Vimentin在正常家兔舆白内障家兔眼晶體的分布

目的探討Vimentin細胞骨架蛋白在正常家兔眼晶體中不同區域的分布舆白内障家兔晶體中Vimentin含量的對比,從而論證Vimentin在致障中的代謝活曜.方法選取成年健康家兔13衹及白内障家兔13衹取左眼晶體,采用免疫熒光染色法,照相,計算機圖像分析(灰度值X±S).結果發現Vimentin陽性物在晶體赤道部表面水平最高,在向晶體中部移行的過程中陽性程度逐漸下降,最後消失,同時表明健康家兔舆白内障家兔晶體中Vimentin的含量有顯著差异(P＜0.05).結論提示在致障方面Vimentin有明顯改燮.     

关于眼屈光调节机制的探讨——晶体移位说和二元调节论

人眼能看清远近不同距离的物体,是需要进行屈光调节的。我们发现,调节的方式不是通过晶体变形来实现,而是通过晶体移位来实现:看速时晶体向前移位,看近时晶体向后移位——晶体移位说。但这不是屈光调节机制的全部内容,屈光调节机制还包括:视速共轭调节(视角调节)和视近共轭调节(焦距调节)的作用——二元调节论。晶体移位说和二元调节论,构成了眼屈光调节机制的全部内容。用这个调节理论,可以重新认识屈光状态的定义,修正晶体变形说的偏见,并且对青少年近视的成因与老视现象等做了全新的解释。     

Accommodation, refractive error and eye growth in chickens

We raised chickens with defocusing lenses of differing powers in front of their eyes. For this purpose, small hoods made from soft, thin leather were carefully fitted to their heads. Lenses were attached to the hoods by velcro fasteners and could be easily removed for cleaning. The powers of the lenses were such that their optical effects could be compensated for by accommodation. It was verified by infrared (IR) photoretinoscopy that the chickens could keep their retinal images in focus. Wearing a lens resulted in a consistent shift of the non cycloplegic refractive state (measured without the lens) which was in the direction to compensate for the lens. We used a sensitive technique (precision = +/- 50 micron as estimated from the variability of repeated measurements) to measure the posterior nodal distance (PND) in excised eyes of birds grown with lenses. The PND, in turn, was used to compare eyes treated with different lenses. It was found that the PND was increased in eyes which were treated with negative lenses compared to those treated with positive lenses. This effect occurs independently in both eyes and it is not due to changes in corneal curvature. We discuss our result in terms of a closed-loop feedback system for the regulation of eye growth.     

人眼屈光状态的泛化理论及有效眼模式

目的：人眼的屈光状态可由一新理论来分析，此理论基于几种不同眼生长部位的比值与实验值比较的结果。方法：由光学成像理论可知，眼系统屈光状态可由眼轴长(L)，主平面(L2)及角膜及晶状体有效焦距(f1，f2)、曲率(r1，r2，R1，R2)及两者有效距离(S)来表示。比值Cl=X／f1，X／f2，L／r1，L／R1的理论值符合实验值。本研究同时介绍一种有效眼模式(EEM)，其由X，C1及C2来描述。结果：在正视态时，(Cl，C2)=(0．59，0．29)，(L／r1，L／R1)=(3．08，2．3)，(E1，E2)=(0．7l，0．29)。在标准范围内，各值为(单位：mm)，n=(29—34)，f2=(60-64)，S=(5．0-6．5)。本理论求得L*=(22—25)，而比值C1=(0．56—0．6)，C2=(0．27—0．31)；L／r1=(2．8—3．3)，L／R1=(2．1—2．5)；E1=S／(f1-S)=(0．65—0．75)，E2=S/f2=(0．27—0．32)。本研究理论值L／r1符合Hong等人所测的实验值(2．75—3．28)。结论：人眼的发展可由本研究理论统一描述，EEM含C1，C2，E1，E2四个比值，可用来预测人眼最有可能的生长趋势(正视及非正视态).     

眼调节各因素与眼屈光不正的相关性

目的 :评价与眼屈光不正状态可能相关的各项眼调节功能状况 ,探讨眼屈光不正与眼调节之间的相关性。方法 :分别对 4 7名学生 94只眼进行屈光不正、调节幅度、调节灵敏度、调节准确度 (双眼交叉柱镜FCC法 )检查。然后将各项结果与屈光不正状况进行相关性统计分析。结果 :被检者的屈光不正度平均值为 (- 2 .4 6± 2 .2 8)D ,调节幅度均值为(7.90± 2 .95 )D ,调节灵敏度为 (17.2 8± 4 .92 )次 /min ,调节准确度均值为 (0 .5 8± 0 .6 0 )D ,其中调节幅度与眼屈光度有显著相关性 (r=0 .377,P≤ 0 .0 5 ) ;调节准确度与眼屈光度有显著相关性 (r=- 0 .4 71,P≤ 0 .0 5 )。结论 :眼的屈光不正与眼调节幅度和眼调节滞后量有显著相关 ;眼的调节灵敏度与屈光不正无明显关系。提示我们可通过训练调节幅度和准确度来减缓近视加深。     

The relationship between tonic accommodation and refractive error

It is now well established that accommodation adopts an intermediate resting position in the absence of visual stimulation. It also has been shown that this tonic position of accommodation exhibits considerable variation among individuals (ie, 0-4 D). Previous studies have been somewhat inconclusive as to whether these individual differences in tonic accommodation are related to the refractive properties of the eye. This study investigates the relationship between tonic accommodation and refractive error with particular reference to both the value and the time course of tonic accommodation. Sixty-two subjects were used for the study, with an age range of 19-25 yr. Subjects were placed into one of four refractive groups, after considering factors pertaining to the theories of refractive development. Darkroom measures of tonic accommodation were determined using the infrared objective autorefractor, Canon Autoref R-1. Significant differences were found among the four refractive groups, with corrected hyperopes having the highest dioptric value of tonic accommodation and corrected late-onset myopes having the lowest dioptric value. The significant difference found between early- and late-onset myopes is suggested as a possible reason for the inconclusive results of some previous studies. It also was found that the time taken to reach a stable tonic position of accommodation was much slower for the hyperopic group than for the other refractive groups. The results are discussed in the light of recent findings on accommodative hysteresis and with respect to a dual innervation to the ciliary muscle.     

两种矫正方式对近视患者AC/A的对比研究

目的:研究青少年近视患者在配戴角膜塑形镜与配戴框架眼镜后各自AC/A的变化情况,并进行对比分析,进一步明确角膜塑形镜与框架眼镜对近视患者视功能的影响,及对青少年近视的控制作用。方法:随机选取60例来我院成功验配角膜塑形镜的青少年近视患者作为试验组,随机选取60例门诊就诊并给予框架眼镜的青少年近视患者作为对照组,观察两组患者屈光矫正前后AC/A及等效球镜度的变化并进行对比研究。随访时间依次为戴镜1,3,6mo;1a。结果:试验组戴镜前和后1,3,6mo;1a的AC/A值分别为4.05±2.03,3.05±1.85,3.31±1.02,3.14±1.64,3.20±1.55,戴镜后1,3,6mo;1a与戴镜前比较,差异均有统计学意义(P<0.05)。对照组戴镜前和后1,3,6mo;1a分别为4.12±1.86,4.09±1.38,3.58±1.45,3.84±1.41,4.23±2.01,戴镜后1,6mo;1a与戴镜前比较,差异无统计学意义(P>0.05),戴镜后3mo与戴镜前比较,有显著差异(P<0.05)。两组戴镜前无显著差异(P>0.05);戴镜后1,6mo;1a,两组有显著差异(P<0.05);戴镜后3mo两组差异无统计学意义(P>0.05)。近视度数增长的观察时间为1a。试验组等效球镜度增加了0.38±0.35DS,对照组增加了0.84±0.56DS,两组差异有统计学意义(P<0.05)。结论:两种矫正方式都能降低高AC/A值,试验组较对照组能更快更好地改善调节与集合的关系,近视度数增长后AC/A值会偏高。角膜塑形镜对中低度近视的矫正有效,它较框架眼镜能更有效地控制青少年近视的增长速度,是目前控制近视的一种有效方法。它对近视患者视功能的改善机制还有待进一步的研究。     

Amplitude of accommodation and refractive error

This paper investigates the amplitude of accommodation of early onset myopes, late onset myopes, emmetropes, and hyperopes. Eighty subjects were used, 41 women and 39 men, with an age range of 18-22 yr (mean = 19.82). All subjects wore an optimum refractive correction, giving visual acuities of 20/20 or better. Significant differences were found between the four refractive groups, with late onset myopes having the largest amplitude of accommodation, followed by early onset myopes, emmetropes, and hyperopes. The results are discussed in the light of previous findings on tonic accommodation and the accommodative response gradient and interpretated in the context of a dual innervation to the ciliary muscle.