普通用户电子设备使用距离的特征分析

目的：分析普通用户使用电子设备/电脑的工作距离(WD)及移动电话使用距离(MPUD)的特征。

方法：横向描述性研究。经过筛选后，纳入每天使用电子设备/电脑超过2h的专业人员100例，年龄20-62(平均41.2)岁，测量每位受试者工作环境中使用电子设备/电脑的工作距离(WD)、手臂长度和MPUD。

结果：纳入受检者WD明显长于MPUD(61.22±12.35 vs 32.22±6.35 cm； P<0.001)，MPUD明显短于臂长(74.44±4.65 cm； P<0.001)。4%和91%的受检者WD和MPUD分别小于或等于40 cm。WD与MPUD、手臂长度均呈弱相关性(r=0.387，P<0.001； r=0.260，P<0.001)。不同职业受试者WD有显著差异(P=0.021)，军队人员相比大学研究人员和讲师的WD更长(P=0.025)。

结论：普通用户使用电子设备/电脑的工作距离与移动电话使用距离差别较大，移动电话使用距离较近，这对于矫正老视具有一定的参考意义。     

阅读界面和方式对调节反应的影响研究

目的：：比较电脑阅读、手机阅读、纸张阅读条件下,调节反应的差异。探讨不同阅读界面、阅读距离以及亮度对调节反应的综合影响。方法：设置电脑、手机和纸张阅读界面,选取30位青年志愿者,分别在电脑(电脑提供两种不同亮度)、手机以及纸张状态下,使用Grand Seiko WAM 5500红外自动验光仪测调节反应以及瞳孔大小。用SPSS17.0将结果进行方差分析,比较不同阅读条件对人眼调节的影响。结果：电脑屏幕正常亮度下的调节滞后为0.52±0.24D,纸张视标下调节滞后为0.73±0.28D,手机视标下调节滞后为0.72±0.29D。电脑正常亮度屏幕下的调节滞后显著小于手机和纸张视标下的调节滞后量,且均有统计学差异(P<0.05),而手机和纸张视标下调节滞后量无统计学差异。手机阅读引起人眼的调节微波动和瞳孔波动略大于电脑屏幕和纸张,但结果无统计学差异。结论：人眼在阅读电脑屏幕时调节滞后显著小于手机和纸张,后二者则没有显著区别。电脑屏幕亮度在一定程度内的变化并不影响调节反应。     

Objective quantification of viewing behaviours during printed and electronic tasks in emmetropic and myopic ultra-Orthodox Jewish men

Purpose

Ultra-Orthodox Jewish men are known to have a high prevalence of myopia, which may be due to intense near-work from an early age. This study objectively assessed near-viewing behaviours in ultra-Orthodox and non-ultra-Orthodox men in Israel for different tasks.

Methods

Ultra-Orthodox (n = 30) and non-ultra-Orthodox (n = 38) men aged 18–33 years participated. Autorefraction, visual acuity, height and Harmon distance were measured. An objective range-finding sensor was mounted on their spectacles while they performed four 10-min tasks in a randomised order: (1) reading printed material, (2) writing printed material, (3) passive electronic and (4) active electronic tasks. Near-viewing distance and the number of viewing breaks were calculated for each task. Statistical analyses included Student t-tests and the Mann–Whitney test between groups and repeated measures ANOVA or Friedman between tasks.

Results

For all tasks combined, a significantly shorter viewing distance was observed for the ultra-Orthodox group (36.2 ± 7.0 cm) than for the non-ultra-Orthodox group (39.6 ± 6.7 cm, p < 0.05). Viewing distances for the passive reading and electronic tasks were shorter for the ultra-Orthodox group (36.9 ± 7.7 cm vs. 41.3 ± 8.1 cm, p < 0.03 and 39.0 ± 10.1 vs. 43.9 ± 9.3, p < 0.05, respectively). Viewing distances were significantly different between all four tasks, with writing having the closest distance. No correlation was found between working distance and spherical equivalent or Harmon distance. However, a significant correlation was found in the ultra-Orthodox group between working distance and height for each task (p < 0.04, R < 0.42 for all). There was no difference in the number of viewing breaks between the groups.

Conclusion

When reading a book and viewing an iPad, ultra-Orthodox men demonstrated a closer objective working distance than non-ultra-Orthodox men. This shorter viewing distance may contribute to the high prevalence and degree of myopia in this population.     

不同角膜仪测量的角膜曲率值的一致性分析

目的：比较测得后三种不同角膜仪测量的角膜曲率,以评估其测量值之间的一致性。

方法：前瞻性研究。252例患者(252眼)使用IOL Master(IM),Bausch & Lomb手动角膜仪(Man)以及TOPCON KR-8800自动角膜仪(Top)进行角膜曲率测量。记录并对比平均角膜曲率值。使用Bland Altman统计方法进行仪器间的一致性分析。

结果：1)IOL Master 和 手动角膜仪：IOL Master平均角膜曲率为44.62±1.52 D,手动角膜仪为44.60±1.52 D。 t-test显示差异具有统计学意义(P=0.001); Bland-Altman图显示两种仪器间95%一致性区间(LOAs)为-0.22～0.22; 2)IOL Master 和自动角膜仪：IOL Master平均角膜曲率为44.62±1.52 D,自动角膜仪为44.46±1.53 D。t-test显示差异具有统计学意义(P<0.0001)。Bland-Altman图显示两种仪器间95%LOAs为 -0.24～0.55; 3)自动角膜仪和手动角膜仪：自动角膜仪平均角膜曲率为44.60±1.52 D,手动角膜仪为44.46±1.53 D。t-test显示差异具有统计学意义(P<0.0001)。Bland-Altman图显示两种仪器间95%LOAs为-0.30～0.57。

结论：使用不同的仪器获得的角膜曲率数据是不可替换的,这对于白内障外科医生在外科手术计划和结果评估方面具有重要意义。     

Late in-the-bag spontaneous IOL dislocation: risk factors and surgical outcomes

AIM: To evaluate the possible predisposing risk factors for late in-the-bag spontaneous IOL dislocations and to study the early surgical and visual outcomes of repositioning and exchange surgeries. METHODS: Medical and surgical records of 39 eyes of 39 patients who underwent IOL repositioning or exchange surgery for dislocation between 2010 and 2018 were reviewed. Possible predisposing risk factors and some characteristics of late in-the-bag spontaneous IOL dislocations; outcomes of IOL repositioning and exchange surgeries, including visual acuity, refractive status before and after surgery and postoperative complications were evaluated. RESULTS: The predisposing factors for late in-the-bag spontaneous IOL dislocations were pseudoexfoliation [PEX; 12/39 (30.8%)], previous vitreoretinal surgery [7/39 (17.9%)], axial myopia [3/39 (7.7%)], both PEX and axial myopia [1/39 (2.6%)], both previous vitreoretinal surgery and axial myopia [2/39 (5.1%)] and uveitis [1/39 (2.6%)]. The mean interval between cataract and dislocation surgery was 7.23y, greater in PEX positive group (8.63y). The mean best corrected visual acuity (BCVA) improved significantly after dislocation surgery (P<0.001) and also improved significantly after exchange surgery (P=0.001). The mean value of spherical equivalant decreased significantly after dislocation surgery (P=0.011), whereas corneal astigmatism increased but this difference was not significant after dislocation surgery and exchange surgery (P=0.191, P=0.074, respectively). CONCLUSION: The most prevelant risk factors for late in-the-bag spontaneous IOL dislocations are PEX, previous vitreoretinal surgery and axial myopia. In the management of IOL dislocations, exchange surgery with small corneal incision seemed effective with improved BCVA and safety with low postoperative complications.     

Corneal white-to-white distance and mesopic pupil diameter

AIM: To study the relationship between corneal white-to-white (WTW) distance and mesopic pupil diameter. METHODS: This study is composed of 30 cases that underwent photorefractive keratotomy (PRK). Pupil size measurements were performed with Schwind ORK wavefront analyzer in mesopic conditions. WTW distance was measured with a measuring caliper. Also, A-scan ultrasound examination was performed in all patients. The relationship among the mesopic pupil diameter and age, sex, axial length, lens thickness, anterior chamber depth(ACD), horizontal WTW distance, vertical WTW distance, spherical equivalent, and average keratometry were analyzed with univariate and multivariate regression analysis. RESULTS: Mean pupil diameter was (6.39±0.80)mm (range: 3.70mm-7.73mm). Horizontal WTW distance measurements were between 11.00mm and 12.50mm and mean horizontal WTW distance was (11.79±0.43)mm. On the other hand, vertical WTW distances ranged between 10.00mm and 13.00mm, and their mean was (11.42±0.72)mm. Bivariate correlation between pupil diameter and other variables showed that the axial length, ACD, spherical equivalent, and horizontal WTW distance had a moderate correlation with mesopic pupil diameter. Multiple regression analysis revealed that spherical equivalent and horizontal WTW distances were significantly associated with mesopic pupil diameter (R=0.598, R²=0.358 P=0.02). CONCLUSION: This study shows that mesopic pupil diameter is closely related to horizontal WTW distance. These two factors must be taken in consideration together in preoperative ablation zone planning.     

Performance of three biometry devices in patients with different grades of age‐related cataract

Purpose: The new Lenstar biometry device was compared in a typical clinical setting to the IOL‐Master and Visante‐OCT. Methods: Fifty‐one eyes of 51 patients with age‐related cataract were examined with Lenstar LS900 (Haag Streit AG) biometer, IOL‐Master V.5 (Carl Zeiss Meditec AG) and Visante‐OCT (Carl Zeiss Meditec AG) before cataract surgery. Central corneal thickness (CCT), anterior chamber depth (ACD), keratometry readings of flattest and steepest meridian (K), corneal radius (R) and axial length (AL) values were correlated. Cataracts were graded according to the Lens Opacities Classification System III (LOCS) regarding nuclear colour (NC), nuclear opalescence (NO), cortical (C) and posterior subcapsular (P) cataract. Results: Mean values and standard deviations for AL, K and R was 23.66 ± 1.23 mm and 23.67 ± 1.26 mm, 43.24 ± 1.69 dpt and 43.16 ± 1.71 dpt, 7.68 ± 0.29 mm and 7.70 ± 0.28 mm with the IOL‐Master and with the LS900, respectively (r = 0.99 and p = 0.76, r = 0.99 and p = 0.029, r = 0.89 and p = 0.14, respectively). Visante‐OCT demonstrated highest values of three devices regarding to ACD followed by Lenstar LS900 and IOLMaster. Axial length measurements were unfeasible in 10% of the cases (five patients) and this significantly correlated with the presence of posterior subcapsular cataract of LOCS III grade 4.0 or higher. Conclusions: IOL‐Master, Lenstar LS900 and AC–OCT proved to be excellent non‐contact measurement methods in eyes with age‐related cataract. Nevertheless, ultrasound biometry is still required for cases with dense posterior subcapsular cataract.     

A超和IOL Master测量人工晶状体度数的差异性研究

目的：比较A超和IOL Master在人工晶状体度数测量方面的差异性。
　　方法：选取226例230眼年龄相关性白内障患者,术前分别采用A超和IOL Master测量眼轴长度、自动验光仪测量角膜曲率,使用SRK-T公式计算需要植入的人工晶状体度数,术后3 mo使用自动验光仪测量角膜曲率,用综合验光仪检查患者屈光状态并分析。
　　结果：所有患眼使用A超和IOL Master测得的平均眼轴长度分别为23.48±1.94、23.75±1.96mm,两组数据对比差异有统计学意义(P<0.05);随机分组后A超组术前平均角膜曲率为43.94±1.81D,术后为43.98±1.87D,两者比较差异无统计学意义(P>0.05),IOL Master组术前平均角膜曲率为44.10±1.57D,术后为44.11±1.58D,两者比较差异无统计学意义( P>0.05);A 超组和 IOL Master 组术后的平均绝对屈光误差( mean absolute refractive error,MAE)分别为0.47±0.27、0.41±0.19D,两组比较差异有统计学意义(P<0.05)。
　　结论：IOL Master在人工晶状体度数测量中略优于A超测量。     

Accuracy of intraocular lens power calculations in eyes with axial length <22.00 mm

Background: To assess the accuracy of Haigis, Holladay 1, Hoffer Q and SRK/T formulae in eyes with axial length of <22.00 mm. Design: Retrospective comparative analysis. Participants: 163 eyes of 97 patients undergoing phacoemulsification and intraocular lens (IOL) implantation. Methods: Ocular biometry was performed using IOLMaster laser interferometry. Predicted refractive outcomes before and after lens constant adjustment were compared to actual refractive outcomes. Main Outcome Measures: Mean prediction (ME) and mean absolute errors (MAE) with standard deviations (±SD). Results: Mean preoperative spherical equivalent was +5.44D ± 1.97D. Mean axial length was 21.20 mm ± 0.60 mm. Using standard IOL constants the MAE for Hoffer Q (0.62D, ±0.52D) and Holladay 1 (0.66D ± 0.52D) were significantly lower than SRK/T (MAE 0.91D ± 0.64D; P = <0.0005 and P = 0.001 respectively), but not Haigis (MAE 0.82D ± 0.83D, P = 0.071 and 0.22 respectively). MAEs for all formulae were significantly reduced by IOL constant adjustment (all P = <0.001). Following this there was no statistically significant difference in MAEs between formulae (range 0.50–0.57D, P = 0.57). Increasing MAE was significantly associated with reducing axial length and increasing IOL power for all formulae. For bilateral cases, prediction errors between eyes were significantly correlated across all formulae (all P = <0.0001) and explained 32–42% of the variance in prediction error between eyes. Conclusions: Prediction of postoperative refraction in patients with short axial lengths is challenging and at the limit of current, popular IOL formulae. There is now a clear need for prospective studies to assess latest generation IOL formulae such as Holladay 2 or Olsen in small eyes.     

Pentacam与IOL Master测量角膜屈光力的比较

目的：比较Scheimpflug 原理摄像系统Pentacam与光学相干生物测量仪IOL Master测量角膜正常的白内障患者角膜屈光力,分析两者的一致性。

方法：前瞻性临床研究。选取我院2017-01/06门诊就诊的角膜正常的白内障患者41例64眼,术前分别采用IOL Master和Pentacam测量角膜屈光力,采集的数据包括：sim K、true net power、角膜中央1.0～7.0mm直径Holladay equivalent K(EKR)(Pentacam)及Km\〖Km=(K1+K2)/2\〗(IOL Master)。两种仪器测量K值之间的差异采用配对样本t检验,其相关性采用Pearson相关性分析,一致性采用Bland-Altman法。

结果：角膜正常的白内障患者Pentacam测量所得true net power、角膜中央1.0、2.0、3.0mm直径EKR 比IOL Master测量所得Km小; 角膜中央4.5、5.0、6.0、7.0mm直径EKR比IOL Master 测量所得Km大,差异具有统计学意义(均P<0.01)。Pentacam测量所得 sim K、角膜中央4.0mm直径EKR与IOL Master测量所得Km差值最小,差值均值分别为-0.03±0.252和0.04±0.244D,差异无统计学意义(t=-1.018,P=0.313; t=1.461,P=0.149); 且一致性最高,95%一致性界限分别为-0.53～0.46D和-0.43～0.52D。两种仪器间所测量K值均具有较高的相关性(均r>0.9,P<0.01)。

结论：角膜正常的白内障患者Pentacam测量所得sim K、角膜中央4.0mm 直径EKR与IOL Master测量所得Km一致性最高,但使用中需结合临床意义进一步对仪器的适用范围加以判断。     

小学生双眼屈光不均衡发育的影响因素分析

目的：研究6～12岁儿童双眼屈光不均衡发育的影响因素。

方法：于2019-12在天津市滨海新区两所小学采用整群抽样的方法选取儿童607人,平均年龄8.2±1.8岁,均进行光学生物测量(眼轴长度、角膜前表面平均屈光力)、睫状肌麻痹后屈光检查及问卷调查。

结果：纳入儿童等效球镜度为-0.11±1.63D,双眼等效球镜度差异为-0.08±0.64D,等效球镜度差异绝对值为0.41±0.49D。检出屈光参差儿童56人,非屈光参差儿童551人,屈光参差儿童和非屈光参差儿童双眼角膜屈光力差异绝对值无差异(0.30±0.34D vs 0.27±0.24D,P=0.430),眼轴差异绝对值有差异(0.67±0.39mm vs 0.13±0.13mm,P=0.005)。多因素线性回归分析显示,每周手机/电脑使用时间、每周近距离工作时间、每周视疲劳次数、习惯阅读距离是屈光不均衡发育程度(双眼等效球镜度差异绝对值)的影响因素; 习惯阅读距离、写字时利手是屈光不均衡发育偏向(双眼等效球镜度差异)的影响因素。

结论：6～12岁儿童看手机/电脑时间长、近距离工作时间长、视疲劳次数增多、习惯阅读距离近可能引起屈光发育不均衡程度增加,写字时右利手且头部严重左偏和右偏的儿童右眼近视程度较左眼更深。     

北京市羊坊店学区两个年级组小学生AL/CR分布情况的分析

目的:比较眼轴长度与角膜曲率半径比值(AL/CR)>3的人数在不同人群中所占比例的差异,探寻近视防治的监控点。方法:选择北京市羊坊店学区全部小学的一年级、四年级学生2970例。采用标准对数视力表测量远视力(DVA),光学相干生物测量仪(IOL Master)测量眼轴长度(AL)及角膜曲率半径(CR)。取有眼测量值统计分析。结果:一年级组1 282例,年龄6.44±0.52岁;四年级组1688例,年龄9.25±0.46岁。一年级组与四年级组相比,AL明显较短(P=0.000);DVA明显较好(P=0.000);AL/CR明显较小(P=0.000);角膜曲率半径值(CR)无显著性差异(P=0.31)。男性与女性相比,AL明显较长(P=0.000);DVA较好(P=0.01);AL/CR明显较大(P=0.000);CR明显较长(P=0.000)。四年级组AL/CR>3人数的比例显著高于一年级组(x~2=644.929,P=0.000)。高龄组中AL/CR>3人数的比例显著高于低龄组(x~2=644.807,P=0.000)。随着远视力的下降,一年级组与四年级组中AL/CR>3人数的比例均显著增高(x~2=82.914,x~2=297.236;P=0.000)。结论:不同学龄组小学生眼球生物学参数的对比分析表明学龄的延长影响学生的视力和眼轴发育。随着年龄的增长和远视力的下降,存在近视患病危险因素的人数比例增加,群体中近视患病的危险性也相应增加。在对大规模样本进行的眼科研究活动中,应用IOL Master测量眼球的生物学参数具有显著优势。     

Spherical aberration, visual performance and pseudoaccommodation of eyes implanted with different aspheric intraocular lens

Purpose: To compare spherical aberration, visual performance and pseudoaccommodation in pseudophakic eyes implanted with aspheric intraocular lenses (IOLs) of Tecnis Z9001 with negative spherical aberration (AMO Inc.), aspheric aberration‐free IOLs of Akreos AO (Bausch & Lomb Inc.) and spherical IOLs of KS‐1 (Cannon Staar Inc.). Methods: A total of 196 patients presenting for cataract surgery were randomly assigned to receive one of three types of IOLs in one eye. Spherical aberration, best‐corrected far visual acuity (BCFVA), distance corrected near visual acuity (DCNVA), contrast sensitivity, glare sensitivity and pseudoaccommodation were measured and compared 3 months postoperatively. Results: At 3 months postoperatively, the mean spherical aberration Z(4,0) for 5 mm pupil size in eyes with Tecnis Z9001 IOLs, Akreos AO IOLs, and KS‐1 IOLs were 0.022 ± 0.071 µm, 0.141 ± 0.070 µm and 0.210 ± 0.108 µm, respectively (P < 0.001), and significant difference was also found in two aspheric IOLs (P < 0.001). Compared with spherical KS‐1 IOLs, Tecnis Z9001 IOLs significantly improved the contrast sensitivity at 4.0°, 2.5° visual angle and glare sensitivity at 4.0°, 2.5°, 2.0°, 1.6° visual angle, Akreos AO IOLs significantly improved contrast sensitivity at 2.5° and glare sensitivity at 4.0°, 2.5°, 2.0°, but no difference statistically significance were found between two aspheric IOLs at any visual angle. In addition, there was no significant difference among three IOLs regarding BCFVA, DCNVA and pseudoaccommodation. Conclusions: All the studied IOLs can provide good visual acuity. Compared with spherical IOLs, both aspheric IOLs can significantly decrease spherical aberration and improve visual performance without the reduction of pseudoaccommodation amplitude.     

The repeatability of MNREAD acuity charts and variability at different test distances.

PURPOSE: The purposes of this study are to establish the repeatability of the MNREAD acuity charts in a normal adult population and to determine the coefficient of repeatability for reading acuity, reading speed, and critical print size. The study also investigates how changing the working distance affects these parameters. METHODS: Thirty normal young adults (mean age, 23.3 years) participated. Test-retest repeatability was assessed at 40 cm over two sessions by the same examiner using MNREAD charts 1 and 2. Additional measurements were also carried out at 24 cm and 52 cm working distances. The distance and the version of the chart used were randomized. RESULTS: The coefficient of repeatability was found to be +/- 0.05 logarithm of the minimum angle of resolution (logMAR) for reading acuity, +/- 0.12 logMAR for critical print size, and +/- 8.6 words per minute for reading speed. Reading acuity and critical print size changed significantly with testing distance (p = 0.001). No changes were found in the reading speed at the different test distances (p = 0.27). CONCLUSIONS: The MNREAD acuity charts can be used reliably to measure reading acuity, reading speed, and critical print size in a normal adult population.     

Comparing the corneal curvatures obtained from three different keratometers-IOL Master, Bausch & Lomb Manual keratometer and TOPCON KR 8800 autokeratometer

AIM: To compare the corneal curvature and to investigate the agreement between three different keratometers. METHODS: In this prospective study, keratometry was performed using an IOL Master, a Bausch & Lomb manual keratometer and TOPCON KR-8800 autokeratometer on 252 eyes of patients recruited from camps for cataract surgery. The average keratometry values were recorded and compared. The agreements between the instruments were analyzed using the Bland Altman statistical method. The main outcome measure was average keratometry values. RESULTS: The mean corneal power was 44.62±1.52 D with the IOL Master, 44.60±1.52 D with the manual keratometer, and 44.46±1.53 D with the autokeratometer. The paired ttest demonstrated a statistically significant difference in the mean corneal power between the IOL Master and manual keratometer (P=0.001), IOL Master and autokeratometer (P<0.0001), autokeratometer and manual keratometer (P<0.0001). The 95% limits of agreement (LoA) of the IOL Master and manual keratometer were -0.22 to 0.26; IOL Master and autokeratometer were -0.24 to 0.55; autokeratometer and manual keratometer were -0.30 to 0.57 as shown in the Bland-Altman plot. CONCLUSION: Keratometry data obtained with different instruments may not be interchangeable, a fact that has important implications for cataract surgeons with respect to both surgical planning and outcomes auditing.     

虹膜纹理引导的飞秒激光囊膜标记法在Toric IOL植入中的应用

目的:对比飞秒激光囊膜标记(FLACM)法与裂隙灯下手工标记(SAMM)法的Toric IOL轴位准确性和术后效果。方法:将拟行白内障超声乳化联合Toric IOL植入术的患者分为两组,分别采用FLACM法(25例25眼,FLACM组)与SAMM法(25例25眼,SAMM组)对散光轴位进行标记。评估比较术后两组患者裸眼远视力(UCDVA)、最佳矫正远视力(BCDVA)、残余散光(RA)、IOL轴位偏离度、总调制传递函数(MTF Total)。结果:术后1mo,FLACM组UCDVA(LogMAR)显著优于SAMM组(0.15±0.09 vs 0.22±0.11,P<0.05);FLACM组术后RA和IOL轴位偏离度均显著低于SAMM组(0.30±0.18D vs 0.64±0.28D,P<0.05;3.64°±1.68°vs 5.40°±3.44°,P<0.05);两组BCDVA和MTF Total均无差异(P>0.05)。术后UCDVA(LogMAR)与RA(r=0.350,P<0.05)、IOL轴位偏离度(r=0.369,P<0.05)呈正相关,与MTF Total值呈负相关(r=-0.290,P<0.05);术后RA与IOL旋转度呈正相关(r=0.431,P<0.05)。结论:FLACM法标记的Toric IOL轴位比SAMM法更加精确,从而获得更好的散光矫正效果和术后视力。     

两种白内障手术联合Toric IOL植入术在长眼轴患者中的应用

目的：观察飞秒激光辅助白内障手术(FLACS)与传统白内障手术(Phaco)联合Toric IOL植入术在眼轴大于24mm的患者中的应用疗效。

方法：前瞻性研究。选取2017-01/2018-03在我院行手术治疗的白内障患者49例49眼,飞秒组行FLACS术联合Toric IOL植入术,传统组行Phaco术联合Toric IOL植入术。观察两组患者视力、散光度、斯特列尔比(strchl)、高阶像差情况。

结果：术后3mo,飞秒组和传统组患者视力(0.092±0.089和0.131±0.096)均较术前(0.855±0.213和0.948±0.135)显著改善(P<0.05),但两组之间视力、总残余散光、strchl值、角膜和全眼高阶像差均无差异(P>0.05)。飞秒组全眼4mm瞳孔直径下4s3、4s4、4Total和6mm瞳孔直径下6s5与strchl值均呈负相关,传统组全眼4mm瞳孔直径下4s3、4Total和6mm瞳孔直径下6s3、6s3+s5、6Total与strchl值均呈负相关。

结论：眼轴大于24mm的白内障患者植入Toric IOL能有效矫正角膜规则散光,FLACS术和传统超声乳化手术均能使其保持眼内旋转稳定性,显著改善术后视觉质量。     

Clinical outcomes after femtosecond laser assisted cataract surgery with implantation of the TECNIS Symfony intraocular lens

AIM: To evaluate the clinical outcomes in terms of vision across distances (near, intermediate, and far), contrast sensitivity and subjective patient satisfaction after femtosecond laser-assisted cataract surgery (FLACS) with implantation of an extended range of vision (ERV) intraocular lens (IOL). METHODS: Forty patients (55 eyes) undergoing bilateral or monocular FLACS with implantation of the ERV IOL TECNIS Symfony (Johnson & Johnson Vision) were enrolled. Uncorrected distance (UDVA), intermediate (UIVA) and near visual acuities (UNVA) were evaluated at 3mo after surgery, as well the defocus curve, contrast sensitivity, patient satisfaction and spectacle independence. RESULTS: No severe complications occurred. All eyes showed a central position of the IOL in the capsular bag without tilting at 3mo after surgery. 3mo postoperative mean logMAR visual acuity at 5 m, 67 cm and 40 cm were -0.04 ±0.08, -0.17±0.22, 0.37±0.17, respectively. All patients obtained satisfactory UDVA and UIVA, as well as functional UNVA, meeting the needs of daily life. Spectacle independence rate was 94.55%. Contrast sensitivity results did not differ from those obtained with monofocal aspheric lenses. Likewise, no moderate and severe photic phenomena were reported. Mean patient satisfaction scores with distance, intermediate and near vision were 9.0, 9.0, and 7.0, respectively. CONCLUSION: FLACS with implantation of the ERV IOL TECNIS Symfony provides a successful visual restoration at far, intermediate distance and a functional-range near vision acuity, with minimal level of disturbing photic phenomena, and high rates of spectacle independence and patient satisfaction.     

The comparative study of two recently developed A‐scan devices: determination of central corneal thickness,anterior chamber depth and axial length

Purpose: The clinical use and comparison of two recently developed A‐scan ultrasound devices. Methods: The same investigator determined central corneal thickness (CCT), anterior chamber depth (ACD) and axial length (AL) with an OcuScan RxP (Alcon, Forth Worth, Texas, USA) and an AL‐2000 (Tomey, Erlangen, Germany) ultrasound device in 80 eyes of 40 patients. The mean patient age was 63.72 years [standard deviation (SD) 18.92]. The patients did not suffer from any systemic or eye disease affecting the anterior and posterior segments of the eye, and their refractive error (spherical and astigmatic) did not exceed ± 3.0 dioptres. Results: The value of the CCT was 541.55 (SD 34.97) µm with the OcuScan RxP, and 547.46 (SD 35.70) µm with the AL‐2000 device (P < 0.001). With respect to the ACD and AL, significantly lower values were obtained with the AL‐2000 instrument (P < 0.001). The ACD was 2.92 (SD 0.48) mm with the AL‐2000 and 3.07 (SD 0.47) mm with the OcuScan RxP device. The AL was 22.67 (SD 0.84) mm with the AL‐2000 and 22.81 (SD 0.87) mm with the OcuScan RxP instrument. However, a positive and significant correlation could be demonstrated between the devices (r = 0.88 CCT, r = 0.86 ACD and r = 0.91 AL; P < 0.001). Conclusion: The instruments are reliable in clinical use; however, statistically significant differences were found between the devices. During patient follow‐up, the devices cannot simply be used interchangeably.     

Comparison of corneal measurements in keratoconic eyes using rotating Scheimpflug camera and scanning-slit topography

AIM: To compare the anterior segment measurements obtained by rotating Scheimpflug camera (Pentacam) and Scanning-slit topography (Orbscan IIz) in keratoconic eyes. METHODS: A total of 121 patients, 71 males (58.7%) and 50 females (41.3%) (214 eyes) with the diagnosis of keratoconus (KC) were enrolled in this study. Following diagnosis of KC by slit-lamp biomicroscopic examination, central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior chamber depth (ACD), and pupil diameter (PD) were measured by a single examiner using successive instrumentation by Pentacam and Orbscan. RESULTS: There was no significant difference between the two instruments for the measurement of CCT and TCT. In contrast, scanning-slit topography measured ACD (3.46±0.40 mm vs. 3.38±0.33 mm, P=0.019) and PD (4.97±1.26 mm vs 4.08±1.19 mm, P<0.001) significantly larger than rotating Scheimpflug camera. The two devices made similar measurements for CCT (95% CI: -2.94 to 5.06, P=0.602). However, the mean difference for TCT was -6.28 (95% CI: -10.51 to -2.06, P=0.004) showing a thinner measurement by Orbscan than by Pentacam. In terms of the ACD, the mean difference was 0.08 mm (95% CI: 0.04 to 0.12, P<0.001) with Orbscan giving a slightly larger value than Pentacam. Similarly, Orbscan measurement for PD was longer than Pentacam (95% CI: 0.68 to 1.08, P<0.001). CONCLUSION: A good agreement was found between Pentacam and Orbscan concerning CCT measurement while comparing scanning-slit topography and rotating Scheimpflug camera there was an underestimation for TCT and overestimation for ACD and PD.