年龄相关性白内障患者超声乳化手术前后对比敏感度分析

目的研究年龄相关性白内障患者行超声乳化+球面人工晶状体植入术前后对比敏感度的变化。方法选取46～84岁的年龄相关性白内障患者22例(30眼),术前矫正视力为0.5～0.8,行白内障超声乳化+可折叠球面人工晶状体植入术。利用美国Stereo Optec6500视功能测试仪在术前及术后1个月测试患者,分析对比敏感度的变化。用SPSS15.0软件对数据进行统计学分析。结果除了在18.0c·d-1昏暗及昏暗+眩光条件下外,患者术后对比敏感度较术前在低、中、高空间频率均有提高,且与术前的差异均具有统计学意义(均为P<0.01)。明亮条件下,术前眩光对比敏感度在中、低空间频率(1.5c·d-1、3.0c·d-1、6.0c·d-1)低于无眩光状态(均为P<0.01),术后眩光对比敏感度在中、低空间频率高于无眩光状态(均为P<0.01)。昏暗条件下,术前和术后中、低空间频率眩光对比敏感度低于无眩光状态(均为P<0.05)。结论中、低空间频率眩光对比敏感度检查较传统视力检查能更有效评估未熟期年龄相关性白内障患者手术前后的视功能。     

老视眼CK术后早期对比敏感度变化和眩光测试

目的 研究传导性角膜成形术(CK)术后早期远近视力变化、暗视/明视下对比敏感度函数(CSF)变化及眩光刺激对CSF的影响,评估患者术后早期的视觉质量.方法 对24例有老视症状者单眼行CK治疗以改善近视力,其中11例伴轻度远视者另一眼同时手术以提高远视力,并分别于术前及术后1、3、6个月测量2种模拟背景光(暗视/明视)下的CSF和暗视/明视下有眩光刺激下的CSF. 结果 双眼术后各空间频率CSF较术前差异无统计学意义(P＞0.05).双眼明视下手术前后眩光刺激对各空间频率的CSF差异均无统计学意义(P＞0.05),暗视下眩光刺激明显降低了术后3个月的1.5、3、6个月1.5cpd的CSF(P＜0.05).术眼暗视下术后1、3、6个月眩光刺激引起的CSF的降低在低频区(1.5cpd、3cpd),差异有统计学意义(P＜0.05). 结论 CK术后,明视/暗视下各空间频率CSF均无明显变化.眩光刺激对CSF的影响主要集中在暗视下中、低频率.     

AcrySof ReSTOR及Tecnis ZMB00多焦点人工晶状体植入术后视觉质量的比较

目的 比较植入AcrySof ReSTOR及Tecnis ZMB00多焦点人工晶状体(muhifocal intraocular lens,MIOL)术后患者的视觉质量.方法 回顾性病例对照分析2012年1月至2013年6月期间在我院眼科行白内障超声乳化联合MIOL植入术的患者32例(43眼),根据植入的MIOL不同分为两组,分别为植入AcrySof ReSTOR+4 D MIOL的A组,17例(22眼);植入TecnisZMB00 +4 D MIOL的T组,15例(21眼).术后随访3个月,使用标准对数视力表测量裸眼远视力(5 m)及Colenbrander Mixed Contrast视力测试卡测量中距离视力(66 cm)及近视力(40 cm).术后3个月时测量明视、暗视和眩光状态时不同空间频率下的对比敏感度,同时对患者视觉干扰、满意度及脱镜率进行问卷调查.结果 术后3个月,两组间裸眼远视力、中距离视力及近视力差异均无统计学意义(均为P ＞0.05).两组在明视及明视眩光状态时3c·d-1、6c·d-1、12 c·d-1、18 c·d-1空间频率下的对比敏感度差异均无统计学意义(均为P＞0.05);暗视及暗视眩光状态下时,T组在6c·d-1、12 c·d-1、18c·d-1空间频率下对比敏感度要优于A组,差异均有统计学意义(均为P ＜0.05),在低空间频率(3 c·d-1)下两组间差异均无统计学意义(均为P＞0.05).问卷调查示两组患者术后均极少出现影响正常生活的视觉干扰现象,术后满意度差异不明显.结论 AcrySofReSTOR +4 D阶梯渐进衍射型MIOL及Tecnis ZMB00+4 D全光学面衍射型MIOL均能为白内障患者提供满意的全程视力,尽管在暗视及暗视状态下眩光时的高空间频率下Tecnis ZMB00 MIOL对比敏感度要优于AcrySof ReSTOR MIOL,但对于绝大多数患者日常生活质量无明显影响.     

ICL植入术对高度近视眼对比敏感度影响的研究

目的:研究有晶状体眼后房型人工晶状体(ICL)植入术对高度近视眼对比敏感度的影响。方法:选择行ICL植入术的高度近视眼患者27例52眼,用对比敏感度测试仪分别测试术前及术后1wk最佳矫正视力下的对比敏感度值。测试分为明视、明视眩光、暗视、暗视眩光四种模式,每种模式测试1.5,3,6,12,18c/deg五个空间频率。结果采用配对t检验进行统计学分析,以P<0.05表示差异有统计学意义。结果:ICL植入术后1wk裸眼视力4.8558±0.6960,术后1mo裸眼视力4.9519±0.1513,术后3mo裸眼视力4.8865±0.5929。术后1wk;1,3mo裸眼视力较术前裸眼视力均明显提高(P<0.05)。术后明视、暗视、明视眩光、暗视眩光四种模式下空间频率为1.5,3,6,12,18c/deg对比敏感度值较术前均有明显提高(P<0.05)。结论:高度近视眼植入ICL后对比敏感度较术前明显提高,视功能得到显著改善。     

Aurium变色人工晶状体植入术后对比敏感度和眩光对比敏感度的研究

目的 研究Aurium变色人工晶状体对术后对比敏感度和眩光对比敏感度的影响.方法 临床病例系列对比研究.选取2010年8月至2011年4月在南昌大学第二附属医院眼科就诊的白内障超声乳化联合人工晶状体植入术后患者,且随访资料完整的病例70例(眼),其中37例为Aurium (model400)变色人工晶状体组,33例为黄色蓝光滤过型IQ (SN60WF)人工晶状体组.观察患者术后3个月时的裸眼视力(UCVA),最佳矫正视力(BCVA),对比敏感度(CS)和眩光对比敏感度(GS).结果 二组患者术后3个月时的裸眼视力和最佳矫正视力差异均无统计学意义(P＞0.05).Aurium组和IQ组在明适应、明适应眩光、暗适应条件下,两组之间的对比敏感度和眩光对比敏感度差异无统计学意义(P＞0.05),在暗适应眩光条件下Aurium组的眩光对比敏感度(空间频率3 cpd、6 cpd)要优于黄色蓝光滤过型IQ组,差异有统计学意义(P＜0.05).结论 植入Aurium变色人工晶状体术后患者的视力与黄色蓝光滤过型IQ人工晶状体的视力差异无统计学意义.Aurium变色人工晶状体在暗适应眩光条件下,空间频率(3 cpd、6 cpd)的眩光对比敏感度要优于黄色蓝光滤过型IQ人工晶状体.     

孔源性视网膜脱离患者术后对比敏感度

目的 了解视力恢复良好的孔源性视网膜脱离(RRD)术后对比敏感度情况,并进一步分析其与有无累及黄斑的相关性.方法 回顾性病例对照研究.选取50例(50眼)术后最佳矫正视力达到或超过4.9的单纯性RRD患眼,根据术前光学相干断层扫描检查结果分为黄斑脱离组(20眼)和黄斑未脱离组(30眼).另选30例(30眼)作为正常对照组.术后采用CSV- 1000E测定各组在眩光及无眩光状态下的对比敏感度.最佳矫正视力、各空间频率的对比敏感度值比较采用单因素方差分析,两两比较采用LSD t检验.结果 平均随访(12.2±5.3)个月,3组间最佳矫正视力差异无统计学意义(F=2.200,P＞0.05).在有眩光和无眩光状态下,黄斑脱离组和黄斑未脱离组在各个空间频率下都低于正常对照组,差异具有统计学意义(F=12.577～45.438,P均＜0.01).黄斑脱离组和黄斑未脱离组在有眩光18.0 c/d空间频率的对比敏感度分别为0.69±0.33、0.87±0.23,差异有统计学意义(t=2.418,P＜0.05),其余空间频率黄斑脱离组和黄斑未脱离组差异无统计学意义.结论 尽管部分RRD患者视力可以恢复良好,但对比敏感度仍不能恢复至正常人水平.与术前黄斑未脱离者相比,术前黄斑脱离的患者术后有眩光18.0 c/d状态下的对比敏感度较差.     

非球面和球面人工晶状体植入术后远期对比敏感度和眩光敏感度的对比研究

目的 比较年龄相关性白内障患者植入非球面人工晶状体术后远期视力及对比敏感度和眩光敏感度的改变,以评价非球面人工晶状体的有效性和安全性.方法 将120例(161只眼)拟行超声乳化白内障摘除联合人工晶状体植入术的年龄相关性白内障患者随机分为3组,分别植入AerySof IQ非球面人工晶状体(47例54只眼),KS-3Ai预装式非球面人工晶状体(46例52只眼)和AerySof Natural蓝光滤过型球面人工晶状体(42例55只眼),随访时间均超过6个月.观察患者术后最佳矫正远视力、对比敏感度和眩光敏感度以及并发症情况.统计学分析采用方差分析、配对t检验和检验.结果 三组患者术后1周、1个月和≥6个月最佳矫正远视力差异无统计学意义(P=0.874,P=0.243,P=0.160).术后≥6个月,非球面组在夜(1.5c/d、3.0 c/d、6.0 c/d)及夜 周边眩光(1.5e/d、3.0 c/d、6.0 c/d)条件下对比敏感度均优于球面组,差异有统计学意义(P=0.004,P=0.040,P=0.050;P=0.009,P=0.031,P=0.036),非球面组之间差异无统计学意义(P>0.05).结论 植入非球面人工晶状体术后患者视力有较好的趋势,对比敏感度在暗视环境(低、中空间频率)下明显优于传统的球面人工晶状体,能较全面地改善白内障患者术后的视觉质量.     

海军飞行员视觉对比敏感度相关因素的初步探讨

目的:测试海军飞行员视觉对比敏感度函数(contrast sensitivity function,CSF),探讨对比敏感度的相关因素。方法:应用美国Stereo Optical Co.生产的OPTEC6500视觉检查仪对58例116眼飞行员进行明视、明视眩光、暮视、暮视眩光4种状态下5个空间频率的对比敏感度检查。结果:从均数曲线图中可见暮视和暮视眩光状态下CSF曲线的峰值在3c/d;明视和明视眩光状态下CSF曲线的峰值在6c/d;在各空间频率,双眼CSF值均高于单眼,差异有统计学意义(均为P<0.05);在各空间频率下,远距离CSF值均高于近距离,差异有统计学意义(均为P<0.05)。结论:海军飞行员视觉对比敏感度远距离CSF优于近距离,双眼CSF值高于单眼,本调查客观反映了海军飞行员CSF的分布特征。     

非球面与球面人工晶状体植入术后对比敏感度的比较

目的观察非球面人工晶状体（IOL）和球面IOL植入术后在视力相同的情况下其对比敏感度的差异。方法收集行超声乳化联合IOL植入术的年龄相关性白内障患者49例（60眼）,其中植入非球面IOL Tecnis ZA9003者24例30眼,植入球面IOL Sensar AR40e者25例30眼,所有病例术后裸眼LogMAR视力均〉0．1。术后3个月时采用CSV-1000对比敏感度测试仪分别测量明视、暗视和眩光状态下的对比敏感度,用F．A．C．T对比敏感度表测量近距离对比敏感度。结果在明视和暗视状态下的对比敏感度,非球面IOL组均高于球面IOL组,两组在空间频率6、12、18周／度时的差异均有统计学意义（P〈0．05）;暗视眩光状态下的对比敏感度,非球面IOL组高于球面10L组,两组在各空间频率的差异均有统计学意义（P〈0．05）。F．A．C．T对比敏感度测试卡测得的对比敏感度,非球面IOL组高于球面IOL组,两组在各空间频率的差异均有统计学意义（P〈0．05）。结论在传统的视力表检查视力正常和相同的情况下,非球面IOL植入术后较球面IOL植入术后患眼具有较好的对比敏感度,提示非球面IOL可以提高功能视力。     

标准及波前像差引导LASIK手术前后明暗环境下对比敏感度变化

目的 比较标准LASIK和波前像差引导LASIK手术前后在明、暗环境下对比敏感度变化.方法 选取接受标准LASIK或波前像差引导LASIK的中高度近视患者各30例,行明环境下和暗环境下对比敏感度检查,观察2组对比敏感度的变化.结果 明环境下对比敏感度,术前2组在各个空间频率下无差异(P＞0.05),术后波前组各个空间频率下对比敏感度均显著高于标准组(P＜0.05);在有眩光干扰情况对1.0 deg、0.7 deg空间频率下波前组术后对比敏感度增加幅度分别为0.200 4±0.377 1、0.163 9±0.315 1,显著大于标准组(0.058 4±0.295 1、0.056 0±0.234 8)(P＜0.05).暗环境下对比敏感度,术后波前组各等级通过率均大于标准组,但仅在有眩光对差异有统计学意义(P＜0.05).术后6个月,明环境对比敏感度有眩光情况下,波前组均显著超过术前水平(P＜0.05);标准组在6.3 deg(1.751 8±0.207 2)、4.0 deg(1.723 5±0.190 1)、2.5 deg(1.568 0±0.300 9)、1.6 deg空间频下显著超过术前水平,在1.0 deg、0.7Jeg空间频率下高于术前水平,但差异无统计学意义(P＞0.05).术后6个月,明环境对比敏感度在无眩光情况下,2组对比敏感度均未恢复至术前水平,但差异无统计学意义(P＞0.05).结论 波前像差引导的LASIK手术视觉质量优于标准LASIK.     

Q值引导的准分子激光原位角膜磨镶术后对比敏感度的变化

目的检测Q值引导的个体化切削模式（fine adjusted—customized ablation treatment,F—CAT）准分子激光原位角膜磨镶术（laser in situ keratomileusis，LASIK）术前术后对比敏感度和眩光敏感度，并与常规LASIK方法比较，评价该手术对对比敏感度的影响。方法使用德国WAVE-UGHT公司的ALLEGRETTO角膜地形图仪、ALLEGRETTO像差仪、ALLEGRETTO WAVE Eye—Q准分子激光系统，对23例（46眼）近视患者行F—CAT，22例（44眼）近视患者行常规的LASIK手术作为对照。使用CGT-1000对比敏感度仪检测两组患者在术前、术后第1个月及术后第3个月的对比敏感度和眩光敏感度。结果F—CAT组与常规组术后裸眼视力差异无显著性（P〉0．05）。F—CAT组角膜Q20值为-0．12±0．24。常规组为0．15±0．21，差别有显著性（P〈0．05）。F—CAT组术后球差增加5倍。常规组增加7倍。但两组间球差差异无显著性（P〉0．05）。术后第1个月及第3个月F—CAT组对比敏感度在各频段与术前比较均差异无显著性：常规组术后第1个月对比敏感度在各频段较术前下降．在4．0’及2．5’两频段与术前相比差异有显著性：术后第3个月对比敏感度略有回升．各频段与术前比较差别无显著性。F—CAT组与常规组术后第1个月及第3个月在4．0’及2．5’两频段差异有显著性（P〈0．05）。F—CAT组术后眩光敏感度与术前比较均差异无显著性。常规组术后第1个月眩光敏感度在4．0’、2．5’、1．6’三频段较术前下降。差异有显著性（P〈0．05）。术后第3个月眩光敏感度回升。各频段与术前比较差异无显著性。术后第1个月、第3个月两组间在4．0’及2．5’、1．6’频段差异有显著性（P〈0．05）。结论F—CAT术后，角膜中央Q值保持负值，减少球差增加的倍数。使患者的对比敏感度和眩光敏感度优于常规组。有更好的视觉质量。     

Contrast sensitivity

Spatial contrast is a physical dimension referring to the light-dark transition of a border or an edge in an image that delineates the existence of a pattern or an object. Contrast sensitivity refers to a measure of how much contrast a person requires to see a target. Contrast-sensitivity measurements differ from acuity measurements; acuity is a measure of the spatial-resolving ability of the visual system under conditions of very high contrast, whereas contrast sensitivity is a measure of the threshold contrast fur seeing a target. Today the most common methods for measuring contrast sensitivity are chart-based systems that can be mounted on the wall. These charts use test targets that are either sine-wave gratings or letters. Which specific chart a clinician selects should be guided by his or her purpose in using contrast sensitivity for patient management. In the research setting, chart selection should rest on ensuring that the scientific aims of the study are met. Contrast-sensitivity tests can provide useful information by revealing in some conditions visual loss not identifiable through visual acuity tests, by providing another method of monitoring treatments, and by providing a better understanding of visual performance problems faced by persons with vision impairment.     

Contrast sensitivity

This paper presents a few theoretical considerations about the contrast sensitivity, modalities of testing and changes of contrast sensitivity in different ophthalmologic diseases.     

Rod sensitivity relative to cone sensitivity in retinitis pigmentosa.

The present study evaluates rod sensitivity relative to cone sensitivity in retinitis pigmentosa patients. From perimetric measures of absolute thresholds to long- and short-wavelength stimuli, we find the results can be characterized in three different ways. For one group of patients it appears that only cone function is present in all parts of the visual field. For another group of patients, despite large losses in absolute sensitivity, rod sensitivity still exceeds cone sensitivity by at least the normal factor, suggesting concomitant rod and cone sensitivity losses. For a third group of patients it appears that central retinal thresholds are determined primarily by cones, midperipheral retinal thresholds determined by a composite of rod and cone function, and far- peripheral thresholds determined predominately by rods. The argument is put forward that the different groups of threshold results represent different disease mechanisms rather than different stages in the progression of a single disease process.     

Measuring contrast sensitivity

Contrast sensitivity defines the threshold between the visible and invisible, which has obvious significance for basic and clinical vision science. Fechner’s 1860 review reported that threshold contrast is 1% for a remarkably wide range of targets and conditions. While printed charts are still in use, computer testing is becoming more popular because it offers efficient adaptive measurement of threshold for a wide range of stimuli. Both basic and clinical studies usually want to know fundamental visual capability, regardless of the observer’s subjective criterion. Criterion effects are minimized by the use of an objective task: multiple-alternative forced-choice detection or identification. Having many alternatives reduces the guessing rate, which makes each trial more informative, so fewer trials are needed. Finally, populations who may experience crowding or target confusion should be tested with one target at a time.     

Orientation coherence sensitivity

We developed a global orientation coherence task for the assessment of global form processing along similar lines to the global motion coherence task. The task involved judgments of global orientation for an array of limited duration 1-D Gabors, some of which were signal (signal orientation) and some of which were noise (random orientation). We address two issues. First: Do motion and form global processing have similar dependencies? And second: Can global sensitivity be explained solely in terms of integrative function? While most dependencies (e.g., contrast, spatial scale, and field size) are similar for form and motion processing, there is a greater dependence on eccentricity for form processing. Sensitivity for global tasks involves more than just integration by filters broadly tuned for orientation. Results are best modeled by filters with narrowband orientation tuning that effectively segregate as well as integrate global information.     

Keratoplasty sensitivity.

Analysis of graft sensitivity showed a return to normal after 3 years in only one-third of the eyes. It is not known whether this is due to regeneration of abnormal or superficial nerve fibres. Contact lens wearers showed less sensitivity than spectacle wearers.     

Hastening orientation sensitivity

Previous perceptual learning studies have shown that sensitivity to subtle orientation differences improves with practice at oblique axes but not with practice at cardinal axes. The cause of this anisotropy in angular resolution is uncertain, and it is not known whether the same anisotropy pertains to temporal resolution-the minimum stimulus duration needed to achieve a specified angular resolution. Here, we investigated the hypothesis that cardinal improvements were previously absent because long stimulus durations yielded maximal precision, even at the start of training. Accordingly, we exploited the relatively imprecise responses that occur naturally when masked stimuli are presented for extremely brief durations. After 110,000 trials were completed over seven daily sessions, temporal resolution improved by 51% at cardinal axes and by 86% at oblique axes. This hastening of the visual response was accompanied by significant improvements in angular resolution, which were specific to the trained axis. The data demonstrate plasticity in the response to cardinal orientations and indicate that sufficient initial levels of neural imprecision may be necessary for perceptual learning.