干眼病患者角膜表面规则性及人工泪液对角膜表面规则性的影响

目的　评价干眼病患者的角膜表面规则性及人工泪液对其角膜表面规则性的影响。方法　应用TMS 1角膜地形图仪检测正常人 33例 ( 6 4只眼 )及干眼病患者 2 2例 ( 42只眼 )的角膜表面规则指数 (surfaceregularityindex ,SRI)、表面不对称指数 (surfaceasymmetryindex ,SAI)及角膜预测视力(potentialvisualacuity ,PVA) ,并对干眼病患者应用人工泪液前后角膜表面规则性及PVA的变化进行观察。结果　干眼病患者的SRI、SAI及PVA值分别为 0 .31± 0 .2 2、0 .30± 0 .16及 2 0 /17.89± 2 0 /3.0 4;而正常人分别为 1.2 8± 0 .73、1.0 5± 1.17及 2 0 /33.45± 2 0 /13.99。干眼病患者的SRI和SAI值较正常人明显升高 ,PVA值则明显降低 ,各组间比较差异有非常显著性 (P <0 .0 0 1)。干眼病患者的平均散光度( 2 .10± 1.96 )D明显较正常人 ( 1.13± 0 .5 3)D高 (P =0 .0 2 )。在干眼病患者中 ,SRI与SAI与角膜荧光素染色程度呈正相关 (SRI:P =0 .0 0 5 ;SAI:P =0 .0 16 ) ,而平均PVA与平均实际矫正视力比较差异无显著性。干眼病患者角膜地形图中对称蝴蝶结形所占的比例较正常人明显降低 ,而不规则形者所占比例则明显升高。干眼病患者在滴用人工泪液后 ,SRI、SAI和平均散光度均明显降低 (P值分别为<0 .0 0 1,<0 .0 0     

LASIK术后角膜地形图和波阵面像差的改变及其与视觉质量的关系

目的探讨标准LASIK术后角膜地形图、波阵面像差改变与视觉质量的关系。方法检查LASIK术后患者133人(266眼),根据术前等效球镜度(sphericalequivalent,SE)分为低、中、高、超高度近视4组。分别于术后1周、1个月、3个月、6个月、1年检查裸眼视力(uncorrectedvisualacuity,UCVA)、SE、角膜地形图、波阵面像差及满意度调查。结果术前平均最佳矫正视力(bestcorrectedvisualacuity,BCVA)为1.06±0.09,术后1年平均UCVA为1.09±0.12,角膜地形图形状以平滑型为主(75.19%),视觉质量满意度为96.99%。术后模拟角膜计读数(simulatedkeratometry,SimK)等效值、SimK差较术前明显减小(P<0.01)。术后不同时期间比较SimK值无显著改变(P>0.05);分组比较低、中度组术后1个月、3个月、6个月及1年间SimK值无显著变化(P>0.05),但高度和超高度组术后6个月内SimK值增大,差异有显著性(P<0.05),6个月及1年间无明显改变(P>0.05)。术后各组总体像差均方根值(rootofmeansquareofgeneralaberration,RMSg)明显减小(P<0.01),高阶像差均方根值(rootofmeansquareofhigheraberration,RMSh)增大(P<0.05),C4减小,C7、C8、C12增大,且C4、RMSg的改变与术前SE有相关性(P<0.01)。角膜地形图Simk值及波阵面像差与术后视力无线性相关性(P>0.05)。结论术后6个月内低、中度近视地形图Simk值较稳定,而高度近视地形图Simk值6个月后才趋于稳定。术后RMSg减小,RMSh增加。角膜地形图Simk值及波阵面像差与术后视力无线性相关性。但角膜地形图的形态、Zernike函数C7增大、C12增大与术后视觉质量关系密切。     

ORK与LASIK术后角膜地形图变化的对比研究

目的:探讨角膜波面像差引导的准分子激光个体化屈光手术(optimized refractive keratectomy-customized ablation,ORK)治疗高度近视患者术后角膜表面规则性和对称性情况。方法:对50例100眼高度近视患者行角膜波面像差引导的准分子激光个体化屈光手术治疗,对同期50例100眼高度近视患者用传统LASIK治疗,观察两组疗效,并采用角膜地形图检查仪测量两组术后6mo的角膜地形图变化[包括角膜曲率,K1,K2,表面非对称指数(surface asym-metry index,SAI),表面规则指数(surface regularity index,SRI)]。结果:与术前比较,两组术后角膜曲率、K1,K2,SAI,SRI降低(均为P<0.05)。ORK组术后6mo SAI,SRI改善优于传统组(均为P<0.05)。结论:角膜波面像差引导的准分子激光个体化屈光手术与传统LASIK比较,角膜波面像差引导的准分子激光个体化屈光手术治疗的患者术后6mo角膜规则性和对称性优于应用传统LASIK治疗的患者。     

软性角膜接触镜与透气性硬性角膜接触镜对像差的影响

目的 分析配戴软性角膜接触镜、透气性硬性角膜接触镜（rigid gas-permeable contact lens,RGP）患者波前像差及角膜地形图在配戴前后的变化,探讨角膜接触镜对人眼屈光系统成像质量的影响.设计前瞻性随机对照临床研究.研究对象近视眼患者41例（80眼）.方法 软镜组20例（40眼）配戴软性角膜接触镜,RGP组21例（40眼）配戴RGP镜片,患者治疗前后作角膜地形图及波前像差检查,随访观察12个月.主要指标观察配戴接触镜治疗前后角膜地形图及波前像差的变化.结果 软镜组患者治疗后角膜表面规则指数（surface regularityindex,SRI）及角膜表面非对称指数（surface asymne-tryindex,SAI）有所增加,而RGP组SRI及SAI轻度下降;戴镜条件下,两组的整体波前像差（软镜组：0.58;RGP组：0.91）均低于治疗前裸眼的整体波前像差（软镜组：0.71;RGP组：1.21）;配戴后裸眼条件下,RGP组整体像差低于治疗前,且以低阶像差下降为主,而软镜组整体像差高于治疗前,各阶像差呈均匀上升趋势.结论 良好配适状态下的角膜接触镜均可使像差减小,使患者获得优质的光学矫正.     

屈光不正儿童睫状肌麻痹前后角膜地形图的比较分析

目的观察屈光不正儿童睫状肌麻痹前后角膜地形图两条主子午线角膜曲率Kf及Ks、角膜散光及轴向、SRI及sAI的变化。方法采用TNs-4型计算机辅助角膜地形图仪,对53例106眼屈光不正儿童(远视50眼,近视56眼)分别于其睫状肌麻痹前、后进行角膜地形图检查。采用两样本均数比较的配对t检验对睫状肌麻痹前后角膜地形图的两正交子午线角膜屈光力最大值Ks、角膜屈光力最小值Kf、角膜散光值、散光轴向、角膜表面、规则指数(SRl)、角膜表面非对称指数(SAl)进行统计分析。结果睫状肌麻痹前后Ks、Kf、角膜散光值、散光轴向、SRI、SAI的比较均无显著性差异(P>0.05)。结论儿童睫状肌麻痹后角膜屈光力、散光轴向、SRI、SAI均无变化,     

近视散光患者角膜形态对高阶像差的影响

目的 探讨近视散光患者高阶像差的分布特点及角膜形态对其的影响.方法 用wavescan wavefront system波前像差仪对LASIK术前281例（434眼）近视散光患者进行客观测量,用TMS-4角膜地形图仪获得角膜表面规则指数（surface regularity index,SRI）、角膜表面不对称指数（surface asymmetry index,SAI）以及角膜表面形态.对屈光度、SRI和SAI与高阶像差作相关分析,将患者分别按角膜形态分为5组,对各组间的高阶像差的均方根值（root mean square,RMS）作秩和检验.结果 6.0 mm瞳孔直径下的总高阶像差（root mean square of higher order aberrations,RMSh）的均方根值为（0.286±0.098）μm,从3阶至6阶大致呈递减趋势,其中以3阶彗差、三叶草和4阶球差的均数最大.屈光力和SRI与RMSh没有显著的相关性,SAI与RMSh呈正相关,Pearson相关系数为0.161,P值为0.001.SAI值对高阶像差的影响较SRI值大,尤其是SRI值较低的患者,RMSh值随SAI的增高而增大,主要表现为3阶彗差和4阶球差的增大.角膜形态为不规则形和不对称领结形时高阶像差最大,主要表现为三叶草和3阶彗差的增大.结论 6.0 mm瞳孔直径时,最主要的高阶像差是3阶彗差、三叶草和4阶球差.角膜形态为不规则形和不对称领结形时高阶像差最大.SAI对高阶像差的影响比SRI大.     

不同近视程度及准分子激光屈光术后角膜地形图分析

目的 分析不同近视程度患者的角膜地形图及准分子激光术前、术后角膜地形图的差异,了解不同近视程度及术后角膜表面形态的改变.方法 回顾性分析2004年在我院行准分子激光屈光性手术的159例患者的角膜地形图资料,比较SRI、SAI、CLY等反映角膜表面形态的参数,采用SPSS 13.0统计软件进行统计分析.结果 不同近视程度组间角膜地形图比较示:CYL的差异有统计学意义(P＜0.05),而SRI、SAI各组间没有明显差异P＞0.05);准分子激光屈光性手术前后角膜地形图参数分析示:术后CYL、SRI、SAI均有显著变化(P＜0.01),其差异具有统计学意义.结论 不同程度的近视患者间角膜表面的规则程度、对称性没有显著差异,而散光程度随近视度数增大而有所增加.准分子激光术后角膜规则性、对称性、散光程度均有显著改变,行准分子激光术矫正屈光不正时应更加注重角膜形态的改变,以减少术后视觉质量及光学问题的发生.     

中西医结合治疗肝肾阴虚型干眼症的疗效观察

目的:通过对肝肾阴虚型干眼症患者采用“复明片”加减联合睑板腺疏通法临床治疗的疗效观察,说明中西医结合治疗肝肾阴虚型干眼症可以收到良好的效果。方法:对符合干眼症诊断标准的400例患者的性别、年龄、症状、临床表现进行详细记录并进行严格的中医辨证分型,并对辩证为“肝肾阴虚”型的干眼症患者90例随机分三组治疗:A组30例给予“复明片”加减联合睑板腺疏通法加人工泪液治疗;B组30例给予睑板腺疏通法加人工泪液治疗;C组30例给人工泪液治疗。三组患者的自觉症状、泪液分泌试验（SchirmerⅠtest,SⅠt）、泪膜破裂时间（tear break-up time,BUT）、角膜荧光素染色(fluorescein staining,FL)和角膜地形图的角膜表面规则指数（surface regularity index,SRI）和角膜表面不规则指数（surface asymmetry index,SAI）结果作为观察指标,对观察数据进行统计分析,每组治疗前后行配对资料的秩和检验;对三组的疗效行多个样本间两两比较的秩和检验。结果:A组观察指标改善情况及疗效明显优于B,C两组;B组的又优于C组;三组的有效率分别是90.0%,73.3%和53.3%;结论:对肝肾阴虚型干眼症,采用“复明片”加减联合睑板腺管疏通术和人工泪液的治疗方法可以取得良好的治疗效果。睑板腺功能障碍（MGD）直接相关或合并MGD是干眼症的病因之一;同时角膜地形图可以协助诊断和评价干眼症的严重程度和治疗效果。      

圆锥角膜配戴透气性角膜接触镜相关性干眼疗效评价

目的 观察维生素A棕榈酸酯眼用凝胶对圆锥角膜配戴硬性透气性角膜接触镜(RGP)相关性干眼症的临床疗效.方法 将90例透气性角膜接触镜相关性干眼症圆锥角膜患者随机分为3组,每组30例(60眼):A组使用人工泪液滴眼液,6次,d,1滴/次;B组使用维生素A棕榈酸酯眼用凝胶,3次,d,1滴/次;C组在使用人工泪液滴眼液(6次/d,1滴/次)后15min再用维生素A棕榈酸酯眼用凝胶(3次/d,1滴/次).观察各组患者用药前1天与用药后第3、7、14天的眼部症状评分、泪膜破裂时间(BUT)、Schirmer Ⅰ试验(S Ⅰ T)、角膜荧光染色(Fl)评分变化.结果 在用药7天后三组患者的干眼症状、BUT和Fl染色均较治疗前有明显改善(P＜0.05),三组患者SⅠT值治疗前后差异均无统计学意义(P＞0.05).各组患者在治疗14天后和治疗7天时测得的各项指标差异无统计学意义(P＞0.05).A组与B组对眼部症状、BUT和SⅠT的改善作用差异无统计学意义(P＞0.05);B组较A组改善角膜Fl染色作用更明显,差异有统计学意义(P＜0.05).C组对改善干眼症状、BUT和Fl染色作用优于A组(P＜0.05).SⅠT和Fl染色治疗前后比较,C组和B组,差异无统计学意义(P＞0.05),C组对改善干眼症状和BUT作用优于B组(P＜0.05).结论 维生素A棕榈酸酯眼用凝胶能够促进角膜上皮损伤愈合,缓解圆锥角膜患者配戴硬性透气性角膜接触镜所致干眼症状,具有临床应用价值.     

个性超声乳化切口并不同类型人工晶状体植入术后角膜散光和视觉质量的比较

目的 比较常规上方透明角膜切口与角膜地形图引导切口并植入不同类型人工晶状体(IOL)的白内障合并角膜散光患者术后角膜散光、波前像差的差异.方法 采用前瞻性随机对照临床研究方法.对术前存在角膜散光的年龄相关性白内障患者90例(90只眼),采用分段随机分组法分为3组:常规上方透明角膜切口超声乳化白内障吸除联合AcrySof SN60AT IOL植入组(A组),角膜地形图引导切口超声乳化白内障吸除联合AcrySof SN60AT IOL植入组(B组),角膜地形图引导切口超声乳化白内障吸除联合AcrySof SN60WF IOL植入组(C组),术后1周、1个月、3个月及6个月复查角膜地形图,术后3个月使用以Tscheming原理建立的波前像差分析仪测量3组患者术后IOL眼的像差,并在瞳孔直径为6 mm条件下比较3、4、5、6阶像差,总体高阶像差,总体像差及球差、彗差的均方根(RMS)值.统计学分析方法采用重复测茸资料方差分析、卡方检验、单因素方差分析及SNK法两两比较.结果 角膜地形图检查显示术前各组散光值差异无统计学意义(F=0.08,P>0.05),3组患者角膜散光经矢量分解为J0,J45和P,经重复测量资料方差分析,对于反映垂直和水平方向散光的J0和矢量长度的P,A组与B、C组比较差异有统计学意义(F=9.54,18.69;均P<0.01),而B、C组比较无统计学意义(P>0.05),处理组与时间有交互效应(F=13.45,50.22;均P<0.01),3组患者手术前后不同时间的散光值差异有统计学意义(F=74.33,92.11;均P<0.01);术后3个月波前像差检查显示,A组总体像差(RMSg)、彗差、高阶像差(RMSh)、3阶像差(RMS3)及5～6阶像差显著高于B组及C组(F=93.40,471.94,176.95,216.99,44.37,37.19;均P<0.01),而且A组RMS4及球差显著高于C组(q=25.30,26.23;均P<0.01),但RMS4及球差与B组比较差异无统计学意义(q=0.57,2.34;均P>0.05),B组RMS4,RMSh,RMSg及球差显著高于C组(q=24.73,7.90,6.41,23.89;均P<0.01).结论 对于合并角膜散光的白内障患者,角膜地形图引导超声乳化切口联合负球面像差IOL植入可以矫正术前的角膜散光,减少IOL眼的球差、高阶像差及总像差,从而提高患者的视觉质量.     

The effect of artificial tears on corneal surface regularity in patients with Sjögren syndrome

PURPOSE: To evaluate the effect of artificial tears on the topographic parameters associated with corneal surface regularity in patients with Sj?gren syndrome. METHODS: A total of 38 eyes of 20 patients with Sj?gren syndrome were evaluated prospectively. The mean age of the patients was 50.5 +/- 15.3 years (range, 28-76). Corneal topography with the Topographic Modeling System (TMS-2, Tomey) was performed before and after the instillation of artificial tears. The surface regularity index (SRI), surface asymmetry index (SAI), potential visual acuity (PVA) and mean astigmatism were compared in dry eyes before and after the instillation of artificial tears. RESULTS: Before the instillation of artificial tears SAI, SRI, PVA and mean antigmatism values were found to be 1.37 +/- 1.47, 0.74 +/- 0.42, 20/30.92 +/- 20/8.12 and 1.53 +/- 1.47 D, respectively. In corneal topography performed after the instillation of artificial tears SAI, SRI, PVA and mean astigmatism values were 0.71 +/- 0.82, 0.43 +/- 0.36, 20/25.92 +/- 20/5.55 and 1.08 +/- 1.18, respectively. When compared statistically, the SRI, SAI, and mean astigmatism all decreased significantly and the PVA improved (p = 0.0001). CONCLUSION: Irregular corneal surface in dry eye patients affects optical quality. The statistically significant improvement observed in SRI and SAI values after the instillation of artificial tears also improves the PVA that is especially related to SRI.     

Effect of artificial tears on corneal surface regularity,contrast sensitivity,and glare disability in dry eyes

OBJECTIVE: To investigate the effects of artificial tears on corneal surface regularity and visual function in dry eyes. DESIGN: Nonrandomized, comparative trial. PARTICIPANTS: Forty patients (40 eyes) with dry eyes with (group 1, n = 15 eyes) or without (group 2, n = 25 eyes) punctate epithelial keratopathy and a normal control group of 20 individuals (20 eyes) with no ocular abnormalities (group 3). METHODS: In both dry and normal eyes, the surface regularity index (SRI), surface asymmetry index (SAI), and potential visual acuity (PVA) were measured by computer-assisted videokeratography (TMS-1; Computed Anatomy, New York, NY). Spatial-contrast sensitivity and glare disability were also measured before and 1 minute after instillation of artificial tears. MAIN OUTCOME MEASURES: Differences in SRI, SAI, PVA, spatial-contrast sensitivity, and glare disability between groups, before instillation of tears, and within groups, after instillation of tears. RESULTS: Compared with group 3, eyes in group 1 had significantly worse SRI, SAI, PVA, and contrast sensitivity (incomplete glare disability data precluded analysis) before instillation of artificial tears. Differences in corneal surface regularity and visual function between groups 2 and 3 were not significant except for a significantly increased glare disability at low spatial frequency (1.5 cycles per degree [cpd]) in group 2. Significant improvement in SRI, SAI, PVA, and contrast sensitivity were observed after instillation of artificial tears in group 1. In groups 2 and 3, the only significant changes were improvement in glare disability at 1.5 cpd and worsening of the SRI, respectively. CONCLUSIONS: Tear film changes in dry eye patients may lead to irregularities on the corneal surfaces, causing glare disability. However, these changes may be too subtle in the early stages of dry eyes to be detected by corneal topography or contrast sensitivity measurements. Significant improvement in SRI, SAI, PVA, and contrast sensitivity were found after instillation of artificial tears in dry eyes with punctate epithelial keratopathy.     

Corneal surface regularity and the effect of artificial tears in aqueous tear deficiency.

PURPOSE: To evaluate corneal surface regularity and the effect of artificial tears on the regularity of the corneal surface in dry eye. DESIGN: A prospective, clinic-based, case-control study. PARTICIPANTS: A total of 64 eyes of 33 normal subjects and 42 eyes of 22 patients with aqueous tear deficiency were evaluated. METHODS: Indices of the TMS-1 corneal topography instrument (Tomey Technology, Cambridge, MA) were used to evaluate corneal surface regularity and potential visual acuity (PVA) in patients with aqueous tear deficiency dry eye before and after the instillation of artificial tears and in normal subjects. The TMS-1 topographic maps were classified into round, oval, symmetric bow-tie, asymmetric bow-tie, and irregular patterns. MAIN OUTCOME MEASURES: The surface regularity index (SRI), surface asymmetry index (SAI), PVA index, and topographic pattern of the TMS-1 were compared between normal and dry eyes and in dry eyes before and after the instillation of artificial tears. RESULTS: The SRI and SAI were significantly elevated and the PVA was significantly reduced in dry eye patients compared with normal subjects: 0.31+/-0.22, 0.30+/-0.16, and 20/17.89+/-20/3.04, respectively, in normal subjects and 1.28+/-0.73, 1.05+/-1.17, and 20/33.45+/-20/13.99, respectively, in patients with dry eye (P<0.001 for all indices). The average amount of astigmatism was also increased in dry eyes (2.10+/-1.96 prism diopters) compared with normal eyes (1.13+/-0.53 prism diopters, P = 0.02). In dry eyes, the SRI and SAI were positively correlated with corneal fluorescein staining scores (P = 0.005 for SRI and P = 0.016 for SAI). The mean PVA was not significantly different from the mean actual corrected visual acuity. The dry eyes had a significantly lower percentage of symmetric bow-tie patterns and a greater percentage of irregular patterns on topographic maps than normal eyes. After the instillation of artificial tears, the SRI, SAI, and mean astigmatism all decreased significantly (P<0.001 for SRI, P<0.002 for SAI, P = 0.04 for astigmatism) and the PVA improved (P<0.001) in dry eyes. An irregular topographic pattern was observed in 45.24% of dry eyes, and this decreased to 30.95% after the instillation of artificial tears (P<0.005). CONCLUSIONS: Patients with aqueous deficiency have an irregular corneal surface that may contribute to their visual difficulties. The SRI and SAI could be used as objective diagnostic indices for dry eye as well as for evaluating the severity of this disease and the effect of artificial tears. Artificial tears have the secondary benefit of smoothing the corneal surface in dry eye.     

Evaluations of wavefront aberrations and corneal surface regularity in dry eye patients measured with OPD Scan III

AIM: To compare the wavefront aberrations and corneal surface regularity between dry eye (DE) patients and normal subjects and assess its diagnostic performance for DE measured with OPD Scan-III. METHODS: Fifty right eyes of 50 DE patients and 31 right eyes of normal subjects were included. The examinations for ocular surface including logarithm of the minimum angle of resolution best-corrected distance visual acuity (logMAR BCVA) the ocular surface disease index (OSDI), tear film break-up time (TBUT) and corneal fluorescein staining (CFS). OPD Scan-III was used to measure anterior corneal aberrations including total corneal aberrations, high order aberration (HOA), coma, trefoil, spherical aberration (SA), standard deviation of corneal power (SDP), surface regularity index (SRI) and surface asymmetry index (SAI). Statistical analysis were assessed with nonparametric tests and Spearman’s correlations. All parameters were also analyzed for sensitivity, specificity, and receiver operating characteristics (ROC) curves. RESULTS: Wavefront aberrations parameters including total corneal aberrations, HOA, coma, trefoil, and SA in DE group were significantly higher than those in normal group (P<0.001). Corneal surface regularity parameters including SRI and SAI in DE group were significantly higher than both in normal group (P<0.05). All the wavefront aberrations parameters had significant correlations with ocular surface parameters (P<0.05). The logMAR BCVA had positive correlations with SAI and SRI (all P<0.001). CFS scores had positive correlations with SAI and SRI (all P<0.001). All the wavefront aberrations parameters showed good diagnosis sensitivity and specificity, however, the corneal regularity parameters showed only good specificity but poor sensitivity. The cut-off value selected for trefoil in diagnosis DE showed the highest area under the curve (AUC, 0.921) values as compared to the other parameters with sensitivity of 0.955 and specificity of 0.867. CONCLUSION: Wavefront aberrations and corneal surface regularity are increased in DE patients and also correlated with ocular surface parameters. Wavefront aberrations parameters have potential to be indicators to diagnosis and monitor DE.     

Assessing the severity of keratitis sicca with videokeratoscopic indices

PURPOSE: To determine the correlation between the regularity indices of the Tomey TMS-2N computerized videokeratoscopy (CVK) instrument (Tomey, Waltham, MA) with conventional measures of dry eye symptoms and disease. DESIGN: A retrospective, clinic-based, case-control study. PARTICIPANTS: A total of 16 eyes of 16 asymptomatic normal subjects and 74 eyes of 74 patients with reports of ocular irritation. METHODS: Corneal surface regularity and potential visual acuity indices of the Tomey TMS-2N CVK instrument were evaluated in patients with ocular irritation symptoms and in normal subjects. MAIN OUTCOME MEASURES: The surface regularity index (SRI), surface asymmetry index (SAI), potential visual acuity index (PVA), and irregular astigmatism index (IAI) of the Tomey TMS-2N were compared between normal and dry-eye patients. Severity of dry-eye symptoms was assessed with a validated questionnaire. Schirmer 1 test (without anesthesia), biomicroscopic meibomian gland evaluation with a composite severity score (MGD score), fluorescein tear break-up time (TBUT), and corneal fluorescein staining were performed. The correlations between CVK indices of the Tomey TMS-2N and the symptom severity score, Schirmer 1 test, MGD score, TBUT, and corneal fluorescein staining score were studied. RESULTS: Dry-eye patients had greater mean symptom severity scores, lower Schirmer 1 test scores, greater MGD scores, more rapid TBUT, and greater total corneal fluorescein staining scores (P < 0.001 for all parameters). The SRI, SAI, and IAI were all significantly greater in dry-eye patients than normal subjects. These were 0.46 +/- 0.36 (normal) versus 1.09 +/- 0.76 (dry) for the SRI (P = 0.0017), 0.30 +/- 0.15 (normal) versus 0.90 +/- 1.09 (dry) for the SAI (P = 0.0321), and 0.42 +/- 0.28 (normal) versus 0.56 +/- 0.24 (dry) for the IAI (P = 0.0321). The PVA index was significantly lower in the dry-eye patients (0.89 +/- 0.13) than normal eyes (0.68 +/- 0.23; P = 0.0008). The SRI, SAI, and IAI were positively correlated with total and central corneal fluorescein staining scores (P < 0.00001 for all indices). An SRI (> or =0.80), SAI (> or =0.50), and IAI (> or =0.50) had sensitivities in predicting total corneal fluorescein staining (score > or = 3) of 89%, 69%, and 82%, respectively. The specificity of these indices was 80%, 78%, and 82%, respectively. In all 90 eyes, the mean SRI was greater in subjects older than 50 years (P = 0.012) compared with younger patients, whereas no age effect was noted in the dry-eye patients. The SRI and PVA index showed better correlation with symptoms of blurred vision than the best-corrected visual acuity. CONCLUSIONS: Patients with ocular irritation have an irregular corneal surface that may contribute to their irritation and visual symptoms. Because of their high sensitivity and specificity, the regularity indices of the Tomey TMS-2N have the potential to be used as objective diagnostic indices for dry eye, as well as a means to evaluate the severity of this disease.     

High-speed videotopographic measurement of tear film build-up time

PURPOSE: To detect tear film regularity changes in the 15 seconds after a blink, by using a new high-speed videotopographic method. METHODS: The new system, based on a standard corneal topograph, allows registration of four photokeratoscopic images per second. Altogether, 15 eyes of 15 healthy volunteers and 7 eyes of 7 patients with dry eye were examined in this prospective preliminary study. The main outcome measures were changes in surface regularity index (SRI), surface asymmetry index (SAI), and corneal power. RESULTS: The corneal surface became more regular in the first few seconds after a blink. In healthy eyes, the trend line of SRI and SAI decreased (improved) significantly (P < 0.001) after a blink, in 10 of 15 eyes for the SRI and in 13 of 15 for the SAI. In the typical cases, the trend line for SRI reached its minimum level, on average, at 7.1 +/- 3.9 seconds after a blink and that for the SAI at 5.4 +/- 2.7 seconds. Similar trends were found in the dry-eye group. The changes in keratometric measures were small (mean range, <1.5% of the absolute value) and showed no definite trends. CONCLUSIONS: High-speed videotopography provides the possibility of quantitative measurement of tear-film dynamics and may have clinical value in the management of ocular surface disorders. After a blink, it takes the tear film approximately 3 to 10 seconds (tear film build-up time) to reach the most regular state. However, despite surface-regularity changes, the measured corneal powers are stable.     

Corneal topographical study of the effect of lacrimal punctum occlusion on corneal surface regularity in dry eye patients.

PURPOSE: To compare topographic indices of surface regularity in dry eye patients and in normal subjects (controls) and to investigate the short-term effect of lacrimal punctal plugs on these indices in dry eye patients. METHODS: The surface regularity index (SRI) and surface asymmetry index (SAI) of the TMS-2 corneal topographic modelling system were used to evaluate corneal surface regularity in 20 eyes of 10 dry eye patients before and after the insertion of Herrick silicon lacrimal plugs (Lacrimedics, Rialto, CA, USA) and in 24 eyes of 12 normal subjects as controls. RESULTS: SRI and SAI were significantly lower in controls than dry eye patients (p=0.00). Median SRI was 1.72 in dry eye patients before punctal occlusion and 0.525 in the control group. Median SAI was 1.305 in dry eye patients and 0.240 in controls. After lacrimal punctal occlusion, Schirmer test results and fluorescein breakup time increased in nine patients and remained the same in one patient. After occlusion, the SRI decreased in 9 eyes, and increased in 11 (p=0.970); SAI decreased in 13 eyes and increased in 7 (p=0.135). CONCLUSIONS: No significant change in topographic indices of corneal surface irregularity could be detected in severe dry eye patients with lacrimal punctal plugs in the short-term follow-up.