方根值比裸眼状态都显著增加(F=4.98,P<0.05;F=7.86,P<0.01)。对于中度散光眼,戴软镜矫正会显著增加裸眼状态的均方根值(F=4.87,P<0.05)。戴软镜会引起高阶Zernike像差显著增加;戴框镜显著减少了2阶散光的Zernike像差,戴硬镜则显著减少2至4阶Zernike像差。结论戴软镜矫正增加高阶像差,戴框镜矫正减少低阶像差,戴硬镜矫正减少整眼像差。对于波前像差小的裸眼,由于光学镜片矫正打破了屈光介质之间波前像差的平衡,眼像差增加。球性软镜和不规则角膜表面间厚度不均的泪液层会使中度散光眼的像差显著增加。戴硬镜、软镜和框镜矫正均显著降低初级球差。

输尿管硬镜联合软镜钬激光碎石术治疗复杂上尿路结石的临床研究

目的探讨输尿管硬镜联合软镜钬激光碎石术治疗复杂上尿路结石的临床效果。方法方便选取2011年5月—2015年6月在该院接受治疗的60例上尿路结石患者作为研究对象。对患者进行随机分组,对照组30例给予输尿管硬镜联合体外碎石术治疗,观察组30例给予硬镜联合软镜钬激光碎石术治疗,对比分析两组患者的碎石成功率、复发率及手术情况。结果经治疗,观察组排石率为96.67%,对照组为70.00%,观察组明显高于对照组;观察组患者碎石成功率为93.33%,对照组为73.33%,观察组显著高于对照组;复发率明显低于对照组,两组间对比差异有统计学意义(P<0.05)。观察组平均手术时间、住院时间、出血量及排石时间均明显少于对照组,比较差异有统计学意义(P<0.01)。结论输尿管硬镜联合软镜钬激光碎石术治疗复杂上尿路结石的效果明显优于硬镜钬激光碎石术,值得临床推广及应用。

配戴亲水软性角膜接触镜治疗青光眼大疱性角膜病变

目的：评价配戴亲水软性角膜接触镜治疗绝对期青光眼导致的大疱性角膜病变的疗效及安全性。方法：给５６ 例５６ 眼因年老体弱，不能或不愿手术治疗而症状明显的绝对期青光眼大疱性角膜病变患者长期连续配戴软性角膜接触镜治疗，并戴镜滴用抗生素及皮质类固醇眼液。结果：大疱性角膜病变症状在戴镜后１ ～３ 天内明显改善者９８．２％ ，１ 周内均解除者９６．４％ 。有８９．２％ 的病例连续戴镜不取出超过３ 个月，平均８ ．８±１０．２ 个月。仅３２．１％ 的患眼出现角膜新生血管，未见继发感染者。结论：连续配戴亲水软性角膜接触镜能解除绝对期青光眼所致的大疱性角膜病变症状，且安全、简便、易行，尤其适用于不能或不愿接受手术治疗的患者。

Extra-Care软性亲水接触镜临床应用的有效性和安全性

目的评价Extra-Care软性亲水接触镜的有效性和安全性.方法选择135例近视眼志愿者,平均年龄(22.49±1.26)岁,所有志愿者签署知情同意书后按照随机数字表方法随机分为配戴Extra-Care软性亲水接触镜组(A组)和配戴NB软性隐形眼镜组(B组).所有的受试者在入选当天、使用7 d、使用30 d、使用90 d时进行眼部和软性亲水接触,镜检查视力清晰程度、视力稳定性、镜片的中心定位,以及安全性评价指标.结果A组和B组差异无统计学意义(P>0.05).结论Extra-Care软性亲水接触镜的临床应用是有效和安全的.

评价接触镜除蛋白护理液去蛋白的试验方法

利用人工泪液浸泡镜片．模拟蛋白吸附．采用紫外分光光度计在波长280 nm处测试经护理液洗脱的蛋白质的吸光度, 计算蛋白质含量。测试除蛋白护理液对软性角膜接触镜上的蛋白质沉淀的洗脱效果。结果除蛋白含量的测试结果具有重复性。该试验方法可以对除蛋白护理液的洗脱率效果进行评价,但尚需完善．

输尿管软镜手术前患者留置双J管期间的居家管理

目的对拟行输尿管软镜手术前留置双J管居家休养患者进行护理干预。方法通过成立专业小组和建立管理档案,对患者在离院前后进行评估和健康教育,掌握患者遵医行为,对其实施规范居家管理。结果患者居家休养和住院治疗得到同样的护理管理,保证患者安全。结论弥补了患者居家休养期间的护理缺失,保证患者能按预期接受手术。

动态稳定法在环曲面软镜验配中的应用研究

目的观察动态稳定法设计环曲面软镜的临床应用表现，并探讨其旋转量、稳定性的影响因素。方法为191例（191只眼）散光自愿者验配动态稳定法设计环曲面软镜，记录右眼的矫正视力、镜片配适评估、旋转量、稳定性及患者的主观评价、安全性分析。结果（1）动态稳定法设计型环曲面软镜的矫正视力与主觉验光的最佳矫正视力无差异。（2）156只眼（81．68％）中心定位正中，140只眼（83．3％）活动度理想，覆盖度均良好。（3）镜片旋转量以向颞侧偏转0—5°最多，有40只眼（20．94％），镜片稳定性为0—5°者有143只眼（74．87％）。（4）初戴时106人（55．50％）诉有轻至中度异物感，145人（75．92％）诉该镜片容易配戴。（5）随访3个月内未发现明显眼部病变。结论在合理筛选患者的前提下，动态稳定法设计环曲面软镜能为散光患者提供有效、安全、舒适的屈光矫正。