Binocular adaptation to near addition lenses in emmetropic adults

Near addition lenses are prescribed to pre-presbyopic individuals for treatment of binocular motor problems such as convergence excess and to control the progression of myopia. To date, no investigation has looked at the complete sequence of binocular motor responses during a period of near work with +2D lenses. This investigation evaluated changes to accommodation and vergence responses when young adults sustained fixation at 33 cm with +2D addition lenses. In addition, the effect of the accommodative vergence cross-link (AV/A) on the magnitude and the completeness of binocular adaptation to these lenses were evaluated. The results showed that +2D lenses initiate an increase in exophoria and convergence driven accommodation. The degree of the initial induced phoria was dependant upon the magnitude of the AV/A ratio. Vergence adaptation occurred after 3 min of near fixation and reduced the exophoria and convergence driven accommodation. The magnitude of vergence adaptation was dependant upon the size of the induced phoria and hence the AV/A ratio. The completeness of adaptation was seen to vary inversely with induced exophoria and thus the AV/A ratio.     

三维重建模型模拟拉力螺钉固定髋臼后柱骨折的研究

目的　为经坐骨小切迹置入拉力螺钉内固定髋臼后柱骨折提供应用解剖学基础。 方法　用60例正常成人骨盆CT数据（男30例,女30例）,导入Mimics14.1行三维重建,观测骨盆三维模型髋臼后柱的纵轴走向,模拟置钉并确立螺钉穿出点。测量髋臼后柱纵轴的长度、后柱纵轴与冠状面夹角α和矢状面的夹角β,测量进针点及后柱盆腔侧、髋臼侧骨皮质厚度。 结果　髋臼后柱轴线向下穿出点位于坐骨小切迹中点,向上穿出点位于弓状线后端与髂前上棘连线中点。髋臼后柱纵轴的长度男性（105.04±　4.29）mm、女性（101.80±3.20）mm,α角男(33.41±2.18)°、女(31.56±2.71)°,β角男(21.74±1.19)°、女(19.15±　1.24)°。进钉点骨皮质厚度为(5.54±0.46)mm,盆腔侧和髋臼侧分别为(1.45±0.13)mm、(1.04±0.10)mm。 结论　三维重建模拟经坐骨小切迹中点行后柱拉力螺钉内固定,可快捷、准确测量钉道参数并进行术前评估,用该方法置入拉力螺钉固定后柱安全简便。     

角膜塑形镜对近视眼调节微波动幅度和调节滞后的影响

目的 研究近视眼配戴角膜塑形镜后调节微波动幅度和调节滞后的改变。方法 横断面研究。选取在视光门诊规范验配、随诊、配戴角膜塑形镜者15例作为观察组,框架眼镜者15例作为对照组;使用开放视野型红外验光仪（WAM-5500） 测量两组在0~4 D的调节刺激下的调节反应,计算相应的调节微波动幅度、调节滞后值和调节误差指数。对两组相关数据进行独立样本t检验。结果 在0、1、2、3、4 D调节刺激下,角膜塑形镜组的调节微波动幅度均大于框架眼镜组,且差异有统计学意义（t=3.704、3.277、2.365、2.179、2.591,P均<0.05）。角膜塑形镜组的调节滞后值均小于框架眼镜组,在2,3和4 D调节刺激下,两组差异有统计学意义（t=-2.208,-2.244,-2.098,P均＜0.05）;而在0和1 D调节刺激下,两组差异无统计学意义（t=-1.974、-1.758,P＞0.05）。角膜塑形镜组的调节误差指数小于框架眼镜组,且差异有统计学意义（t=-2.098,P<0.05）。结论 近视眼配戴角膜塑形镜后,调节微波动幅度增大;在高调节需求时,调节滞后值减小,这为其延缓近视的进展提供了一定依据。     

动态检影法下近视患者反应性与刺激性AC/A

目的通过测量调节滞后量和眼位,研究在不同调节刺激下,患者反应性AC/A和刺激性AC/A的相关性。方法横断面研究。选择在校大学生29例,在全矫基础上,利用棱镜分离法测量被检者[平均年龄（23.3±3.8）岁,除近视外,无其他眼部及全身疾病]在5 m和40 cm处的隐斜量。在全矫度数的基础上添加+1.00、+1.50、-1.00、-2.00 D球镜,重新检查被检者在40 cm处的隐斜视,应用MEM动态检影法测量患者的调节滞后量。采用秩和检验对数据进行统计分析。结果在不同的调节刺激下,患者的调节滞后量、梯度法反应性AC/A及梯度法刺激性AC/A的差异均有统计学意义（x²=116.85、8.992、17.319,P<0.05）。基于梯度法得到的反应性AC/A与刺激性AC/A均呈正相关（+1.00 D：r=0.542,P<0.01;-1.00 D：r=0.789,P<0.01;-2.00 D：r=0.812,P<0.01）。基于计算法得到的反应性AC/A与刺激性AC/A也呈正相关（r=0.859,P<0.01）。结论附加负球镜时,调节滞后量更大。计算法求的反应性AC/A与刺激性AC/A的相关性最好。     

高原地区老年抑郁症临床特点研究

目的：研究高原地区≥60岁老年抑郁症的临床特点。方法：选用青海大学附属医院、青海第三人民医院门诊和住院老年抑郁症患者150例,并引用尹秀茹、罗国军等南京脑科医院老年精神病住院病人124例进行比较分析。结果：两组老年抑郁症女性患者明显高于男性,病前大多数都有社会和心理因素。遗传因素对老年人影响相对较小,躯体不适、焦虑、疑病是老年抑郁症的共性。自杀观念、自杀行为低于平原组,差别有非常显著性（P〈0．001）,迟滞高于平原组,差别有非常显著性（P〈0．001）,激越低于平原组,差别有显著性（P〈0．05）。而睡眠障碍、记忆力下降在高原地区老年抑郁症中较为突出。结论：高原地区老年抑郁症与平原地区老年抑郁症不同,高原地区更易出现心境抑郁和迟滞,但激越、自杀观念和自杀行为却明显低于平原。     

青少年近视眼配戴RGPCL、Ortho—K及框架眼镜一年后调节滞后的差异

目的探讨青少年近视眼配戴硬性透气性角膜接触镜（rigid gas permeable contact lens,RGPCL）、角膜塑型镜（orthokeratology,Ortho—K,OK镜）及框架眼镜后调节滞后的差异。方法70名（70眼）9～14岁中低度青少年近视眼患儿,行医学验光、角膜曲率、角膜地形图检查后,根据检查结果、患儿及家长依从性等综合评估,对其中25名患儿选择配戴RGPCL,25名患儿配戴Ortho—K,其余20名患儿配戴框架眼镜。配戴期间每3个月复查1次,1年以后测定RGPCL组戴镜屈光度、Ortho—K组脱镜后的残余屈光度及框架眼镜组的屈光度．并使用开放视野型红外验光仪测量其在2～5D调节刺激下的调节反应．计算相对应的调节滞后和调节反应／刺激（AR／AS）斜率。对相关数据采用单因素方差分析的LSD检验。结果总共有57人完成测量。在2D调节刺激水平下,RGPCL、Ortho—K和框架眼镜组的调节滞后值间差异无统计学意义（P〉0．05）;在3D、4D、5D调节刺激水平下,3组问的调节滞后值差异均具有统计学意义（F=4．373,P〈0．05;F=5．833,P〈0．01;F=6．157,P〈0．01）,Ortho—K组的调节滞后值最小,RGPCL组次之,而框架眼镜组的调节滞后值最大。调节反应／刺激（AR／AS）斜率也呈现同样趋势,但3组间差异无统计学意义（P〉0．05）。结论配戴RGPCL和Ortho—K1年后,患儿在高调节需求时的调节滞后值明显低于框架眼镜组,其在延缓青少年近视进展中可以起到积极的作用。     

Accommodative spasm in siblings: A unique finding

Accommodative spasm is a rare condition occurring in children, adolescents, and young adults. A familial tendency for this binocular vision disorder has not been reported. I describe accommodative spasm occurring in a brother and sister. Both children presented on the same day with complaints of headaches and blurred vision. Treatment included cycloplegia drops and bifocals. Siblings of patients having accommodative spasm should receive a detailed eye exam with emphasis on recognition of accommodative spasm.     

热浪对居民循环系统疾病死亡影响的病例交叉研究

目的 探讨浙江省嘉兴市热浪对居民循环系统疾病日死亡人数的影响。 方法 本研究中热浪定义为日最高温度不低于35 ℃,且持续不少于3 d。采用时间分层的病例交叉设计方法,调整每日平均气温、降水量、平均风速、平均气压和空气污染指数建立条件Poisson回归模型,分析嘉兴市2008~2011年热浪与居民循环系统疾病死亡的关系,并分析滞后效应。 结果 2008~2011年共出现6次热浪。滞后2 d时热浪对循环系统疾病死亡数影响的效应值最大,RR值为1.342(95%CI:1.081~1.667)。热浪对≥65岁老年人在滞后2 d时RR值最大,为1. 296(95%CI: 1.027~1.636),对女性在滞后2 d时RR值最大,为1. 407(95%CI: 1.021~1.937)。 结论 热浪会增加循环系统疾病死亡风险,且存在滞后效应;≥65岁老年人和女性为脆弱人群。     

A model for accommodation in the young human eye: The effects of lens elastic anisotropy on the mechanism

An explanation of the mechanism of visual accommodation depends heavily on understanding the mechanical properties of the lens, as well as the way in which its shape is altered in small accommodative changes. An initial attempt to relate these properties to a mechanism has already been performed (Koretz and Handelman, 1982) for the young (age 11 yr) human lens, using certain simplifying assumptions (spherical curvature on the anterior lens surface and elastic isotropy). However, since it has been shown that the lens behaves as an anisotropic body, the previous treatment has been extended to include the variation of lens elastic properties in the polar and radial directions. With this modified representation, it is found that only one combination of elastic constants is consistent with the generally accepted qualitative theory of accommodation and with clinical data on the accommodative range of the emmetropic age 11 human eye. For this unique solution of the equations, however, the general mechanism already suggested by us, which includes support by the vitreous and alteration of the magnitude and angle of application of zonular force with accommodation, remains little changed.     

Behavioral measurements of accommodative amplitude in rhesus monkeys

The extent of voluntary accommodation was investigated behaviorally in two young rhesus monkeys and an adult human using a modified minus-lens technique. Specifically, contrast sensitivity for a high spatial frequency grating was determined as a function of spectacle lens power. Accommodative amplitudes derived from contrast sensitivity vs lens power functions indicate that young monkeys have at least 17 to 18 D of voluntary accommodation and that the accommodative amplitudes of monkeys are larger than those of equivalent-aged humans.