【作者】 许贺；

【导师】 亢晓丽；

【作者基本信息】 中国医科大学 ， 眼科学， 2003， 硕士

【摘要】 前言 弱视是在小儿视觉发育敏感期内发生的常见眼病，它是由视觉剥夺和／或双眼相互作用异常所引起的单眼或双眼视力减退，没有可察觉的器质性病变。屈光参差是指双眼屈光状态或屈光度的不同，它是引起儿童弱视的一个常见的原因。弱视不仅表现为单眼或双眼视力的低下，更重要的是弱视形成后会影响到双眼视觉的形成和发展。立体视觉是双眼视功能的最高级形式，是视觉器官对物体三维空间结构的感知能力，它是人类和高等动物在三维空间中后天获得的一种视功能。随着科学技术的发展，良好的立体视觉作为从事许多职业，特别是各类精细工作的必要条件而越来越受到人们的重视。本文主要以儿童的屈光参差性弱视为研究对象，针对各种不同类型的屈光参差对视力和立体视的影响以及屈光参差、弱视、立体视三者之间的关系进行系统的研究。 目的 探讨多大程度的屈光参差会显著的影响视力和立体视功能以及屈光参差、弱视、立体视三者之间的相互关系。 方法 (1)研究对象的选取：选取不伴有斜视的屈光参差病人186例，无屈光参差和弱视的正常儿童20例，排除：有眼病史，既往经过正规的矫正或治疗及年龄太小无法配合检查者。 阻）分组：依据双眼屈光参差的性质将研究对象分为五组：远视性屈光参差（HA）组、近视性屈光参差（MA）组、散光性屈光参差（AA）组、综合病例组和对照组。 橱）检查与记录：检查双眼裸眼视力、眼位、眼底；双眼睫状肌麻痹条件下检影验光确定屈光状态；测最佳的矫正视力及矫正Tibous立体视；4D三棱镜试验排除微小斜视。视力用两种方法记录：第一种以小数记录，第二种将小数视力换算成对数视力（最小可分辨视角的对数值ogvxn太弱视的程度用弱视眼的b咖AR视力计量。综合病例组屈光参差的程度以双眼等效球镜的差值来计量；远视性、近视性和散光性屈光参差三组，屈光参差的程度以双眼屈光度的差值来计量，球镜或柱镜差值＜O．SD的忽略不计。 N）统计学处理：两组均数的比较用 student t检验，相关性分析采用 Spe－an rnk相关分析方法。 结 果 门）综合病例组：双眼屈光度差值＞1．OD，弱视的发生率明显提高为35％，有29％患者的立体视低于正常。屈光参差＞3D，100％形成弱视且立体视低于正常，其中31％为立体视盲。 p）对于不同类型的屈光参差：HA＞＊ OD，MA＞2．OD，AA＞l．OD弱视的发生率显著提高，分别为 43％A3％36％，平均立体视也显著下降，分别有43％上9％J6％的患者立体视低于正常；各种类型的屈光参差＞3D，100％形成弱视且立体视低于正常。 橱）屈光参差与弱视的相关性（R；）明显大于屈光参差与立体视的相关性（民人立体视与弱视的相关性（民）明显大于立体视与屈光参差的相关性（R＊。 ·2· 讨 论 屈光参差是形成弱视的一个重要原因，lff床上从是否有双眼单视（障碍）出发，把屈光参差分为生理性和病理性的，在临床工作中我们观察到不同性质的屈光参差对于视功能的影响也不完全一致。因此我们依据双眼屈光性质的不同对屈光参差进行了分类研究，结果表明：＊A＞1．OD、＊A＞2．OD人A＞1．OD弱视的发生率显著提高，立体视功能也明显下降，我们的结论与David的研究结果接近。而弱视的程度是否与屈光参差的程度相关，我们的研究表明：从总体上看屈光参差与弱视之间呈正相关，但不同性质的屈光参差二者的相关性不同，远视性屈光参差的相关性（R＝＝0．719）最强。对于不同性质的屈光参差对视功能影响略有不同的原因，我们分析它们在弱视的形成机制上可能存在差异。 所有类型的屈光参差，随着屈光参差程度的增加，立体视功能下降，立体视下降的程度与屈光参差的程度相平行，大于 3D的屈光参差，100％患者的立体视锐度低于正常，部分患者为立体视盲。我们认为由于儿童的屈光参差大多同时伴有弱视，屈光参差和弱视两种因素共同导致了立体视功能的下降，弱视在其中可能起主要的作用。 屈光参差，弱视，立体视三者密切相关，屈光参差是导致弱视和立体视下降的原因。我们对屈光参差、弱视和立体视三者进行相关性分析的结果表明：对于儿童的屈光参差性弱视，屈光参差可导致弱视和立体视功能的下降，但屈光参差与弱视的关系更为密切；而弱视和屈光参差均是导致立体视下降的原因，但在引起立体视下降的这两种因素中弱视的程度较屈光参差的程度更重要。因此我们应重视儿童的屈光参差，对于小儿的屈光参差性弱视应早期发现，尽早戴镜矫正同时进行弱视治疗，才能使患儿获得正常或 ·3·接近正常的双眼视功能。 结 论 O）儿童屈光参差患者当双眼屈光参差n 时，弱视发生率显著提高，平均立体视显著下降；当屈光参差＞3D时，视功能受到严重损害，近100％的患者形成弱视且立体视低于正常，?更多还原

【Abstract】 PurposeTo investigate the effects of various types of anisometropia on visual acuity and stereopsis. To study the relationship between anisometropia, amblyopia and steropsis.MethodsTo select the anisometropic patients without strabismus 186 cases , which had no history of treatment for refractive error or amblyopi-a, no other ocular diseases. The children too young to obtain reliable visual acuity and sensory data were excluded. To select 20 normal children without anisometropia and visual acuity > 0. 8 as control group. The anisometropic patients were divided into four groups; hy-permetropic anisometropia group ( HA ) , myopic anisometropia group ( MA) , astigmatic anisometropia group ( AA) and all anisometropic patients group. Recorded the uncorrected visual acuity and cycloplegic refraction in each eye. The best corrected visual acuity and stereopsis were recorded after the pupils resumed. The test of 4 - D triptich used to exclude the microstrabismus. The visual acuity and stereopsis data were used for statistic analysis.ResultWhen HA > ID,MA >2D,AA > ID the incidence of amblyopia are 43% , 43% , 36% and the level of stereopsis significantly decreased in each group, when all types anisometropia > 3 D, the incidence of amblyopia increased to 100% and the Titmus stereopsis of all the patients were subnormal in each group. The correlation between the degree of anisometropia and the severity of amblyopia are larger than the correlation between the degree of anisometropia and the stereopsis. The correlation between the stereopsis and the severity of amblyopia are larger than the correlation between the stereopsis and degree of anisometropia.DisccusionAnisometropia is a main causes of amblyopia, it is unclear what degree of anisometropia will affect visual acuity and stereopsis, and the effects of various types of anisometropia on visual acuity and stereopsis were not equal, so we divided the anisometropic patients into four groups, our investigation result were : When HA > ID, MA >2D , AA > 1D The incidence of amblyopia are significantly increased, which was equal to the David results. For all the patients, the severity of amblyopia was related to the degree of anisometropia, but the correlation were different for various types anisometropia. For the reason, maybe the mechanics of amblyopia were slightly difference to various types anisometropia.When the degree of anisometropia increase, the level of stereop-sis decreased. When anisometropia >3D, the stereopsis was nearly to absent. The correlation between the degree of anisometropia and the level of stereopsis are relatively small. Our results were little different to Halit Oguz’results through experimentally induced anisometropia. Most anisometropia companied with amblyopia in children, the naturally occurring anisometropia. was more complex than experimentally induced anisometropia. Anisometropia, amblyopia and stereopsis correlated tightly each others, anisometropia was the causes of amblyopia and subnormal stereopsis. But the correlation between anisometropia and amblyopia was strong relatively. However the stereopsis was tightly correlated with the severity of amblyopia.Conclusion( 1) HA > 1D, MA > 2D, AA > 1D The incidence of amblyopia were significantly increased and the level of stereopsis decreased. When anisometropia > 3D, the incidence of amblyopia increased to 100% and all the Titmus stereopsis were subnormal in each group.(2) The correlation between the degree of anisometropia and the severity of amblyopia was stronger than the correlation between the degree of anisometropia and the stereopsis. The correlation between the stereopsis and severity of amblyopia was stronger than the correlation between the level of stereopsis and the degree of anisometropia.更多还原