调节近点与近视眼的相关性研究

目的 探讨不同屈光状态下眼的调节近点（near poira of accomodation，AN）改变的意义，分析调节近点异常在近视眼发生、发展中的作用，进一步了解眼调节近点变化与近视眼的因果关系。方法 对248名（493只眼）近视青少年患者按照年龄和近视度数进行分组，并行屈光状态的检查，采用移近法获得调节近点距离。结果在9～10岁年龄组中，低度和中度近视组AN数值增加。在11～15岁和16～18岁年龄组中，低度近视组AN数值增大，高度近视组AN数值减少。结论 高AN数值可能是由于长期视近而造成调节力的滞后或不足引起的，这种滞后或不足可能是诱发近视不断加深的原因之一。可以认为AN远移可能是近视眼发生、发展的前兆。     

视觉训练对青少年假性近视正相对调节的影响

目的：探讨视觉训练对青少年假性近视正相对调节的改变。

方法：对42例84眼青少年假性近视患者随机分为视觉训练组和观察对照组,统计两组训练4wk后的视力、平均屈光度及两组训练前和训练后1,2,4wk后的5m时正相对调节量情况,并进行相关性分析。

结果：训练4wk后两组视力比较差异有统计学意义(P<0.05),两组平均屈光度比较差异无统计学意义(P>0.05); 训练1,2,4wk后的5m正相对调节量两组比较有统计学意义(P<0.05),视觉训练组训练前与训练4wk后的5m时正相对调节差异显著(P<0.01)。

结论：视觉训练对青少年假性近视患者正相对调节影响显著。     

青少年近视眼防治研究进展

近年来，青少年近视眼发病率不断上升，成为日趋严重的社会问题，并成为新的研究热点。关于近视眼形成机制，新的形觉剥夺学说的提出对于传统的调节学说以及现有的近视眼防治工作提出了强有力的挑战。本文将根据近年有关文献，对常用的近视矫正与防治措施对于青少年近视进展的影响进行综述如下。     

刺激小脑顶核对青少年近视眼调节影响的初步探讨

目的 评估刺激小脑顶核对青少年近视眼调节功能的影响。方法 收集我院门诊8名轻度近视儿童，用刺激小脑顶核的方法对受试者实施电刺激。检测刺激前后颈动脉及眼视盘血流参数，用综合验光仪检测刺激前后的单双眼相对性调节，调节幅度，调节灵敏度。结果 8名受试儿童刺激后1个月的调节功能各项指标均有显著性改善。结论 通过体外刺激小脑顶核可明显改善青少年近视的调节功能，但对于调节功能的改善与眼屈光发展的关系，以及是否能延缓近视形成，有待进一步研究。     

青少年近视眼的流行病学研究

近视是危害青少年视力的首要原因，直接影响青少年的身心健康和学习。近几年发病呈上升趋势，引起国内外眼科界的关注。近年来，不论是在流行病学研究、临床治疗研究，还是在发病机制的基础研究方面，近视眼已日益成为研究的焦点。本文就青少年近视眼的流行病学概况做一简要概述。     

青少年近视眼预测保健系统的临床应用研究

近视眼预测保健系统是通过对儿童眼轴、角膜曲率、前房深度的测量及相关资料,通过近视眼预测系统的计算,以了解儿童当前的客观屈光状态,从而提出保健意见.1 资料与方法1.1 对象选择1998年12月～2000年4月以来我院就诊的青少年、儿童200例400眼,其中男92例184眼,女108例216眼,年龄4～15岁.1.2 预测系统组成专用眼科A超、角膜曲率计、电脑验光仪、电脑一台、青少年近视眼预测保健系统软件.1.3 方法每名患者均进行视力检查、电脑验光、角膜曲率检查、A超测得眼轴、前房深度,晶状体厚度的数据及输入家族情况、用眼时间等相关因素,资料经青少年近视眼预测系统运算,指出儿童将来屈光状态,提出对患儿的保健意见.     

青少年近视发病机理的研究

随机选择除屈光不正外无其它眼病的健康学生８００例，通过长达８年系统动态观察及深入研究，以探索青少年近视的发病机理，结果表明，微量元素锌，铜及必需元素钠的含量减少，过度调节，遗传和眼轴的超长延长等因素对近视的形成有非常密切的关系。青少年近视的遗传方式以常染色体显性遗传为主。     

青少年近视眼的急斜和正透镜对隐斜的影响

目的 研究青少年近视眼的隐斜和正透镜对隐斜的影响。方法 用隐斜计测定１５１例不同屈光度青少年在裸眼,戴矫正镜片和矫正镜片再加＋１．５０Ｄ球镜条件下看近的隐斜度,结果近视各组倾向外隐斜,戴矫正镜片时外隐斜明显减少,再加正透镜后外隐斜又明显增加,结论 从调节和集合平衡的观点出发,青少年近视眼以戴矫正眼镜为好,正透镜的应用要采取慎重态度。     

角膜塑形镜对青少年近视患儿正相对调节力的影响

目的：观察配戴角膜塑形镜对于青少年近视患儿正相对调节力(PRA)改变的影响。

方法：回顾性病例分析。分析2016-09/2017-12间在我院视光科门诊初次就诊的青少年近视性屈光不正患儿122例244眼。其中选择角膜塑形镜矫正者63例(塑形镜组),选择框架眼镜矫正者59例(框架眼镜组),比较两组患儿治疗前及治疗6mo时双眼PRA的改变情况。

结果：治疗前塑形镜组PRA值-0.83±0.23D,框架眼镜组-0.77±0.24D(t=-1.457,P>0.05)。治疗前塑形镜组眼轴24.84±0.90mm,框架眼镜组24.78±0.86mm(t=0.550,P>0.05)。治疗6mo时塑形镜组PRA值-2.27±0.37D,与治疗前有差异(t=37.070,P<0.001)。治疗6mo时框架眼镜组PRA值-0.83±0.24D,与治疗前无差异(t=1.565,P>0.05)。治疗后塑形镜组PRA优于框架组(t=-25.271,P<0.001)。治疗6mo时塑形镜组眼轴24.86±0.91mm,与治疗前24.84±0.90mm有差异(t=-2.453,P<0.05)。治疗6mo时框架眼镜组眼轴24.97±0.86mm,与治疗前24.78±0.86mm有差异(t=39.135,P<0.001)。治疗6mo时两组眼轴无差异(t=-0.932,P>0.05)。

结论：青少年近视患儿配戴塑形镜相比配戴框架眼镜在治疗6mo时可明显提高其双眼PRA储备,但两者眼轴改变差异不明显。     

LASIK对近视患者调节和隐斜的影响

目的　探讨LASIK手术对近视患者调节和隐斜的影响。方法　对LASIK手术的近视患者 60人在术前和术后一个月进行调节力和看近隐斜度的测定 ,并进行对比分析。结果　术前调节力平均值为 6 77D± 1 41D ,术后调节力平均值为 7 3 9D± 1 2 5D。统计学分析二者之间的差异有非常显著性意义 (t =6 887,P <0 0 1)。术前裸眼隐斜度的平均值为 -10 18± 5 0 7Δ。术前戴矫正镜片隐斜度的平均值为 -1 99± 6 49Δ ;术后裸眼隐斜度的平均值为 -4 92± 4 46Δ。统计学分析 ,术前裸眼与戴矫正镜片隐斜度平均值之间的差异有非常显著性意义 (t =11 898,P <0 0 1) ;术前裸眼与术后裸眼隐斜度平均值之间的差异有非常显著性意义 (t =11 10 1,P <0 0 1) ;术后裸眼与术前戴矫正镜片隐斜度平均值之间的差异有非常显著性意义 (t =3 0 45 ,P <0 0 1)。结论　LASIK手术后近视患者的调节力有一定增加。矫正眼镜和LASIK手术可以减少近视患者看近外隐斜。较长期的影响尚有待于观察。     

成年近视患者主视眼与调节因素间关系的研究

背景 主视眼是人类具有功能不对称行为的器官之一,它和非主视眼在很多方面的差异一直是基础研究和临床研究的热点,但基于成年近视患者调节功能方面的研究相对较少. 目的 研究成年近视患者主视眼和非主视眼与调节相关各因素之间的关系.方法 采用描述性系列病例观察的研究方法,纳入35例年龄为18～ 35岁、双眼屈光不正球镜度为-2.00 ～-10.00 DS、散光度≤1.50 DC且双眼屈光参差≤1.5 DS、最佳矫正视力(BCVA)≥1.0的单纯近视患者,采用卡洞法并结合拇指法判断主视眼的眼别,采用主观、客观综合验光法获得受检眼屈光不正的度数,用移近法测量单眼的调节幅度,以附加±0.50 D融合交叉柱镜(FCC)法测量受检眼的调节滞后情况,采用翻转法测量各眼的调节灵敏度. 结果 本组患者的主视眼与非主视眼调节幅度分别为(9.69 ±2.30)D和(9.60±2.37)D,调节灵敏度分别为(11.08±4.20) cpm和(10.63±4.60) cpm,调节滞后量分别为0和0.25 D,主视眼与非主视眼间的差异均无统计学意义(P=0.294、0.260、0.141).右眼为主视眼的患者双眼调节幅度分别为(9.48±2.29)D和(9.33±2.49)D,调节灵敏度分别为(10.50±4.70)cpm和(9.99±4.90) cpm,差异均无统计学意义(P=0.319、0.116),双眼调节滞后量的差异无统计学意义(P=0.590).左眼为主视眼的患者双眼调节幅度分别为(9.91±2.35)D和(9.88±2.26)D,调节灵敏度分别为(10.70±3.77) cpm和(11.25±4.27) cpm,差异均无统计学意义(P=0.749、0.295),双眼调节滞后量间的差异无统计学意义(P=0.238).结论 对于无或有较小屈光参差的成年近视患者,主视眼和非主视眼在调节幅度、调节灵敏度及调节准确性方面无差别.     

Effect of positive and negative defocus on contrast sensitivity in myopes and non-myopes

This study investigated the effect of lens induced defocus on the contrast sensitivity function in myopes and non-myopes. Contrast sensitivity for up to 20 spatial frequencies ranging from 1 to 20 c/deg was measured with vertical sine wave gratings under cycloplegia at different levels of positive and negative defocus in myopes and non-myopes. In non-myopes the reduction in contrast sensitivity increased in a systematic fashion as the amount of defocus increased. This reduction was similar for positive and negative lenses of the same power (p = 0.474). Myopes showed a contrast sensitivity loss that was significantly greater with positive defocus compared to negative defocus (p = 0.001). The magnitude of the contrast sensitivity loss was also dependent on the spatial frequency tested for both positive and negative defocus. There was significantly greater contrast sensitivity loss in non-myopes than in myopes at low-medium spatial frequencies (1-8 c/deg) with negative defocus. Latent accommodation was ruled out as a contributor to this difference in myopes and non-myopes. In another experiment, ocular aberrations were measured under cycloplegia using a Shack-Hartmann aberrometer. Modulation transfer functions were calculated using the second order term for defocus as well as the fourth order Zernike term for spherical aberration. The theoretical maximal contrast sensitivity based on aberration data predicted the measured asymmetry in contrast sensitivity to positive and negative defocus that was observed in myopic subjects. The observed asymmetry in contrast sensitivity with positive and negative defocus in myopes may be linked to the altered accommodative response observed in this group.     

Characteristics of accommodative behavior during sustained reading in emmetropes and myopes

Accommodation has long been suspected to be involved in the development of myopia because near work, particularly reading, is known to be a risk factor. In this study, we measured several dynamic characteristics of accommodative behavior during extended periods of reading under close-to-natural conditions in 20 young emmetropic and stable myopic subjects. Accommodative responses, errors, and variability (including power spectrum analysis) were analyzed and related to accommodative demand and subject refractive error. All accommodative behaviors showed large inter-subject variability at all of the reading demands. Accommodative lags and variability significantly increased with closer demands for all subjects (ANOVA, p<0.05). Myopes had significantly greater variability in their accommodation responses compared to emmetropes (ANOVA, p<0.05) and had larger accommodative lags at further reading distances (unpaired t test p<0.05). Power spectrum analysis showed a significant increase in the power of accommodative microfluctuations with closer demands (ANOVA, p<0.05) and with increasing myopia at the closest reading demand (ANOVA, p<0.01). The difference in the stability of the accommodative behavior between individuals with different refractive states suggests a possible relationship between variability in accommodation and the development of myopia.     

调节状态下眼内接触镜在眼内位移的临床观察

目的 研究调节状态下的后房型有晶状体眼人工晶状体(P-IOL)眼内接触镜(ICL)在眼内的相对位移情况.方法 系列病例研究.连续收集2008年4月至2008年10月在首都医科大学附属北京同仁医院进行ICL植入矫正高度近视的患者41例(41只眼).检查手术前后的视力、调节力,以及术后非调节状态和毛果芸香碱药物诱导调节下的ICL和自身晶状体的位移及相对位置.对等效球镜度数、散光度数、调节力、人工晶状体移动度等数据采用t检验进行统计学分析.结果 术后3个月患者裸眼矫止远、近视力均达到或高于术前最佳矫正视力.术前平均调节力(2.12±1.06)D,术后3个月平均调节力(4.46±2.11)D,较术前明显提高(t=2.312,P=0.022).ICL后表面至自身晶状体前囊的距离在非调节状态下为(0.48±0.27)mm,在药物诱导调节状态下为(0.34±0.19)mm,两者差异有统计学意义(t=2.104,P=0.038).角膜内皮至ICL前表面的距离在两种状态下差异无统计学意义(t=1.165,P=0.149).角膜内皮至自身晶状体前囊的距离在两种状态下差异虽无统计学意义(t=1.821,P=0.071),但可以见到自身晶状体的前极发生了比较明显的前移位的现象.超声活体显微镜(UBM)检查可见,部分手术眼在调节和非调节状态下ICI 的襻部与晶状体赤道部均存在接触.结论 虽然在药物诱导调节的过程中,伴随的缩瞳现象使得ICL与自身晶状体之问的距离明显缩小,但在中央区两者之间的距离对于避免前囊下白内障的形成仍然是足够的.两者在周边部的接触可能是引起晶状体周边囊膜下混浊的原因之一,但其对于中央部囊膜下混浊发生的影响还需要进一步研究.     

Clinical and laboratory investigations of the relationship of accommodation and convergence function with refractive error

Studies of the relationship of clinical and laboratory measures of accommodation and convergence function with refractive error are reviewed. There are inconsistencies in results from study to study presumably due, in part, to methodological differences. However, some basic trends can be outlined. In studies in young adults, accommodation in darkness (dark focus), optical reflex accommodation, and proximally induced accommodation are less in myopes than in emmetropes and hyperopes. It also appears that nearpoint esophoria is associated with higher rates of myopia progression in children. Implications for myopia etiology are discussed.     

儿童和青少年近视调节功能的临床分析

目的 探讨发病早期的儿童和青少年近视的调节功能状态,分析主导眼和非主导眼的调节功能水平.方法 应用动态检影法和移近法分别测量50例发病1～2年的学龄期儿童和青少年近视患儿调节滞后和调节幅度;同样方法测量20例正视儿童和25例远视屈光不正患儿;检测其主导眼和非主导眼.结果 近视患儿的主导眼和非主导眼的调节幅度和调节滞后与正视儿童均差异无统计学意义;而其主导眼和非主导眼的调节幅度比远视患儿明显更大(t=2.21,P=0.03＜0.05;t=2.83,P=0.006＜0.05);两组的调节滞后差异无统计学意义.50例近视患儿主导眼和非主导眼的调节滞后值分别为(0.73±0.31)D和(0.81±0.38)D,主导眼和非主导眼间差异有统计学意义(t=2.14,P=0.038＜0.05);调节幅度分别为(13.39±3.51)D和(13.26±3.60)D,差异无统计学意义.95例观察对象(近视、正视和远视患儿)的主导眼的调节滞后度为(0.68±0.36)D,非主导眼调节滞后度为(0.75±0.34)D,主导眼和非主导眼间的差异有统计学意义(t=2.06,P=0.042＜0.05);主导眼调节幅度(12.9±3.09)D,非主导眼为(12.6±3.09)D,差异无统计学意义(t=1.49,P=0.14).结论 发病早期的儿童和青少年近视的调节滞后值和调节幅度与正视儿童无明显差别;调节幅度比远视儿童的更大.儿童和青少年主导眼的调节滞后比非主导眼的更小,进行调节滞后相关研究时应注意主导眼和非主导眼的区别.     

青少年眼调节与非调节状态下眼前节结构生物测量对比分析

目的 探讨小学生和中学生在调节和非调节状态下眼前节部分解剖结构的动态变化规律。方法 横断面研究。采用超生生物显微镜（UBM）检测福州市54例小学生及55例中学生在调节和非调节状态下的睫状体、虹膜及房角等位置相关数据,数据采用配对t检验和独立样本t检验进行分析。结果 非调节状态下小学生组各指标数值如下：睫状突长度（CPD）值（160.53±17.78）μm,睫状突宽度（CT）值（90.01±34.30）μm,虹膜睫状体距离（ICPD）值（23.11±3.33）μm,虹膜厚度（IT）1值（35.95±6.60）μm,IT2值（52.81±9.94）μm,小梁睫状体距离（TCPD）值（151.27±23.11）μm,巩膜外侧面与虹膜长轴的夹角θ3值（39.23±7.46）°,虹膜外侧面与睫状突的夹角θ4值（56.02±6.75）°;调节状态下相应指标分别为：（187.62±15.44）μm、（74.23±19.87）μm、（19.78±2.69）μm、（30.34±5.83）μm、（47.11±6.71）μm、（131.55±20.02）μm、（31.68±5.14）°、（50.39±4.89）°。调节与非调节状态下比较,差异均有统计学意义（t=8.45、2.93、5.72、4.68、3.49、4.74、6.12、4.96,P＜0.05）。中学生组非调节状态下以上各指标分别为：（214.64±15.25）μm、（99.13±17.80）μm、（27.92±9.00）μm、（40.72±6.43）μm、（56.57±9.13）μm、（176.82±28.06）μm、（43.73±6.93）°、（60.15±10.48）°;调节状态下分别为：（271.38±11.96）μm、（93.27±10.42）μm、（21.66±7.54）μm、（35.68±4.37）μm、（50.17±6.49）μm、（136.41±19.35）μm、（39.51±5.28）°、（53.68±9.12）°。调节与非调节状态下各参数比较,差异均有统计学意义（t=20.91、2.03、3.81、4.63、4.08、8.47、3.46、3.33,P＜0.05）。同样在调节状态下,小学生组和中学生组所有睫状体相关指标之间差异都存在统计学意义（t=30.95、6.10、4.47、5.29、2.37、7.70、2.32、6.98,P＜0.05）。结论 人眼进行视近调节时,睫状体的变化最为显著,出现各部肌纤维尤其是环形肌协调收缩,并向前向内移动,使晶状体悬韧带松弛,实现眼屈光力的增加;且年龄越小,调节力越强。     

The association of wavefront aberration and accommodative lag in myopes

Accommodative lags, induced by a target at 33 cm (distance-induced condition) and by a -3.0 D lens (lens-induced condition), and wavefront aberrations were measured in 27 young myopic eyes. The accommodative lags and Strehl ratios derived from the wavefront aberrations in myopes were compared with those from 57 emmetropes. Accommodation was measured using a Canon R-1 autorefractor, while aberrations were measured using a psychophysical ray-tracing technique. In accord with previous results, larger accommodative lags were found for the myopes than the emmetropes in both the lens-induced and distance-induced conditions. The mean Strehl ratio was smaller in the myopes (0.079) than the emmetropes (0.091); this difference approached significance (p = 0.055). In addition, for myopes the accommodative lag was significantly correlated with the Strehl ratio in the lens-induced condition (r = -0.45, p < 0.02) and approached significance in the distance-induced condition (r = -0.35, p = 0.07). No significant correlations were found for emmetropes. Possible reasons to account for these results are discussed.     

Changes in dynamics of accommodation after accommodative facility training in myopes and emmetropes

This study evaluates the effect of accommodative facility training in myopes and emmetropes. Monocular accommodative facility was measured in nine myopes and nine emmetropes for distance and near. Subjective facility was recorded with automated flippers and objective measurements were simultaneously taken with a PowerRefractor. Accommodative facility training (a sequence of 5 min monocular right eye, 5 min monocular left eye, 5 min binocular) was given on three consecutive days and facility was re-assessed on the fifth day. The results showed that training improved the facility rate in both groups. The improvement in facility rates were linked to the time constants and peak velocity of accommodation. Some changes in amplitude seen in emmetropes indicate an improvement in facility rate at the expense of an accurate accommodation response.