三亚市郊≥50岁人群低视力及盲流行病学调查

目的:调查海南省三亚市郊≥50岁人群中低视力及盲的发病率并分析其原因。方法:随机抽取28个抽样单位的≥50岁人群共2569例进行调查。对调查人员进行矫正视力、外眼、前房、晶状体、玻璃体及眼底检查。观察其低视力及盲的患病率,分析致盲的重要原因。结果:2569例中受检2206例,受检率85.87%,低视力和盲的患病率分别为3.85%和1.90%。致盲主要眼病依次为白内障、青光眼、角膜病、眼睑疾病及翼状胬肉。结论:白内障依然是低视力和盲的首要病因,但眼睑疾病及翼状胬肉致盲也不容忽视。     

合肥市区老年人眼病流行病学调查

目的调查合肥市区≥60岁老年人的致盲及低视力的眼病结构。方法分别对合肥市不同辖区街道≥60岁的老年人进行调查并建立档案,使用SNELLEN视力表观察其盲及低视力患病率及其主要原因。结果在实际受检4009人中有完整档案3788例,共7566只眼,(4例眼球萎缩,6只义眼)。盲及低视力患病率分别为1．14％,9．56％,其中单眼盲为5．71％。致盲的主要原因依次为:白内障、视网膜退行性变、青光眼、糖尿病视网膜病变、角膜病、视网膜血管性疾病、葡萄膜炎、人工晶体术后、眼外伤等。低视力原因依次为:视网膜退行性变、白内障、青光眼、人工晶体术后、糖尿病视网膜病变、视网膜血管性疾病、角膜病、葡萄膜炎、眼外伤等。结论随着我国防盲治盲工作的深入开展,老年人盲和低视力患病率明显下降致盲的主要疾病谱发生了变化。     

新疆库车县40岁以上维吾尔族农民盲和低视力流行病学调查

目的调查新疆库车县年龄≥40岁维吾尔族农民盲与低视力的患病率及主要致盲原因。方法采用整群随机抽样方法,按世界卫生组织盲目分类标准对随机抽取的新疆库车县2955名维吾尔族农民进行视力调查,对针孔镜下视力低于0.3者进行眼部检查并做主要致盲原因诊断。结果共录入3692人,实际受检2955人,受检率为80.0%。其中双盲患病率为2.1%,双眼低视力患病率为9.9%。60岁组双盲患病率是40岁组的13.5倍,差异有统计学意义(P<0.01);男性双盲患病率是女性的1.4倍,差异无统计学意义(P>0.05);文盲组双盲患病率是非文盲组的4.5倍,差异有统计学意义(P<0.01)。结论新疆库车县年龄≥40岁维吾尔族农民盲及低视力患病率高于国内部分地区,首要致盲眼病仍为白内障,故降低白内障患病率是该地区防盲治盲的关键。     

安阳县40岁以上农民白内障筛查及治疗

目的了解安阳县≥40岁自觉视力障碍的农民盲与低视力的患病率及致盲原因。方法安阳县各行政村中,≥40岁自觉视力障碍的农民为筛查对象。采用WHO盲与低视力标准和白内障诊断标准。由眼科医生作眼部检查。对所有视力<0.3的患眼进行主要病因诊断,确诊所有白内障患者,并筛选出需手术治疗者。结果共检查853例,盲目患者23例,患病率2.70%,低视力患者99例,患病率4.27%,致盲的主要眼病依次为白内障、角膜病、青光眼、视网膜病等。共筛查出533例白内障,行白内障手术治疗301人次,脱残率98%,脱盲率99.34%。结论白内障仍是盲和低视力的首要病因,防盲治盲的重点仍是白内障复明手术。     

上海市北新泾街道老年人低视力和盲的流行病学调查

目的 调查上海市北新泾街道≥60岁老年人的低视力,盲患病率及致盲原因。方法 分别对1994,1997及2000年上海市北新泾街道所有≥60岁老年人进行调查,并建立视力档案,使用针孔镜矫正视力,观察其低视力及盲的患病率,分析致盲的主要原因。结果 1994,1997及2000年的实际受检率分别为83.87%,88.32%及91.98%;各年度低视力和盲的患病率分别为3.61%和1.51%,2.31%和1.09%及1.31%和0.71%。致盲的主要原因依次为视网膜退行性变,白内障,角膜病及视网膜血管性疾病。结论 1994,1997及2000年该地区盲的患病率及低视力率呈下降趋势,首位致盲原因为视网膜退行性变。     

甘肃省平凉市崆峒区人群盲和低视力现况调查

目的:探讨与了解甘肃省平凉市崆峒区人群盲与低视力的患病率及致病原因。方法:应用横断面研究的流行病学调查方法,以村(社区)为基础,采用随机整群抽样原则抽取6个乡镇2个街道办事处作为调查地点。采用世界卫生组织制定的盲与低视力标准,对全区按0.719%抽样比例抽取样本进行盲与低视力的流行病学调查。结果:检录3235例中,受检人数为2801例,受检率为86.58%,双眼盲21例,盲率为0.75%(男0.59%,女0.91%);双眼低视力125例,低视力患病率为4.46%(男3.73%,女5.16%),≥60岁以上盲与低视力患者的患病率明显增高。致盲病因前三位的眼病依次为白内障(47.62%)、角膜病(14.29%)、青光眼(14.29%)。结论:崆峒区人群中盲和低视力的眼病以白内障居首位,因此手术治疗白内障仍是今后防盲治盲工作的首要任务。     

广州市萝岗区盲与低视力流行病学调查

目的 调查广州市萝岗区年龄≥50岁人群盲与低视力的患病率及主要致病原因.方法 采用整群抽样方法 ,按世界卫生组织盲与低视力分类标准,对广州市萝岗区50岁及以上人群进行问卷调查,视力检测初筛后对针孔镜下视力低于0.3者,由眼科医师做视功能、眼前后节形态检查及主要致盲原闪诊断.结果 共录入人数4532人,实际受检4126人,受检率91.04%.其中双眼肓患病率为1.91%,单眼盲患病率5.96%,双眼低视力患病率8.41%.随着年龄增加,盲与低视力患病率明显升高.70岁年龄组双眼肓是50岁年龄组的25.5倍,差异具有统计学意义(P<0.01).在盲与低视力人群中致病原因的前几位依次是白内障(47.9%),眼底病(20.4%),屈光不正(9.52%),角膜病(7.59%).另外,脑垂体瘤致盲占0.74%.结论 广州市萝岗区≥50岁老年人群盲与低视力的首要原因为白内障,故降低自内障的患病率是该地区防旨治盲的关键,另外眼底病在该地区也是重点防治的疾病.     

海口市郊≥50岁人群的视力损伤及患盲病率调查

目的:调查海南省海口市郊≥50岁人群中视力损伤、严重视力损伤及盲的患病率,并分析其主要原因。方法:选取海口市郊≥50岁人群,随机抽取30个抽样单位的850例进行调查。对受检人员进行矫正视力、外眼、前房、晶状体、玻璃体及眼底检查,调查该人群视力损伤、严重视力损伤及盲的患病率并分析主要原因。结果:调查850例中受检人员为786例,受检率为92.47%,视力损伤、严重视力损伤及盲的患病率分别为2.67%,0.64%和2.54%。致视力损伤、严重视力损伤及盲主要眼病依次为白内障、眼后节疾病、角膜瘢痕及其他疾病。结论:海口市郊≥50岁人群视力损伤、严重视力损伤及盲的首要病因是白内障,眼后节疾病、角膜瘢痕等疾患所致盲也占一定比例。      

云南省高海拔农村多民族聚居区盲和低视力患病率调查

目的 探讨云南省高海拔农村多民族聚居区贡山县盲和低视力患病率及分布特点。方法 采用整群随机抽样的方法。2008年2至4月选取云南省贡山县全年龄组常住居民作为调查对象。调查地点为人选居民所在的村庄。调查程序包括问卷调查、预调查、视力检查、眼压、裂隙灯显微镜检查及眼底检查。盲定义为较好眼最佳矫正视力＜0.05,低视力定义为较好眼最佳矫正视力≥0.05且＜0.3。按年龄、性别、职业、教育程度、民族及居住地海拔高度分别计算盲和低视力的患病率,同时确定盲和低视力的原因。患病率的分层比较采用四格表卡方检验、Rx2卡方检验、趋势卡方检验。结果 3070名入选对象中2460名接受检查,受检率为80.1％。其中有159例视力损伤,总体患病率为6.46％,包括19例双眼盲患者,46例单眼盲患者,49例双眼低视力患者,45例单眼低视力患者。视力损伤在不同民族之间差异无统计学意义(x2 =0.75,P=0.388),而视力损伤在不同海拔居住地的居民之间差异有统计学意义(x2 =18.34,P=0.000)。年龄大（≥70岁）、文盲和从事体力劳动者视力损伤患病率高,分别为2.24％、4.19％、5.65％。42.1％(8/19)的双眼盲患者的致盲原因是白内障,角膜混浊占26.32％ (5/19)及眼底异常占21.1％ (4/19)。白内障也是双眼低视力的主要原因,占42.9％ (21/49)。结论 白内障是云南省贡山县的主要致盲原因,需要当地卫生机构采取措施来降低当地盲和低视力患病率,尤其是白内障盲。     

2009年上海市宝山区大场社区60岁及以上人群盲和低视力患病率调查

目的 探讨上海市宝山区大场社区60岁及以上人群的盲和低视力患病率、致盲原因及其相关因素。方法 横断面现况调查研究。由上海市眼病防治中心和上海市宝山区疾病预防控制中心于2009年10至12月期间对上海市宝山区大场社区60岁及以上并在当地居住10年以上的常住户籍人口进行随机整群抽样调查。对调查对象完成视力、眼压、验光、裂隙灯显微镜、免散瞳数字眼底照相等检查,采用世界卫生组织视力损伤标准和日常生活视力和视力损伤标准确立盲或低视力,并明确主要致盲原因。组间率的比较采用卡方检验。结果 实际受检4545人,受检率为87.42％。受检人群均为近10年内随着城市化进程从原农村人口转变而来的城市人口。按照世界卫生组织视力损伤标准：双眼盲30人,患病率0.67％;双眼低视力145人,患病率3.19％。白内障、黄斑变性、眼球萎缩或缺如、青光眼、糖尿病视网膜病变（或角膜病）是前5位致盲眼病。女性低视力患病率高于男性,差异有统计学意义(x2 =4.88,P＜0.05)。按照日常生活视力和视力损伤标准：双眼盲39人,患病率0.86％,双眼低视力401人,患病率8.82％;75岁后成为视力损害的高速发展期。白内障、未矫正的屈光不正、黄斑变性、眼球萎缩或缺如、青光眼是前5位致盲原因。女性低视力患病率高于男性,差异有统计学意义(x2=13.345,P＜0.01)。结论 在上海市城市化进程较快的老龄化社区中,白内障、未矫正的屈光不正、黄斑变性是引起日常生活视力盲的前3位原因,女性低视力患病率明显高于男性。对这类社区居民需要进行更多的有针对性眼的保健教育与服务工作。     

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.