Sutured scleral fixation of existing subluxated/dislocated acrylic one-piece intraocular lenses

AIM:To evaluate the visual and refractive outcomes in cases after sutured scleral fixation of existing subluxated or dislocated acrylic one-piece intraocular lenses(IOLs).METHODS:This study retrospectively enrolled a consecutive series of patients who underwent a surgery of sutured existing subluxated or dislocated IOLs from October 2018 to June 2020.All patients underwent comprehensive preoperative and postoperative ophthalmologic examination,and data were collected including age,sex,surgical indications,best-corrected visual acuity,refractive error,intraocular pressure.Presence of intraoperative and postoperative surgical complications was documented.RESULTS:A total of 20 consecutive cases were enrolled for analysis with mean final follow-up period 9.8±5.3mo.Visual acuity improved from a mean of 0.35(0.46±0.32 logMAR)preoperatively to 0.61(0.21±0.18 logMAR)at the 3-month follow-up(P=0.002).The mean amount of preoperative keratometric astigmatism and total postoperative refractive astigmatism was-1.24±0.80 diopters(D)and-1.42±0.97 D,respectively.There was no statistically significant difference between preoperative and postoperative astigmatism(P=0.156).The mean IOL-induced astigmatism was-0.23±0.53 D.The mean spherical equivalent at the 3-month follow-up was-0.1±0.94 D.No major complications were noted during the follow-up period.CONCLUSION:Surgical techniques using sutured scleral fixation of existing subluxated or dislocated acrylic one-piece IOLs result in favorable visual and refractive outcomes without major complications.

Changes in visual performance after implantation of different intraocular lenses

AIM:To evaluate the trending visual performance of different intraocular lenses(IOLs)over time after implantation.METHODS:Ninety-one patients received cataract surgery with implantations of monofocal(Mon)IOLs,segmental refractive(SegRef)IOLs,diffractive(Dif)IOLs,and extendeddepth-of-focus(EDoF)IOLs were included.The aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and compared.RESULTS:Most of the visual parameters improved over the postoperative 6mo.The postoperative visual acuity(POVA)of the Mon IOL,SegRef IOL,and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL group.Nevertheless,the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative 6mo.The optical quality initially improved in the EDoF IOL group,then in the Mon IOL,SegRef IOL,and Dif IOL groups.POVA and objective visual performance of the Mon IOL and EDoF IOL groups,as well as POVA and visual quality of the Dif IOL group,improved in the postoperative 1mo and stabilized.Within the postoperative 6mo,gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group,as well as in the postoperative optical quality of the Dif IOL group.CONCLUSION:The visual performance is different among eyes implanted with different IOLs.The findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

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.

Flapless one-knot suture:a novel surgical technique for transscleral fixation of C-loop intraocular lenses

AIM:To describe a novel suture approach for transscleral fixation of C-loop intraocular lenses(IOL)and to compare the surgical outcomes with the four-haptics posterior chamber(PC)-IOL technique.METHODS:We retrospectively analyzed 16 eyes of 16 patients who underwent transscleral fixation of C-loop PCIOLs using a flapless one-knot suture technique,which were followed up for longer than 17mo.In this technique,the capsulorless IOL was suspended using a single suture for transscleral fixation of four feet.Then we compared its surgical outcomes and complications with the four-haptics PC-IOLs using the Student's t test and Chi-square test.RESULTS:Sixteen patients of 16 eyes with a mean age of 58.3±10.1y(42-76y)who received transscleral C-loop IOL implantation due to trauma,vitrectomy,or cataract surgery with inadequate capsule support showed improved visual acuity.The difference was not significant between two IOLs except the surgery time(P>0.05).The mean operation times of C-loop IOL surgery was 24.1±1.83min and 31.3±4.47min of the four-haptics PC-IOL method(P<0.0001).In the C-loop IOLs group,there was statistical difference between the preoperative and the postoperative UCVA(log MAR,1.20±0.50 vs 0.57±0.32,P=0.0003).There was no statistical difference between the preoperative and the postoperative BCVA(log MAR,0.66±0.46 vs 0.40±0.23,P=0.056).However,there was no statistically significant difference in postoperative UCVA and BCVA between the two IOLs(P>0.05).We did not detect any optic capture,IOL decentration or dislocation,suture exposed,or cystoid macular edema in patients underwent C-loop IOLs surgery.CONCLUSION:The novel flapless one-knot suture technique for transscleral fixation of C-loop IOL is a simple,reliable,and stable technique.

A new software for automated counting of glistenings in intraocular lenses in vivo

AIM:To assess the performance of a bespoke software for automated counting of intraocular lens(IOL)glistenings in slit-lamp images.METHODS:IOL glistenings from slit-lamp-derived digital images were counted manually and automatically by the bespoke software.The images of one randomly selected eye from each of 34 participants were used as a training set to determine the threshold setting that gave the best agreement between manual and automatic grading.A second set of 63 images,selected using randomised stratified sampling from 290 images,were used for software validation.The images were obtained using a previously described protocol.Software-derived automated glistenings counts were compared to manual counts produced by three ophthalmologists.RESULTS:A threshold value of 140 was determined that minimised the total deviation in the number of glistenings for the 34 images in the training set.Using this threshold value,only slight agreement was found between automated software counts and manual expert counts for the validating set of 63 images(κ=0.104,95%CI,0.040-0.168).Ten images(15.9%)had glistenings counts that agreed between the software and manual counting.There were 49 images(77.8%)where the software overestimated the number of glistenings.CONCLUSION:The low levels of agreement show between an initial release of software used to automatically count glistenings in in vivo slit-lamp images and manual counting indicates that this is a non-trivial application.Iterative improvement involving a dialogue between software developers and experienced ophthalmologists is required to optimise agreement.The results suggest that validation of software is necessary for studies involving semi-automatic evaluation of glistenings.

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.

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.

Rotational stability of plate haptic toric intraocular lenses after combined 25-gauge vitrectomy and cataract surgery

AIM:To evaluate the postoperative intraocular lens(IOL)rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL.METHODS:In this retrospective case series,32 eyes of 32 patients underwent a combined 25-gauge vitrectomy and phacoemulsification for vitreoretinal diseases and cataract with regular corneal astigmatism of at least 1 diopter(D).A plate haptic toric IOL(AT Torbi 709M,Carl Zeiss Meditec AG)was implanted in all eyes.The outcome measures were rotational stability and refractive astigmatism up to 6mo postoperatively as well as the best corrected visual acuity(BCVA).RESULTS:Preoperative refractive astigmatism was 2.14±1.17 D,which was significantly reduced to 0.77±0.37 D six to eight weeks postoperatively and remained stable throughout the observation period(0.67±0.44 D at three months and 0.75±0.25 D at six months;for all groups:P<0.0001 compared to baseline).BCVA improved significantly from 0.36±0.33 logMAR preoperatively to 0.10±0.15 logMAR following surgery(P=0.02).Mean IOL axis deviation from the target axis was 3.4°±2.9°after six to eight weeks and significantly decreased over time(2.4°±2.6°six months after surgery;P=0.04).In one patient IOL,re-alignment was performed.CONCLUSION:Corneal astigmatism is significantly reduced following combined 25-gauge vitrectomy and cataract surgery.The plate haptic toric IOL position and axis remain stable during the observation period of six months.

Relativistic Supernova Blast Waves Exhibit Properties of Gravitational Lenses and the Hubble Constant

Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves within a million years, SNes occurring in a rarified environment outside of the ISM generate blast waves which remain in a relativistic free expansion phase for more extended periods. The SN blast wave forms an expanding spherical shell and when multiple blast waves intersect, the overlapping region naturally takes the form of a ring, an arc, or an Einstein Cross structure. The analysis shows the relativistic plasma establishes a medium with permeability which drives the index of refraction greater than 1. As a result, when a shock discontinuity forms in the overlapping region, light is reflected from the host galaxy which exposes the intersecting blast wave regions. The expanding shells are shown to induce an achromatic redshift to the reflected light consistent with those measured for gravitational lenses. Further, it is shown that a Hubble equation for a blast wave around the Milky Way Galaxy can be parameterized to approximate measured redshifts over a wide range of distances.

多区正向设计离焦框架眼镜与角膜塑形镜对儿童近视的延缓效果比较

目的比较配戴多区正向设计离焦(DIMS)框架眼镜和角膜塑形镜对儿童近视进展的延缓效果。方法采用非随机对照临床研究方法,纳入2018年1月至2020年12月于郑州大学第一附属医院就诊的近视儿童390例390眼,等效球镜度(SER)为-0.75~-6.00 D。依据患儿及其监护人意愿将受试者分为DIMS框架眼镜组、角膜塑形镜组和单光框架眼镜组,每组130例130眼,分别给予配戴DIMS框架眼镜、标准型或带散光设计角膜塑形镜及非球面设计的普通单光足矫框架眼镜,分别在戴镜前及戴镜后1年采用全自动电脑验光仪联合主觉验光测定受试眼SER;采用IOLMaster测量眼轴长度(AL)。最终符合纳入及排除标准的随访者共327例327眼,其中DIMS框架眼镜组107例107眼、角膜塑形镜组112例112眼、单光框架眼镜组104例104眼,均取右眼数据纳入分析。比较3个组受试眼戴镜前及戴镜后1年SER和AL及其变化量。DIMS框架眼镜组受试眼AL和SER变化量与基线资料的关系评估采用Pearson线性相关分析。结果DIMS框架眼镜组、角膜塑形镜组、单光框架眼镜组不同时间点SER和AL总体比较差异均有统计学意义(SER:F_(组别)=7.065,P=0.009;F_(时间)=183.730,P<0.001.AL:F_(组别)=6.151,P=0.014;F_(时间)=175.290,P<0.001),戴镜后1年3个组受试眼SER和AL变化量总体比较差异均有统计学意义(F=7.065,P=0.009;F=6.151,P=0.014),其中各组1年后SER和AL均大于基线时,角膜塑形镜组和DIMS框架眼镜组SER和AL及其变化量均明显小于单光框架眼镜组,DIMS框架眼镜组SER和AL及其变化量均大于角膜塑形镜组,差异均有统计学意义(均P<0.05)。与单光框架眼镜相比,配戴角膜塑形镜1年能分别抑制SER和AL进展58.3%和59.0%,配戴DIMS框架眼镜1年能分别抑制SER和AL进展46.9%和43.6%。戴镜1年单光框架眼镜组、角膜塑形镜组和DIMS框架眼镜组SER无变化的眼数占比分别为5.77%(6/104)、24.11%(27/112)和17.76%(19/107),AL无变化的眼数占比分别为0.00%(0/104)、8.93%(10/112)和7.48%(8/107),总体比较差异均有统计学意义(χ2=9.316、8.676,均P<0.001)。DIMS框架眼镜组AL变化量与年龄呈弱负相关(r=-0.252,P=0.006)。结论配戴DIMS框架眼镜对儿童近视的延缓效果不及角膜塑形镜,但明显优于配戴普通单光框架眼镜。

四川攀枝花大田地区铀矿化透镜地质体特征、成因及其对深源铀成矿的启示

提要:【研究目的】近期在四川省攀枝花大田地区发现了呈雁列式展布铀矿化透镜体群,无论是在铀矿化特征上还是在成因上均极为特殊,具有重要的研究价值。【研究方法】通过对铀矿化透镜体开展岩石学、矿物学、岩石地球化学、同位素地质学及年代学、铀赋存状态及铀矿化与透镜体之间的成因联系等研究。【研究结果】铀矿化透镜体基本由斜长石组成并发生了强烈钠黝帘石化,具有岩浆岩常见的镶嵌结构,形成年龄为821 Ma(SIMS锆石U-Pb)。化学组成上具有富Na_(2)O(含量3.95%~5.68%,平均为5.09%)、CaO(含量4.40%~7.35%,平均为5.46%),贫SiO_(2)(含量51.52%~55.09%,平均为53.34%)的特征。微量元素分析结果显示铀矿化透镜体具有极低的ΣREE含量(含量9.96×10^(-6)~33.63×10^(-6),平均为22.03×10^(-6)),特殊的铕正异常(δEu=1.59~5.51,平均为2.68)稀土配分模式。I_(Sr)值介于0.7060~0.7088,平均为0.7074,具有地幔来源特征。透镜体中铀主要呈独特的“铀钛矿物聚集体”形式存在,主要由“金红石+铀钛混合物+钛铀矿+晶质铀矿+锆石”等矿物组成,且上述矿物具有由“金红石(Ti)→铀钛混合物(Ti>U)→钛铀矿(Ti700℃)高压(>15 kbar)的环境中,U与Ti具有极强的亲和性,形成以Na U^(4+)(Ti^(4+))[Ti O_(4)]^(4+)(F,Cl)为主要形式的络合物,并在熔体中向富钠的部位迁移、富集。铀与透镜体具有同源、同成因特征,而“铀钛矿物聚集体”是在等压降温过程中因温度降低从浆状体中分离出来所形成。攀枝花大田地区铀矿化透镜体的发现提供了深源铀成矿的地质实例,为探讨深源铀成矿提供了参考。

渐近安全引力下的黑洞阴影和光环

重点讨论了薄盘吸积与渐近安全(asymptotically safe,AS)引力修正参数对黑洞阴影和光环的影响.对于薄盘吸积,黑洞的暗区就是黑洞的阴影,而明亮的光环则是由直接像、透镜环和光子环组成的.对于吸积盘辐射源比强度,考虑了3个不同辐射轮廓模型.对辐射起始于最内圆轨道的二阶衰减函数模型,直接像、透镜环和光子环可以明显区分.直接像对黑洞光环亮度贡献最大,透镜环对光环亮度贡献很小,而光子环的贡献几乎可以忽略,且对应观测强度的峰值随AS引力参数的增加而减小,即对应光环亮度随修正参数的增大而变暗.对于辐射起始于光子球半径的三阶衰减函数模型,透镜环和光子环叠加在直接像上,使观测强度出现新的极值.这一极值随AS引力修正参数的增加而增加,且使得黑洞光环的亮度更亮.对辐射起始于事件视界的反三角衰减函数模型,透镜环和光子环在直接像上的叠加范围更大,观测到的光环更宽,且AS引力参数值越小,透镜环和光子环越难区分,黑洞光环的亮度越大.总之,研究表明,黑洞阴影半径的大小随AS修正参数的增加而减小,对于不同的AS引力修正参数,辐射源光强度、尤其是观测强度的辐射轮廓存在显著差异,导致黑洞的阴影和亮环明显不同.

基于轻量化特征选择的镜片多尺度缺陷检测系统研究

为解决对镜片缺陷识别和定位困难的问题,设计了一种基于轻量化特征选择(LFSN)的镜片多尺度缺陷检测系统。首先通过四步相移栅格光成像系统采集缺陷图像,基于傅里叶变换对图像进行融合以提高图像质量;然后,LFSN使用自动特征层选择结构,在训练过程中计算无锚框分支损失,获得最优特征层信息,更新参数,从而优化模型对不同缺陷大小信息的学习能力;还使用了深度分离可变卷积,通过双线性插值增加像素点在平面的偏移量,从而提升模型对缺陷形貌的主动学习能力,并一定程度减少模型训练参数量,降低检测时间,同时优化回归定位损失明确各阶段训练任务,利用一次惩罚项指导前期预测框中心距离回归;利用归一化二次项,指导后期预测框大小比例回归,使预测框更接近真实值;最后,通过实验采集镜片缺陷图像,并构建数据集进行对比实验。实验结果表明:识别和定位镜片的缺陷的准确率为96.3%,单幅检测时间为24.9 ms。

基于体外光学质量测试设备的非球面人工晶状体光学性能评价

目的应用体外光学质量测试设备OptiSpheric IOL R&D比较2种具有相同负球差值的非球面人工晶状体(IOL)AcrySof IQ SN60WF和Proming A1-UV的光学性能。方法应用OptiSpheric IOL R&D设备,分别在球差为0μm(ISO-1)和+0.28μm(ISO-2)的模型角膜以及孔径为3.0和4.5 mm条件下对+20.0 D蓝光滤过型SN60WF和高次非球面设计的非蓝光滤过全像差补偿型A1-UV IOL进行光学性能评估。分别测量IOL居中,偏心0.3、0.5、0.7、0.9和1.1 mm,倾斜3°、5°、7°、9°和11°的调制传递函数(MTF)以及USAF 1951分辨率测试图。采用紫外可见分光光度计UV-3300测试IOL的光谱透射比。结果与A1-UV IOL相比,SN60WF对400~500 nm波长蓝光的光谱透射比明显降低,能明显减少蓝光透过。当孔径为3.0 mm时,居中位置的SN60WF和A1-UV在100 lp/mm空间频率时ISO-1角膜测量条件下MTF值分别为0.576和0.598,ISO-2角膜测量条件下MTF值分别为0.564和0.563;当孔径为4.5 mm时,ISO-1角膜测量条件下MTF值分别为0.238和0.404,ISO-2角膜测量条件下MTF值分别为0.438和0.339。在3.0 mm孔径下,100 lp/mm空间频率时ISO-1角膜测量条件下MTF值均较ISO-2角膜测量条件下升高;在ISO-1角膜测量条件下,A1-UV相比于SN60WF展现出更优越的光学质量,而在ISO-2角膜测量条件下,2种IOL的光学质量相似。在3.0 mm孔径下,偏心0.3 mm的SN60WF和A1-UV在100 lp/mm空间频率时ISO-1角膜测量条件下MTF值分别为0.414和0.571,ISO-2角膜测量条件下MTF值分别为0.438和0.512,倾斜3°的ISO-1角膜测量条件下MTF值分别为0.522和0.597,ISO-2角膜测量条件下MTF值分别为0.532和0.531,A1-UV在2种角膜测量条件下的MTF值和USAF分辨率测试图未发生显著改变。当IOL发生相同程度偏心或倾斜时,除4.5 mm孔径ISO-1角膜测量条件以外,A1-UV各空间频率的MTF值相较于SN60WF均下降。随着孔径的增大,IOL偏心或倾斜对MTF值和USAF分辨率测试图的影响更加显著。结论SN60WF IOL能有效滤过波长在400~500 nm范围内的蓝光。当2种IOL发生大于0.3 mm的偏心或大于3°的倾斜时,均会造成IOL的光学质量下降。A1-UV相较于SN60WF在体外抗偏心和倾斜性能方面具有一定优势。

双眼不同人工晶状体混搭植入矫正老视的临床效果评价

近年来,功能性人工晶状体(IOL)的应用为白内障患者视觉质量的改善提供了有效选择,术后满意度及脱镜率高,但也存在眩光、立体视损害等不良现象。匹配应用两种不同的IOL进行植入,发挥IOL各自的优点以提供更卓越的术后效果已被越来越多的眼科医师重视,探索更优化的IOL植入方案是治疗白内障同时矫治老视的重要课题。本文就IOL混搭植入在治疗白内障同时矫正老视的研究进展进行综述。

角膜塑形镜在近视防控中的应用进展

近视已经成为严重危害我国青少年眼健康的公共卫生问题,目前,其防控手段主要以药物与光学矫正为主。随着角膜塑形镜在防控近视进展中的推广应用,其受到了广泛关注。本文总结近年来角膜塑形镜在近视防控中的研究进展,发现其干预青少年近视与多种机制相关,如生物力学、视网膜周边离焦、脉络膜效应、眼调节能力等。角膜塑形镜可以有效改善近视青少年的视力与视觉功能,其疗效与年龄、佩戴周期长短等因素存在一定相关性。此外,佩戴过程中存在并发症风险,但在现代数字化技术的加持下,新一代产品“数字化角膜塑形镜”更凸显个性化定制的优势,可以有效提高配镜的准确度与适配度。相信在未来的发展中,角膜塑形镜在全数字化技术的加持下会更加安全、精准。

角膜塑形镜对不同类型近视性屈光参差儿童控制效果

目的 探究角膜塑形镜对不同类型近视性患儿屈光参差的控制效果。方法 纳入2020年9月至2022年11月于长治医学院附属和平医院眼科验配角膜塑形镜并且资料完整的8~16岁近视患儿99例。分为单纯近视性屈光参差组(单眼近视,双眼屈光度差值≥1.00 D)39例和复合近视性屈光参差组(双眼近视,双眼屈光度差值≥1.00D)60例。将两组中双眼间屈光参差量较高(双眼屈光度差值≥2.50 D)的患儿设为高屈光参差亚组(分别为18例和29例),较低(1.00 D≤双眼屈光度差值<2.50 D)的设为低屈光参差亚组(分别为21例和31例)。各组内将屈光度数较高眼设为高度数眼,对侧屈光度数较低眼设为低度数眼。检查并记录两组患儿屈光度、角膜地形图、眼压、角膜内皮、眼轴长度等。比较两组患儿在配戴角膜塑形镜前及戴镜1年后双眼眼轴长度的变化,分析屈光参差程度与双眼眼轴长度变化的相关关系。结果 配戴角膜塑形镜1年后,两组患儿双眼眼轴长度均增长,且均表现为高度数眼的眼轴长度增长量低于低度数眼;在戴镜前及戴镜1年后,两组患儿高度数眼眼轴长度均大于低度数眼,差异均有统计学意义(均为P<0.05)。两组患儿均表现为戴镜1年后双眼间眼轴长度差值缩小;在戴镜前及戴镜1年后,单纯近视性屈光参差组患儿双眼间眼轴长度差值较复合近视性屈光参差组均更大,差异均有统计学意义(t=4.903、2.670,均为P<0.05)。单纯近视性高屈光参差亚组患儿与单纯近视性低屈光参差亚组患儿戴镜前后双眼眼轴长度差值变化量均分别大于复合近视性高屈光参差亚组与复合近视性低屈光参差亚组,差异均有统计学意义(均为P<0.05)。单纯近视性屈光参差组与复合近视性屈光参差组中,屈光参差程度与戴镜前后1年双眼间眼轴长度变化量均呈正相关(r=0.423、0.510,均为P<0.05)。结论 角膜塑形镜可有效减少近视性屈光参差患儿双眼眼轴长度的差异,且对于单纯近视性患儿屈光参差的控制效果优于复合近视性屈光参差患儿。

配戴角膜塑形镜后反转弧区高度差与近视进展的相关性分析

目的探讨配戴角膜塑形镜后反转弧区的高度差(AHDCAP)与眼轴间的关系,分析其与近视进展的相关性。方法收集2018-01至2020-01在山西爱尔眼科医院诊断为近视配戴角膜塑形镜300例患儿的右眼资料(300眼)进行回顾性研究,按照年龄将患者分成8~9岁、10~12岁、13~15岁三组;根据等效球镜分为-1.00 D~-2.00 D组、-2.25 D~-4.00 D组、-4.25 D~-6.00 D组,分析不同年龄组、不同近视度数配戴角膜塑形镜后眼轴增长情况及配戴角膜塑形镜后AHDCAP与眼轴的关系。结果不同年龄组儿童的眼轴增长量分别是0.31(0.20,0.43)mm、0.18(0.07,0.30)mm和0.12(0.04,0.24)mm组之间比较有统计学差异(χ^(2)=48.36,P<0.001)。不同近视组配戴角膜塑形镜1年后眼轴增长量分别为0.32(0.15,0.43)mm、0.24(0.11,0.32)mm和0.13(0.04,0.23)mm,三组之间比较有统计学差异(χ^(2)=36.95,P<0.001)。不同近视组配戴角膜塑形镜1年后AHDCAP值分别为12.25(8.25,17.75)μm、12.88(10.69,19.38)μm和20.75(13.94,24.09)μm,三组之间比较有统计学差异(χ^(2)=57.50,P<0.001)。AHDCAP与等效球镜呈负相关(r=-0.394,P<0.001),AHDCAP与眼轴增长亦呈负相关(r=-0.829,P<0.001)。结论配戴角膜塑形镜后AHDCAP越小,眼轴增长越快,近视发展越快;反之AHDCAP越大,眼轴增长越慢,近视控制越好。增加AHDCAP有利于控制近视儿童的眼轴增长。

小角度间歇性外斜视伴近视患者使用不同类型镜片控制近视及斜视的作用

目的:比较小角度间歇性外斜视伴近视患者使用多点近视离焦镜片、角膜塑形镜、单光镜片的临床有效性。方法:回顾性研究。选取2021-06/2022-09在我院就诊的小角度间歇性外斜视伴近视患者150例(均取主导眼数据进行分析,其中三棱镜检查为双眼所测数据),年龄8-15岁,斜视度-10^(△)--20^(△)(块镜),等效球镜度(SE)为-1.00--5.50 D,按照自愿原则分为三组:HAL组50例配戴多点近视离焦镜片;OK镜组50例夜间配戴角膜塑形镜;SVL组50例配戴普通单光镜片。比较三组患者戴镜前及戴镜1 a的眼轴、裸眼及戴镜棱镜度(取33 cm处三棱镜)、近水平正融像性集合(模糊点)、近立体视变化,采用纽卡斯尔(NCS)评分标准评估三组患者的眼位控制能力。结果:HAL组、OK镜组、SVL组戴镜前眼轴分别为24.83±0.91、24.93±0.97、24.98±0.68 mm(P>0.05),戴镜1 a为25.02±0.90、25.18±0.97、25.45±0.65(P<0.05),与SVL组戴镜1 a眼轴增加0.47±0.30 mm相比,HAL组和OK镜组眼轴分别增加0.19±0.06、0.25±0.21 mm(均P<0.05);戴镜前33 cm处HAL组、OK镜组、SVL组三棱镜检查斜视度分别为-15.00^(△)±3.12^(△)、-14.34^(△)±3.00^(△)、-14.06^(△)±3.22^(△),戴镜1 a戴镜测三组棱镜度分别为:-9.34^(△)±3.84^(△)、-18.42^(△)±4.41^(△)、-19.58^(△)±5.21^(△),与戴镜前相比分别增加了5.66^(△)±2.13^(△)、-4.08^(△)±3.34^(△)、-5.52^(△)±3.70^(△)(P<0.05);戴镜前HAL组、OK镜组、SVL组近立体视分别为89.20″±54.65″、93.00″±52.54″、88.40″±55.31″(P>0.05),戴镜1 a分别为76.00″±20.40″、81.20″±18.91″、100.60″±51.41″(P<0.05);戴镜前三组近水平正融像性集合(模糊点)分别为:15.04±1.97、15.14±1.67、14.62±1.47(P>0.05),戴镜1 a为17.10±2.02、13.12±1.41、13.26±2.45(P<0.05);戴镜1 a HAL组眼位控制能力较OK镜组和SVL组明显增强(P<0.05)。结论:小角度间歇性外斜视伴近视患者配戴HAL组与OK镜组、SVL组相比,可有效控制斜视度及眼轴的变化,尤其对戴镜后斜视度有较好的控制效果,而戴OK镜与SVL均出现外斜视漂移,且HAL组戴镜后立体视觉及正融性集合得到明显改善。

Classical Cosmology II. The Einstein Ring

The Einstein ring is usually explained in the framework of the gravitational lens. Conversely here we apply the framework of the expansion of a superbubble (SB) in order to explain the spherical appearance of the ring. Two classical equations of motion for SBs are derived in the presence of a linear and a trigonometric decrease for density. A relativistic equation of motion with an inverse square dependence for the density is derived. The angular distance, adopting the minimax approximation, is derived for three relativistic cosmologies: the standard, the flat and the wCDM. We derive the relation between redshift and Euclidean distance, which allows fixing the radius of the Einstein ring. The details of the ring are explained by a simple version of the theory of images.