NOD小鼠视网膜VEGF表达和视网膜细胞凋亡

目的:研究NOD小鼠早期糖尿病视网膜VEGF表达和视网膜细胞凋亡情况,以及二者间的关系。方法:NOD小鼠分为对照组(非糖尿病小鼠)(2,4,6,8,12wk组,n=30)和糖尿病组(2,4,6,8,12wk组,n=30)。每组小鼠在规定时间处死,提取血液标本,摘除眼球,分离视网膜备用。ELISA法检测视网膜VEGF和血液VEGF。透射电子显微镜检测小鼠视网膜细胞凋亡情况。结果:糖尿病组血液和视网膜VEGF表达与对照组相比明显增高(12wk,血液标本:4.9±0.4μg/gvs0.19±0.1μg/g,P<0.01;视网膜,165.0±9.0μg/gvs18.0±4.0μg/g,P<0.01)。NOD小鼠早期糖尿病视网膜VEGF表达和血液VEGF表达呈正相关(γ=0.9902,P=0.001)。糖尿病组视网膜神经节细胞和血管内皮细胞凋亡明显增加P<0.01。结论:视网膜VEGF表达增加可能与视网膜凋亡增多有关。早期糖尿病NOD小鼠视网膜VEGF表达增加是多因素的。     

早期糖尿病NOD小鼠视网膜HIF-1的表达

目的:探讨糖尿病NOD小鼠视网膜HIF-1α的表达。方法:NOD小鼠随机分为正常对照组和糖尿病组,分别于糖尿病2、4、6、8和12周处死正常对照组和糖尿病组小鼠,摘除眼球后分离视网膜。Westernblot方法检测视网膜HIF-1α的表达,免疫组化方法检测视网膜上HIF-1α的表达。结果:与正常对照组相比,糖尿病组小鼠血糖明显增高,体重明显下降(P<0.01);Westernblot显示糖尿病6周时视网膜HIF-1α低水平表达,12周时HIF-1α表达增高;免疫组化显示糖尿病组12周时视网膜内层HIF-1α表达增加,而未见视网膜外层HIF-1α表达。结论:糖尿病早期视网膜HIF-1α表达增高,说明在糖尿病早期视网膜发生缺血缺氧;HIF-1α可能参与了糖尿病早期视网膜缺血缺氧的继发损害过程。     

非肥胖性糖尿病小鼠的早期视网膜病变

目的:研究早期糖尿病视网膜病变的小鼠模型。方法:NOD小鼠随机分为正常对照组(4,12wk组,n=8)和糖尿病组(4,12wk组,n=12),每组取4wk和12wk处死小鼠,光镜和电镜观察视网膜结构的改变。结果:糖尿病组4wk时毛细血管基底膜增厚,可见内皮细胞、周细胞和神经节细胞超微结构改变。12wk时基底膜明显增厚,内皮细胞、周细胞和神经节细胞凋亡增加。结论:在糖尿病早期发生了视网膜神经元细胞超微结构病变和微血管病变。     

早期糖尿病大鼠视网膜形态变化及相关影响因子分析

背景糖尿病视网膜病变（DR）的病理基础是血-视网膜屏障受损,是多种因子共同影响的结果。目的探讨早期糖尿病大鼠视网膜形态变化与血清中血管内皮生长因子（VEGF）、内皮素（ET）和一氧化氮（NO）的关系。方法40只健康雌性SD大鼠按随机数字表法分为实验组和正常对照组,每组20只。实验组腹腔注射60mg／kg链脲佐菌素（STZ）建模成功后,按病程分为糖尿病2、4、6、8个月组;正常对照组腹腔注射等体积缓冲液,根据与实验组年龄匹配原则平均分为4组,每组5只。分别在造模后2、4、6、8个月采用ELISA双抗体夹心法测定2组大鼠血清中VEGF质量浓度,^125碘（^125I）放射免疫法测定血清中ET质量浓度,硝酸还原法测定血清中NO浓度并进行比较。于造模后8个月摘除大鼠眼球行常规视网膜组织形态学检查。结果正常对照组大鼠在实验各时间点视网膜组织形态学无明显改变。实验组大鼠造模后4个月开始出现视网膜组织水肿,视网膜各层细胞排列紊乱,造模后6个月可见视网膜出血,造模后8个月可见视网膜血管破裂。实验组大鼠在造模后2、4、6、8个月血清中VEGF和ET质量浓度较同时间点正常对照组大鼠明显升高,差异均有统计学意义（P〈0．05）,糖尿病2个月组血清中NO浓度较同时间点正常对照组升高（Z=-2．193,P〈0．05）,糖尿病4个月组与正常对照组比较,血清中NO浓度的差异无统计学意义（Z=-2．611,P〉0．05）,而糖尿病6个月组及糖尿病8个月组血清NO浓度较同时间点正常对照组低（Z=-2．449、-2．236,P〈0．05）。随着病程的延长,实验组血清中VEGF、ET质量浓度逐渐升高,NO浓度逐渐降低（P〈0．05）。糖尿病大鼠血清中VEGF与ET质量浓度间呈正相关（r=0．821,P〈0．01）,血清中VEGF质量浓度与NO浓度间呈负相关（r=-0．814,P〈0．01）;糖尿病大鼠血清中ET质量浓度与NO浓度间呈负相关（r=-0．803,P〈0．01）。结论糖尿病大鼠血清中VEGF、ET和NO水平与视网膜病理改变的严重程度密切相关,考虑血清中VEGF、ET与NO水平可以间接反映糖尿病大鼠视网膜病变的严重程度。     

塞来昔布对糖尿病大鼠视网膜血管内皮生长因子表达的影响

目的 观察塞来昔布对糖尿病大鼠视网膜血管内皮生长因子（VEGF）表达的影响。 方法 将36只大鼠用链脲佐菌素（STZ）腹腔注射制成糖尿病大鼠模型，随机分成糖尿病组(n=18)和塞来昔布灌胃组(n=18)。塞来昔布灌胃组大鼠经口灌胃塞来昔布50 mg/kg；糖尿病组经口灌胃等体积生理盐水。另18只正常大鼠为正常对照组。3个月后处死全部大鼠，应用免疫组织化学技术检测视网膜VEGF蛋白表达，逆转录多聚酶链式反应（RT-PCR）方法检测视网膜VEGF-mRNA和环氧化酶(COX)-2-mRNA的表达。 结果 正常对照组视网膜VEGF-mRNA和COX-2-mRNA表达量少，VEGF免疫组织化学反应弱阳性，VEGF蛋白表达量低；糖尿病组较正常对照组视网膜VEGF-mRNA和COX-2-mRNA表达均上调(P＜0.05)，VEGF免疫组织化学反应呈强阳性，VEGF蛋白表达增高(P＜0.01)；塞来昔布灌胃组较糖尿病组视网膜VEGF mRNA表达显著下降(P＜0.05)，COX-2- mRNA的表达无显著降低(P>0.05)，VEGF免疫组织化学反应阳性减弱，VEGF蛋白表达降低(P＜0.01)。 结论 塞来昔布可通过抑制COX-2的活性进一步抑制STZ诱导的糖尿病大鼠视网膜VEGF-mRNA及蛋白表达。(中华眼底病杂志,2007,23:265-268)     

巴曲酶对糖尿病大鼠血视网膜屏障和视网膜血管内皮生长因子表达的影响

目的 研究巴曲酶对糖尿病大鼠血视网膜屏障以及视网膜血管内皮生长因子（VEGF）表达的影响。 方法 将60只大鼠用链尿佐菌素腹腔注射制成糖尿病大鼠模型，分成糖尿病组（n＝20）、40mg/kg巴曲酶注射组（n＝20）和20 mg/kg巴曲酶注射组（n＝20）。另25只正常大鼠为正常对照组。7d 后处死全部大鼠，通过伊凡思蓝法观察各组大鼠血视网膜屏障情况，酶连免疫吸附法分析视网膜总蛋白中的VEGF含量，比较各组结果。 结果 正常对照组大鼠视网膜内渗漏的伊凡思蓝含量明显低于另外3个糖尿病大鼠组（P<0.01）,不同剂量巴曲酶治疗组之间伊凡思蓝含量无明显差异（P>0.05），巴曲酶治疗的2组大鼠伊凡思蓝含量均比糖尿病组大鼠低（P<0.05）。正常对照组大鼠、不同剂量巴曲酶注射的2组大鼠视网膜内VEGF含量明显低于糖尿病大鼠（P<0.01）；正常对照组视网膜内VEGF含量与20 mg/kg巴曲酶注射组比较无明显差异（P＝0.06）；40mg/kg 巴曲酶注射组视网膜内VEGF含量比正常对照组低(P＝0.01)；不同剂量的巴曲酶治疗组之间VEGF含量无明显差异（P＝0.78）。 结论 巴曲酶治疗减轻了糖尿病大鼠血视网膜屏障功能的损伤，降低了VEGF的表达，提示巴曲酶对糖尿病大鼠血视网膜屏障功能有一定的保护作用。 (中华眼底病杂志, 2006, 22: 16-19)     

糖尿病小鼠视网膜中JNK3 mRNA表达的动态变化

背景 糖尿病视网膜病变（DR）是糖尿病常见的眼部并发症,其发病机制与多种因素有关,c-jun N末端激酶（JNK）作为一种凋亡基因,在糖尿病的病理过程中发挥着重要作用,其研究已成为近些年的热点之一,而JNK3作为JNK的亚基因之一,在DR中的研究目前较少.目的 定量检测JNK3在糖尿病小鼠视网膜中的表达,探讨JNK3在DR中的作用.方法 选取SPF级6～8周龄C57BL/6雄性小鼠48只,适应性喂养1周后按照随机数字表法分为糖尿病组和正常对照组.30只糖尿病组小鼠用一次性腹腔内注射柠檬酸钠缓冲液溶解的质量分数1％链脲佐菌素（STZ）的方法诱导糖尿病模型,18只对照组小鼠腹腔内注射等容量柠檬酸钠缓冲液.分别于造模后2、4、8周摘除小鼠左眼眼球,提取视网膜组织,采用实时定量PCR法检测JNK3 mRNA在小鼠视网膜中表达的动态变化.结果 造模后2、4、8周,糖尿病组小鼠血糖水平明显高于正常对照组,差异均有统计学意义（t=-5.675、-5.498、-5.347,P＜0.01）.糖尿病组和正常对照组在造模后不同时间点小鼠视网膜中JNK3 mRNA相对表达量（A值）的差异均有统计学意义（F分组=102.345,P＜0.05;F时间 =131.679,P＜0.05）;其中造模后4周和8周糖尿病组小鼠视网膜中JNK3 mRNA相对表达量分别为3.21±0.14和5.43±0.37,均明显高于正常对照组的2.54 ±0.42和2.26±0.67,差异均有统计学意义（t=4.073、23.399,P＜0.05）;糖尿病组内比较可见,造模后8周小鼠视网膜中JNK3 mRNA相对表达量明显高于2周和4周值,差异均有统计学意义（t=10.756、16.857,P＜0.05）.结论 JNK3在糖尿病小鼠视网膜中表达量上调,其早期表达量随时间延长而增加.JNK3可能参与早期DR的发生和发展.     

VEGF siRNA抑制鼠视网膜新生血管的实验研究

背景血管内皮生长因子（VEGF）在视网膜新生血管的发生过程中发挥重要作用,抑制VEGF是目前视网膜新生血管治疗和预防研究的热点。VEGF小片段干扰RNA（VEGFsiRNA）在抗肿瘤新生血管的研究中已经取得了显著疗效,但对于视网膜新生血管的干预作用报道较少。目的研究VEGF siRNA对鼠视网膜新生血管的抑制作用。方法48只新生C57BL／6J幼鼠采用随机数字表法随机分为正常对照组、模型对照组、空载体组和VEGF siRNA质粒转染组,每组12只幼鼠。7日龄C57BL／6J幼鼠36只及其母鼠置于密闭的氧舱5d建立缺氧性新生血管模型,其中12只幼鼠不进行质粒转染作为模型对照组,其余24只鼠玻璃体腔内注射脂质体（LF2000）包裹的空载体质粒或VEGF siRNA表达质粒。待小鼠19日龄时获取小鼠眼球并分离视网膜,用苏木精一伊红染色法计数各组小鼠视网膜新生血管内皮细胞核的数目,用实时荧光定量聚合酶链反应（tea-time PCR）法检测视网膜中VEGF mRNA的表达,并应用免疫荧光技术检测小鼠视网膜中VEGF蛋白的表达。结果正常对照组、模型对照组、空载体组和VEGFsiRNA质粒转染组19日龄小鼠视网膜突破内界膜的内皮细胞细胞核数目分别为（0．19±0．09）个、（24．89±2．03）个、（23．65±2．15）个和（8．83±1．12）个,表明VEGFsiRNA质粒转染组小鼠的新生血管内皮细胞数明显低于模型对照组和空载体组,差异均有统计学意义（q=5．67、q=4．97,P〈0．01）。Real-time PCR检测表明,正常对照组小鼠视网膜中仅见弱的VEGF mRNA表达,而模型对照组与空载体组VEGF mRNA表达量为正常对照组的52．3倍和36．7倍,VEGF siRNA质粒转染组小鼠视网膜VEGF mRNA的表达量为正常对照组的3．5倍,明显低于模型对照组与空载体组。VEGF siRNA对VEGF mRNA的抑制率为43．39％。免疫荧光染色显示,正常对照组小鼠VEGF蛋白呈弱阳性表达,模型对照组和空载体组VEGF小鼠视网膜中VEGF蛋白表达呈强阳性,VEGF siRNA质粒转染组VEGF蛋白表达明显减弱。结论玻璃体腔注射VEGF siRNA表达质粒可有效抑制C57BL／6J小鼠氧诱导视网膜病变模型新生血管的形成。     

葛花总黄酮对糖尿病小鼠视网膜形态学改变及 VEGF表达的影响

目的：探讨葛花总黄酮（ TFF）对糖尿病小鼠视网膜形态学改变及血管内皮生长因子（ VEGF）表达的影响。方法40只C57BL／6J小鼠随机分为5组：正常对照组、糖尿病模型组、葛花总黄酮小剂量组（ TFFⅠ）、中剂量组（ TFFⅡ）和大剂量组（ TFFⅢ）。糖尿病模型组和药物干预组小鼠腹腔注射链脲霉素（ STZ）建立I型糖尿病模型。 STZ诱导后第5周开始给药,第15周处死小鼠取眼球,采用苏木素-伊红（ HE）染色观察小鼠视网膜组织的形态学改变;免疫组织化学染色法检测视网膜VEGF的表达。结果葛花总黄酮小、中剂量组视网膜厚度稍变薄,毛细血管基底膜增厚不明显,神经节细胞稍减少,神经纤维层可见少量空泡样变性,内核层与外核层细胞排列基本整齐;葛花总黄酮大剂量组各层细胞排列整齐,视网膜厚度基本正常,神经节细胞稍减少,神经纤维层未见空泡样变性,内、外核层细胞排列整齐。给予葛花总黄酮治疗组VEGF免疫阳性产物表达较模型组减弱。葛花总黄酮小、中、大剂量组VEGF免疫组化阳性产物平均光密度值（分别为：35．53±3．12、25．42±3．60、16．43±4．89）与糖尿病模型组（55．54±8．87）比较差异有统计学意义（ P ＜0.01）。结论 VEGF在糖尿病视网膜病变的发生发展中起重要作用,葛花总黄酮可改善糖尿病视网膜病变小鼠视网膜的病理形态,并可通过下调VEGF的表达,发挥对糖尿病视网膜病变的保护作用。     

臭氧对STZ诱导的糖尿病大鼠视网膜表达VEGF, HIF-1α与PEDF的影响

目的：通过测定经臭氧灌肠治疗后的糖尿病大鼠视网膜及血清中血管内皮生长因子（ VEGF ）、缺氧诱导因子－1α（ HIF－1α）与色素上皮衍生因子（ PEDF）的表达差异,了解臭氧在早期糖尿病视网膜病变治疗的作用。方法：选取70只雄性SD大鼠中的10只做为正常对照组,予以正常饮食;余大鼠经适应性喂养后通过腹腔一次性注射链脲佐菌素（50mg／ml）制作糖尿病模型。将造模成功的大鼠模型随机分成模型对照组（B组）、氧气治疗组（C组）及臭氧治疗组（D组）,其中臭氧治疗组给予臭氧灌肠治疗（2次／wk,共计1mo）,氧气治疗组给予同等剂量及频次的氧气进行灌肠治疗,治疗1mo 后取视网膜及血清,使用免疫组化法检测视网膜中 VEGF 的表达,使用ELISA及RT－PCR的方法检测视网膜及血清中 VEGF、HIF－1α与PEDF的含量。结果：免疫组化结果显示VEGF主要在内层视网膜表达,而臭氧治疗组VEGF表达接近于空白对照组;血清与视网膜中VEGFmRNA 表达在四组间均有统计学差异（F ＝23．923;P＝0．000）,其中臭氧治疗组VEGF的表达接近于空白对照组,但差异仍有统计学意义（P＜0．05）;而模型对照组同氧气治疗组的 VEGF 表达亦无统计学差异（ P＞0．05）;相对于空白对照组,臭氧治疗组HIF－1α表达下降（P＜0．05）,而在模型对照组与氧气治疗组间无统计学差异（ P＞0．05）。 PEDFmRNA在四组间的表达均有差异,但差异均无统计学意义（P＞0．05）。结论：臭氧灌肠治疗可以有效的降低血清及视网膜中VEGF和HIF－1α的表达,可以一定程度的抑制早期糖尿病视网膜病变的发展。     

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye-hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye-hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.     

Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: Evaluation and management

Paraneoplastic syndromes involving the visual system are a heterogeneous group of disorders occurring in the setting of systemic malignancy. Timely recognition of one of these entities can facilitate early detection and treatment of an unsuspected, underlying malignancy, sometimes months before it would have otherwise presented, and gives the patient an increased chance at survival. We outline the clinical features, pathogenesis, and treatment strategies for the retinal- and optic nerve–based paraneoplastic syndromes: cancer-associated retinopathy; melanoma-associated retinopathy; paraneoplastic vitelliform maculopathy; bilateral diffuse uveal melanocytic proliferation; paraneoplastic optic neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome. Distinguishing these disorders from their non-paraneoplastic counterparts (e.g., autoimmune-related retinopathy and optic neuropathy, and acute zonal occult outer retinopathy) and determining appropriate systemic evaluation for the responsible tumor can be challenging. In addition, we discuss the utility and interpretation of autoantibody testing.     

Sensitivity to first- and second-order motion and form in children and adults

We compared the sensitivity of adults and children aged 3-10 years to first- and second-order motion and form. For first-order stimuli, at all ages sensitivity was better for motion than form, and motion thresholds were better at 6 Hz than at 1.5 Hz. For second-order stimuli, at all ages sensitivity was better for form than motion, and motion thresholds were better at 0.25 cyc/deg than at 1 cyc/deg. Thresholds became adult-like later for motion than for form and later for first-order than second-order stimuli. For first-order stimuli, the changes with age were larger and more protracted.     

Nodes and nodal points and lines in eyes and other optical systems

The typical stigmatic optical system has two nodal points: an incident nodal point and an emergent nodal point. A ray through the incident nodal point emerges from the system through the emergent nodal point with its direction unchanged. In the presence of astigmatism nodal points are not possible in most cases. Instead there are structures, called nodes in this paper, of which nodal points are special cases. Because of astigmatism most eyes do not have nodal points a fact with obvious implications for concepts, such as the visual axis, which are based on nodal points. In order to gain insight into the issues this paper develops a general theory of nodes which holds for optical systems in general, including eyes, and makes particular allowance for astigmatism and relative decentration of refracting elements in the system. Key concepts are the incident and emergent nodal characteristics of the optical system. They are represented by 2 × 2 matrices whose eigenstructures define the nature and longitudinal position of the nodes. If a system's nodal characteristic is a scalar matrix then the node is a nodal point. Otherwise there are several possibilities: Firstly, a node may take the form of a single nodal line. Second, a node may consist of two separated nodal lines reminiscent of the familiar interval of Sturm although the nodal lines are not necessarily orthogonal. Third, a node may have no obvious nodal line or point. In the second and third of these classes one can define mid-nodal ellipses. Astigmatic systems exist with nodal points and stigmatic systems exist with no nodal points. The nodal centre may serve as an approximation for a nodal point if the node is not a point. Examples in the Appendix , including a model eye, illustrate the several possibilities.     

Nutritional antioxidants and age-related cataract and maculopathy

Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that the same nutritional practices that are associated with prolonged eye function will also be associated with delayed age-related compromises to other organs, and perhaps, aging in general, (2) surgical resources are insufficient to provide economic and safe surgeries for cataract and do not provide a cure for ARM, and (3) there will be considerable financial savings and improvements in quality of life if health rather than old age is extended, particularly given the rapidly growing elderly segment of our population. It is clear that oxidative stress is associated with compromises to the lens and retina. Recent literature indicates that antioxidants may ameliorate the risk for ARC and ARM. Given the association between oxidative damage and age-related eye debilities, it is not surprising that over 70 studies have attempted to relate antioxidant intake to risk for ARC and ARM. This article will review epidemiological literature about ARC and ARM with emphasis on roles for vitamins C and E and carotenoids. Since glycation and glycoxidation are major molecular insults which involve an oxidative stress component, we also review new literature that relates dietary carbohydrate intake to risk for ARC and ARM. To evaluate dietary effects as a whole, several studies have tried to relate dietary patterns to risk for ARC. We will also give some attention to this emerging research. While data from the observational studies generally support a protective role for antioxidants in foods or supplements, results from intervention trials are less encouraging with respect to limiting risk for ARC/ARM prevalence or progress through antioxidant supplementations, or maintaining higher levels of antioxidants either in diet or blood. Without more information it is difficult to parse these results. It would be worthwhile to determine why the various types of studies are not yielding similar results. However, there are many common insults and mechanistic compromises that are associated with aging, and proper nutrition early in life may address some of these compromises and provide for extended youthful function later in life. Indeed, proper nutrition, possibly including use of antioxidant supplements for the nutritionally impoverished, along with healthy life styles may provide the least costly and most practical means to delay ARC and ARM. Further studies should be devoted to identifying the most effective strategy to prevent or delay the development and progress of ARC/ARM. The efforts should include identifying the right nutrient(s), defining useful levels of the nutrient(s), and determining the age when the supplementation should begin.     

Ethics and optometry: concepts and applications

Ethics refers both to the study of behaviour, and moral principals. The related concepts of justice and law are also relevant to optometry. A profession typically claims specialist knowledge and ethical behaviour – putting the interests of clients above its own. However, professional codes fail as ethical directives, and their goals are questioned. Beginning with broad principles, institutional ethics and issues of general health care provision are considered, and applications to optometry are made. Ethical theory can guide us in interacting with our patients, utilising resources and ordering priorities. The conservative approach to consumerism and advertising is defended on the basis of protecting public and professional interests. Ethical behaviour can be fostered, and this process should begin in undergraduate education.     

Exogenous attention and color perception: performance and appearance of saturation and hue

Exogenous covert attention is an automatic, transient form of attention that can be triggered by sudden changes in the periphery. Here we test for the effects of attention on color perception. We used the methodology developed by Carrasco, Ling, and Read [Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7 (3) 308-313] to explore the effects of exogenous attention on appearance of saturation (Experiment 1) and of hue (Experiment 2). We also tested orientation discrimination performance for single stimuli defined by saturation or hue (Experiment 3). The results indicate that attention increases apparent saturation, but does not change apparent hue, notwithstanding the fact that it improves orientation discrimination for both saturation and hue stimuli.     

Aberration and contrast sensitivity comparison of aspherical and monofocal and multifocal intraocular lens eyes

BACKGROUND: Higher-order aberrations and contrast sensitivity were evaluated in patients who underwent phacoemulsification cataract extraction followed by implantation of aspherical, monofocal or multifocal intraocular lens (IOL) replacements. METHODS: In this comparative trial, 124 patients with an average age of 66.8+/-5.2 years and their 124 eyes were randomly divided into three surgical implantation groups to receive one of three types of IOLs in replacement of cataract lenses. The patients of group 1 were given an aspherical IOL Z9001 (AMO, Santa Ana, CA, USA) replacement, and group 2 was implanted a monofocal IOL SA60AT (Alcon, Fort Worth, TX, USA) and group 3 the multifocal IOL SA40N (AMO). Post-surgical best-corrected visual acuity, corneal aberrations, total ocular aberrations, pupil diameters, capsulorhexsis sizes and contrast sensitivity were measured and compared. RESULTS: There was no statistical difference for mean best-corrected visual acuity, pupil diameter, curvilinear capsulorhexis size and corneal aberration among the three groups. For the spherical aberration, fourth-order higher-order aberration and total ocular higher-order aberration, the SA40N group was higher than the SA60AT group and the SA60AT group was higher than the Z9001 group, and the differences between the three groups were statistically significant for these measurements. Contrast sensitivity was higher for the Z9001 group than the SA60AT group and the SA60AT group was higher than the SA40N group, and the difference was statistically significant in all the spatial frequencies of 3, 6, 12 and 18. CONCLUSIONS: Although the multifocal IOL can provide near vision, it can increase higher-order aberration and negatively influence contrast sensitivity. However, the aspherical IOL can reduce aberration and improve contrast sensitivity as compared with the monofocal IOL.