关注眼内散射光对人工晶状体眼视觉质量的影响

随着人们生活水平的提高,白内障患者对术后视功能的期望越来越高,不仅要有良好的视力,而且要求满意的视觉质量。人工晶状体（IOL）眼散射光的大小成为评价患者术后视觉质量的重要参数,患者术后一系列异常闪光感现象的出现均与其相关。IOL植入术后,引起IOL眼散射光增大的因素主要包括IOL的材质、IOL边缘设计、手术操作及后发性白内障（PCO）和瞳孔直径的影响。围绕关注眼内散射光对IOL眼视觉质量的影响,从而提高手术质量和患者的视觉质量这一主题,从眼内散射的作用机制、影响因素等方面进行阐述。     

SMILE术后散射的变化特征及相关影响因素

目的探讨SMILE术后眼内散射的变化,并对其相关影响因素进行分析。方法前瞻性病例研究。选取拟行SMILE手术的近视及近视散光患者67例（67眼）,应用C-quant散射仪分别测量患者手术前、术后1周、术后1个月、术后3个月及术后6个月眼内散射光计量值,并与年龄、球镜度、等效球镜度、CCT、角膜平均曲率值（Km）、角膜曲率半径等做相关分析,同时采用Pearson相关分析术后散射光计量值变化与角膜帽直径、小切口大小、切削深度、切削比、剩余角膜厚度（RBT）、RBT／CCT、能量等关系。结果SMILE手术前、术后1周、术后1个月、术后3个月、术后6个月的散射光计量值分别为0．93±0．16、0．97±0．14、0．94±0．17、0．94±0．17、0．90±0．17,术后1周散射光计量值较术前稍增加,但差异无统计学意义,各时间点散射光计量值比较差异无统计学意义（F=2．253,P〉0．05）;术后散射光计量值的变化与术中相关参数无明显相关性,仅在术后3个月散射光计量值与切口大小呈较弱正相关（r=0．356,P〈0．01）。结论SMILE术后散射光计量值较术前虽有变化,但变化不明显。术后由散射变化造成视觉质量下降的可能性较小。     

准分子激光前弹力层下角膜磨镶术前后散射特征及相关因素分析

目的 研究准分子激光前弹力层下角膜磨镶术（SBK）矫正屈光不正手术前后的散射特征,并分析其相关因素。方法 前瞻性临床研究。行SBK手术的近视及近视散光患者46例（92眼）,男29例,女17例,年龄18～39岁,平均（24.0±5.4）岁;等效球镜度为-4.75～-11.13 D,平均（-6.70±1.50）D;散光度为0～2.50 D,平均（0.68±0.58）D。手术前,采用Pentacam眼前节分析仪测量平均曲率值、角膜中央厚度等。手术前及手术后第1天、第1周、第1个月,应用C-Quant散射光计量仪测量患者的散射值。对所得数据分别应用重复测量的方差分析、配对t检验及Pearson相关进行分析。结果 SBK手术前眼内散射光计量值平均为0.90±0.13,手术后第1天、第1周、第1个月眼内散射光计量值分别为0.96±0.13、0.98±0.10、0.99±0.09,与术前比较,术后各个随访时间点散射均增加（F=24.94,P＜0.05）。经Pearson相关分析,手术前散射光计量值与等效球镜度、平均曲率值、角膜中央厚度的相关性无统计学意义;手术后各时间点散射光计量值增加量与术前散射光计量值水平呈负相关（r=-0.47、-0.67、-0.78,P均＜0.05）,与术前等效球镜度、切削深度的相关性无统计学意义。结论 SBK术后早期散射增加可能是影响视觉质量的因素之一,术前散射光计量值愈低的患者术后增加量愈明显。     

准分子激光前弹力层下角膜磨镶术前后散射特征及相关因素分析

目的研究准分子激光前弹力层下角膜磨镶术（SBK）矫正屈光不正手术前后的散射特征．并分析其相关因素。方法前瞻性临床研究。行SBK手术的近视及近视散光患者46例（92眼）,男29例,女17例,年龄18-39岁,平均（24．0±5．4）岁;等效球镜度为-4．75--11．13D,平均（-6．70±1．50）D;散光度为0-2．50D,平均（0．68±0．58）D。手术前,采用Pentacam眼前节分析仪测量平均曲率值、角膜中央厚度等。手术前及手术后第1天、第1周、第1个月,应用C-Quant散射光计量仪测量患者的散射值。对所得数据分别应用重复测量的方差分析、配对t检验及Pearson相关进行分析。结果SBK手术前眼内散射光计量值平均为0．90±0．13,手术后第1天、第1周、第1个月眼内散射光计量值分别为0．96±0．13、0．98±0．10、0．99±0．09,与术前比较,术后各个随访时间点散射均增加（F=24．94,P〈0．05）。经Pearson相关分析。手术前散射光计量值与等效球镜度、平均曲率值、角膜中央厚度的相关性无统计学意义;手术后各时间点散射光计量值增加量与术前散射光计量值水平呈负相关（r=-0．47、-0．67、-O．78,P均〈0．05）,与术前等效球镜度、切削深度的相关性无统计学意义。结论SBK术后早期散射增加可能是影响视觉质量的因素之一,术前散射光计量值愈低的患者术后增加量愈明显。     

不同类型年龄相关性白内障眼内散射光的检测及其临床意义

背景 视力检查是传统的评价视觉质量的标准,但近年来的研究发现,仅用视力指标评价白内障患者术后的视觉质量是不全面的,因此对比敏感度、眼内散射光等相关指标被越来越多地用于白内障患者视觉质量评估的临床应用中. 目的 应用C-quant散射光仪测量不同类型白内障眼内散射光值,探讨白内障形态与人眼视功能损害之间的关系.方法 采用非随机病例对照研究设计.纳入单纯年龄相关性白内障患者40例80眼,根据LOCSⅢ评分标准分为核性白内障22眼、皮质性白内障19眼、混合性白内障23眼、后囊下白内障16眼,应用C-quant测量眼内散射光值,比较不同类型白内障眼内散射光值的差异,并分析不同组内年龄、最佳矫正视力(BCVA)与眼内散射光值的相关性.收集年龄匹配的正常人作为正常对照组. 结果 白内障组共有62眼顺利完成C-quant眼散射光值的检查,完成率为77.5％,正常对照组检查完成率为100％.完成检查的白内障眼平均散射光值为(2.06±0.88) log,正常对照组为(1.25±0.87) log,差异有统计学意义(t=3.251,P＜0.01).核性白内障患者眼内平均散射光值为(1.96±0.42) log,皮质性白内障为(1.91±0.16) log,混合性白内障为(2.05±0.19)log,后囊下白内障为(2.48±0.66) log,差异有统计学意义(F=2.156,P=0.019),其中后囊下白内障产生眼内散射光最高,其次为混合性.核性白内障组眼内散射光值随着年龄的增加而增大,回归方程为Y=0.0010X+1.025(r=0.455,P＜0.05),混合性和后囊下白内障眼内散射光值与BCVA相关性均不明显(r=-0.240、-0.235,P＞0.05),而核性白内障和皮质性白内障组眼内散射光值与BCVA均呈负相关(r=-0.590、-0.697,P＜0.01). 结论 白内障患者术前可以使用C-quant散射光检测仪评估核性和皮质性白内障患者的视觉功能情况,因为后囊下白内障对患者视觉质量产生更大的影响,眩光等症状出现早,应及早进行手术治疗.     

人眼视网膜母细胞瘤的组织培养

视网膜母细胞瘤(retinoblastoma,简称RB)是一种原发于视网膜组织的恶性眼内肿瘤。好发年龄为出生至7岁。发病率及死亡率都较高。是一种严重威胁婴幼儿生命及视力的眼内恶性肿瘤。因此对RB的研究引起了广大医     

三维超声在眼科的应用

三维超声成像技术是一种新兴的医学影像技术，可对组织结构的所有信息进行重建，具有灰阶特征，可显示解剖细节，是目前最具临床使用价值的新技术。三维超声成像技术可应用于对各种眼内疾病，包括眼内肿瘤、玻璃体出血、视网膜脱离、虹膜睫状体疾患等的诊断。通过先进的三维超声技术，还可以精确的测量出眼内肿瘤体积的人小，以指导治疗。     

眼内液检测在急性视网膜坏死预后评估中的作用

急性视网膜坏死(ARN)是由疱疹病毒引起的罕见且严重的葡萄膜炎, 多由水痘-带状疱疹病毒(VZV)及单纯疱疹病毒(HSV)导致, 主要表现为玻璃体炎、闭塞性视网膜动脉炎及视网膜坏死, 视网膜脱离是其常见晚期并发症[1]。眼内液中检测到病毒核酸是ARN诊断的直接证据。近年来, 眼内液检测在感染性眼病中的作用得到重视, 对多种感染性葡萄膜炎的诊断、治疗有指导甚至是决定性作用[2-4]。为进一步了解眼内液检测在评估ARN视力预后中的作用, 我们对一组ARN患眼房水检测结果与视力预后相关性进行了分析。现将结果报道如下。     

感染性眼内炎研究现状及进展

感染性眼内炎是由各种病原体进入眼内导致的 眼内感染和炎症反应，视感染源的不同分为外源性和内源性眼内炎。外源性眼内炎多由外伤 和眼内手术引起，其致病菌分别以混合感染和革兰阳性菌为主；内源性眼内炎主要是由 身体其他部位感染延移引起，致病菌以真菌感染为主。眼内液的微生物检查是确诊眼内炎的 可靠方法，聚合酶链式反应在证实病源微生物感染方面有较高阳性率。及时有效的药物是成 功治疗眼内炎的关键，玻璃体视网膜手术是治疗严重眼内炎的有效手段。     

曲安奈德眼内注射的并发症不容忽视

眼内注射曲安奈德治疗由糖尿病视网膜病变、葡萄膜炎、渗出型老年黄斑变性或视网膜静脉阻塞等引起的黄斑水肿、慢性低眼压等疾病的有效性已得到公认，其临床应用日趋普遍，在充分肯定其治疗作用的同时，曲安奈德的副作用及并发症——继发性青光眼、并发性白内障、眼内炎、视网膜脱离及玻璃体积血等这些已经报道的及尚未认识到的并发症必须引起临床医师的高度警惕及重视。     

Stray light of spectacle lenses compared with stray light in the eye.

Stray light in spectacle lenses may affect the overall vision. It may also affect the measurement of ocular stray light, contrast sensitivity, or glare sensitivity. This article describes common stray light characteristics for glass and plastic spectacle lenses and compares this to the stray light characteristics of the eye, which are well known from the literature. Stray light is described by the skirts of the point-spread function (PSF), which were measured for angles from 4 degrees to 30 degrees. The PSF of spectacle lenses appears to follow the equation PSF = a(10). (theta/10)b, with a(10) and b representing fitting parameters and theta representing the stray light angle. The slope b is on average -2, which similar to that of the eye. For clean spectacle lenses, the PSF is usually at least an order of magnitude lower than that of the eye, whereas "as worn" (uncleaned) spectacle lenses may approach the PSF of the eye. To reach the PSF of the eye, the spectacle lens needs to be contaminated by as much as one or two fingerprints. The article also shows that plastic spectacle lenses degrade much faster than glass spectacle lenses when looking at the amount of stray light.     

飞秒激光角膜原位磨镶术手术前后散射变化及其影响因素分析

背景准分子激光角膜原位磨镶术（LASIK）是近年来新兴的屈光手术方式，其术后的视觉质量越来越受到关注。散射光是一项评价视觉质量的重要指标，近年来不同屈光手术前后散射光变化及其影响因素的研究是一个热点问题，研究飞秒LASIK手术后散射光的变化对术后视觉质量的评价具有重要意义。目的观察飞秒LASIK手术前后散射光的变化，并对其影响因素进行分析。方法回顾性分析2010年12月至2011年2月在天津市眼科医院行飞秒LASIK的近视及近视散光患者55例109眼的临床资料，对患者术前，术后1d、1周、1个月和6个月应用C—Quant散射光计量仪测量的散射光计量值变化进行分析，并分析各时间点散射光计量值变化与术前年龄、等效球镜度、瞳孔大小和中央角膜厚度（CCT）的关系，分析术后各时间点散射光计量值变化与残余角膜植床厚度（RBT）、RBT／CCT、切削深度、切削比、设定瓣厚度、角膜瓣直径、蒂宽、能量之间的关系。结果飞秒LASIK术前，术后1d、1周、1个月和6个月测得的散射光计量值分别为0．90_＋0．19、1．10-＋0．19、1．02_＋0．18、0．96±0．16和0．94±0．15，各时间点间所测散射光计量值的总体比较差异有统计学意义（F=17．699，P=0．000），术后1周的散射光计量值明显高于术后6个月，差异有统计学意义（t=2．412，P=0．017），术后1个月与术后6个月术眼的散射光计量值差异无统计学意义（t=0．779，P=0．437），术前和术后6个月散射光计量值差异无统计学意义（t=-1．877，P=0．062）。术前散射光计量值与年龄、等效球镜度、瞳孔大小和CCT均无明显相关性（P〉0．05）；术后1周、1个月及6个月散射光计量值变化与切削深度均呈负相关（r=0．226、-0．228、-0．241，P〈O．05），与切削比均呈负相关（，=-0．149、-0．219、-0．255，P〈0．05）。结论飞秒LASIK术后1个月内散射光计量值增加，术后6个月恢复正常。术后散射光计量值的变化可能与手术中选择的多种参数和因素有关。     

Measurement of stray light and glare: comparison of Nyktotest, Mesotest, stray light meter, and computer implemented stray light meter

AIM: To evaluate the properties of devices for measuring stray light and glare: the Nyktotest, Mesotest, "conventional" stray light meter and a new, computer implemented version of the stray light meter. METHODS: 112 subjects, divided in three groups: (1) young subjects without any eye disease; (2) elderly subjects without any eye disease, and (3) subjects with (early) cataract in at least one eye. All subjects underwent a battery of glare and stray light tests, measurement of visual acuity, contrast sensitivity, refraction, and LOCS III cataract classification. Subjects answered a questionnaire on perceived disability during driving. RESULTS: Repeatability values were similar for all glare/stray light tests. Validity (correlation with LOCS III and questionnaire scores), discriminative ability (ability to discriminate between the three groups), and added value (to measurement of visual acuity and contrast sensitivity) were all superior for both stray light meters. Results of successive measurements are interrelated for the conventional but not the new stray light meter. This indicates a better resistance to fraud for the latter device. CONCLUSIONS: The new computer implemented stray light meter is the most promising device for future stray light measurements.     

Factors affecting light scatter in contact lens wearers

We measured forward light scatter at 3.5, 10, and 28 degrees using a portable stray light meter. Subjects included 66 normal subjects (age range 19 to 79 years), 17 established hydrophilic contact lens wearers, and 15 rigid gas permeable (RGP) contact lens wearers. Contact lens deposits were measured using a modified Rudko procedure and a Leitz/Wild Makroscope M240. Corneal health was assessed using slitlamp biomicroscopy. Results showed a significant increase in light scatter with age, particularly after the age of 40 years. Stray light scores were significantly lower in pigmented non-Caucasian subjects, particularly at larger angles. The stray light scores were significantly greater in contact lens wearers than in age-matched normals, but were not found to correlate with the amount of lens deposits. Scores from hydrophilic lens wearers after removal of their lenses were significantly higher than results from RGP wearers after removal of their lenses and from age-matched normals. This suggests the presence of subclinical corneal edema in some of these subjects.     

The effect of lens opacities on the visual field (author's transl)

The stray light effect on the visual field was quantitatively studied in normal subjects under experimental conditions. Stray light comparable to that caused by lens opacities was produced by means of selective occluders or diascleral illumination. The results derived from this model were compared with the statistical evaluation of the visual fields of 123 eyes with glaucoma followed for a minimum of 10 years. As expected lens opacities resulted in a concentric constriction of the peripheral fields and a loss of the inner isopters. The light difference sensitivity as determined by static perimetry was generally reduced preferentially in the central fields. These calculations provide a measure to anticipate the degree of lens opacifications from a depressed visual without knowledge of the visual acuity.     

Einfluss verschiedener multifokaler Intraokularlinsenkonzepte auf den Streulichtparameter

Purpose

Multifocal intraocular lenses (MIOL) are known to induce various photic phenomena depending on the optical principle. The aim of this study was to investigate the correlation between stray light measurements performed with the C-Quant (Oculus, Germany) and the results of a subjective patient questionnaire.

Patients and methods

In this study three different MIOLs were compared: AMO ReZoom (refractive design, n=10), AMO ZM900 (diffractive design, n=10) and Oculentis Mplus (near segment design, n=10). Cataract and refractive patients were enrolled in the study. Functional results were evaluated at least 3 months postoperatively followed by stray light measurements and a subjective questionnaire.

Results

Surgery was performed for all patients without complications. The three groups were matched for age, IOL power and corrected distance visual acuity (CDVA). Significantly different stray light (median) values log(s) were found (Kruskal-Wallis test, p<0.05): 1.12 log (refractive), 1.13 log (segment) and 1.28 log (diffractive). The subjective questionnaire did not show differences in glare perception but refractive MIOL patients noticed more halos surrounding light sources than the diffractive and segment MIOL patients.

Conclusions

Stray light and subjective photopic phenomena do not show any basic correlation. Measurements in patients with refractive MIOLs showed less stray light than near segment or diffractive MIOLs. However, refractive MIOLs induced more halos compared to the other groups analyzed.     

Effect of corneal light scatter on vision: a review of the literature

The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it.     

Dynamic range and stray light

The role of intraocular stray light upon contrast threshold of two skilled human observers was studied by perimetric methods using the automatic perimeter Octopus. Stray light falsifies the contrast sensitivity profile of the blind spot when a critical test stimulus luminance, which differs for various targets, is exceeded. At still higher luminance levels, because stray light effects increase, the blind spot shrinks and finally disappears. A series of high resolution measurements of the blind spot with the automatic perimeter Octopus provide a quantitative answer concerning the commencement and amount of this disturbance as a function of target size and target luminance. The amount of stray light, when using targets varying from 0 to 5 (Goldmann standard) is related to luminous power (target luminance x target area). Using first order assumptions about the stray light emitting characteristics of the disc and empirical data, one may conclude that an increase in luminance of target 0 from 10³ to 10⁵ asb only increases the effective dynamic range by about 2 dB (= 0.2 log units 3, the standard target as compared with target) size used in Octopus perimetry, at a luminance level of 10³ asb. Falsification of sensitivity gradients and underestimates of depths of scotomata due to stray light effects may be an ever present danger in perimetric determinations. The useful dynamic range in perimetry appears to be limited by photon noise and noise in the neurovisual system on the one hand and by stray light interference on the other.Abbrevations and Symbols 1 asb 0.318 cd/m² apostilb, luminance unit - 1 dB 0.1 log units, used in log scale for target luminances see fig, 7, T = 0/T = 5 - A (deg²) target area, measured on cupola - A₁ (deg²) area of blind spot at level L₁ - A_u (deg²) area of blind spot at level L_u - B (dB) contrast sensitivity (c.s.) marking bottom of blind spot - B* (dB) same as B, obtained from model in appendix 1 - c.s. (dB) contrast sensitivity: attenuation of threshold target luminance below 1000 asb (MAX) - DRØ (dB) U-MAX total dynamic range - DR1 (dB) U-B useful dynamic range including stray light interference - DR1* (dB) U-B* same as DR1, obtained from model in appendix 1 - DR2 (dB) U-K dynamic range uncontaminated by stray light - DR2* (dB) U-K* same as DR2, obtained from model in appendix 1 - K (dB) critical c.s. marking begin of stray light interference - L (asb) target luminance, measured on cupola - L_B (asb) target luminance corresponding to B - L_k (asb) critical target luminance corresponding to K - L₁ (asb) lower test level in adaptive program - L_MAX (asb) maximum target luminance of the system corresp. to MAX - L_U (asb) average target luminance corresponding to U - L_U (asb) upper test level in adaptive program - L_u (asb) illuminance of the retina surrounding blind spot by stray light - MAX (dB) minimum c.s. (=0 dB) corresponding to L_MAX - P (erg/sec) luminous power - R (deg) average radius of blind spot taking stray light effects into account - R₁ (deg) average radius of blind spot at level L₁ - R_t (deg) average radius of blind spot uncontaminated by stray light effects - R_u (deg) average radius of blind spot at level L_u - S (dB) same as c.s. - t tangent - T (G.S.) target size, Goldmann standards - U (dB) average c.s. surrounding blind spot - factor, increase of background luminance - factor, indicating change of L_u due to - ' factor, indicating change of L_x due to in order that stray light effects remain at threshold - R (deg) reduction of radius of blind spot due to stray light interference - R/R_t relative decrease of radius of blind spot due to stray light interference     

年龄相关性白内障患者术后视觉功能的评价

晶状体的混浊可造成光线散射,导致视网膜成像的对比度和清晰度下降,影响白内障患者的正常工作和生活。进行白内障手术后,部分患者虽然视力检查良好,但仍反映视觉质量很差。寻求一种能够相对客观地反映屈光介质和视网膜成像的检测系统来评价视觉质量显得尤为重要。目前临床上常用的方法为对比敏感度（CS）检查和视觉问卷调查,通过测量CS可以判断白内障患者视觉质量和生活质量下降的程度,且对白内障术后疗效的评价有重要价值。通过文献回顾,就年龄相关性白内障患者术前及术后CS特征的研究进展进行综休。