随机点立体视图点大小和密度对弱视儿童立体视的影响

目的 比较不同间距视力表对经治疗后的弱视儿童视力的影响,应用计算机立体视检查系统研究随机点大小和密度对经治疗后的弱视儿童立体视的影响.方法 本研究分两部分,研究对象为13例弱视儿童患者.用单个视标、1/4倍、1/2倍、1倍、2倍间距拥挤视力表分别检查13例弱视儿童的视力,比较使用5种视标间距视力表所得检查差异.应用计算机立体视检查系统对13例儿童进行立体视检查,分别按3种不同密度和4种不同随机点大小的检查并比较其差异.结果 不同间距视力表检查弱视儿童平均视力分别为(0.577±0.039)、(0.412±0.033)、(0.469±0.033)、(0.515±0.039)、(0.554 +0.045),成对比较显示不同组别间差异存在统计学意义.当随机点的大小固定时,密度不同随机点对儿童立体视锐度影响差异无统计学意义；当随机点密度相同时,大小不同随机点对儿童立体视锐度影响差异亦无统计学意义.结论 弱视儿童有拥挤现象,拥挤现象没有影响其随机点立体视锐度的检查,提示随机点立体视图视差信息的机制和视觉对精细视标的分辨机制不同.(中国眼耳鼻喉科杂志,2011,11:224-227)

Influence of different size and density of random-dot of the random-dot stereogram in stereopsis in amblyopic children

Objective To evaluate the vision crowding phenomenon and to use random-dot stereogram to study the influence of different size and density of random-dot in stereopsis in curative amblyopic children. Methods A twopart study was conducted in a referral practice. The subjects were 13 curative amblyopic children. Visual acuity （ VA ） charts with single target, and various times spacing examination were taken respectively to each of the 13 curative amblyopic children. The difference of VA was analyzed among the five groups. Random - dot stereogTam with four different size and three different density of random-dot was used to examine the stereopsis respectively in each of the 13 curative amblyopie children. The difference of stereopsis among the different size and density of random-dot groups was analyzed. Results The average VA of the single target , 0.25, 0.5,1 and 2 times spacing was （ 0. 577 ± 0. 039 ）, （ 0. 412 ± 0.033）, （0.469 ± 0.033 ）, （ 0. 515 ±0. 039 ） and （ 0. 554 ± 0. 045 ） respectively. Pairing comparison showed that there were significant difference among the five groups. There were no significant difference among the different kinds of density of random-dot when the size was constant. There were no significant difference among the different kinds of size of random-dot when the density was constant. Conclusions The vision crowding phenomenon still existed in curative amblyopie children. But the vision crowding phenomenon did not affect the random-dot in stereopsis. It suggested that the mechanisms of forming disparity graph of stereogram and the visual acuity be different.