散光眼与近视化关系的研究
眼视光学杂志 1999年第1期第1卷 论著
作者:吉红云 汪芳润 李 军 胡 磊 周晓东
单位:上海医科大学金山医院眼科(200540)
关键词:散光;正视化;近视;动物,实验;屈光,眼
摘 要 目的:了解生长发育期眼的散光与正视化及近视发生发展的关系。方法:检查4~7岁和10~16岁两组对象的屈光情况,部分病例随访3年以上,睫状肌麻痹下验光,角膜曲率计测角膜散光。随访3~12岁混合散光患儿21眼。鸡41只于出生次日行单眼角膜散光术,另眼对照,观察屈光及A超和游标卡尺测球径。结果:散光发生率为71.4%。4~7岁组中散光眼和无散光眼随访3年以上,平均远视屈光度分别降低+0.94±0.86D和+0.58±0.48D,差异明显(t=2.57,P<0.01)。10~16岁组中散光眼和无散光眼随访3年以上平均近视屈光度分别增加-1.21±0.63D和-0.625±0.29D,差异显著(t=5.85,P<0.001)。混合散光眼3年后多转变为复性近视散光。动物人工角膜散光可诱发低度近视屈光,与对照眼比较差异有极显著意义。鸡实验眼轴长多大于对照眼,组织病理学无明显改变。结论:散光在人及动物生长发育期可加速眼的正视化及诱发眼的近视化。
Study on the relationship between astigmatic eye and myopization Ji Hongyun, Wang Fangrun, Li Jun,et al.Department of Ophthalmology, Jinshan Hospital, Shanghai Medical University, Shanghai 200540
Abstract Objective:To investigate the relationship between astigmatism and emmetropization as well as the the development of myopia in the period of growth.Methods: The groups of 4 to 7 year old hyperopic children,10 to 16 year old myopic teenagers and 3 to 12 year old children with mixed astigmatism were examined with keratometry and retinoscopy,part of which were followed up for more than 3 years.Monocular corneal astigmatism was induced in 41 newly hatched chicks with peripheral corneal incision and compression suture.Refractive status and ocular dimensions were measured .The treated eyes of chicks were enucleated and examined histopathologically.Results: The prevalence of astigmatism is 71.4%. In 4 to 7 year old group, the mean decrease of hyperopic refractive value was +0.94±0.86D in hyperopic astigmatic eyes, while +0.58±0.48D in simple hyperopic ones with significant difference(t=2.57,P<0.01) between these two groups. In 10 to 16 year old group, the mean increase of myopic refractive value was -1.21±0.63D in myopic astigmatic eyes, while -0.63±0.29D in simple myopic ones with significant difference (t=5.85,P<0.001)between these two groups.The majority of mixed astigmatic eyes changed into myopic astigmatism after 3 years. Chicken eyes treated with corneal astigmatism showed more myopic refractive error,longer axial length and larger ocular volume than untreated eyes without significant pathological changes except for slight corneal scar.Conclusion:Astigmatism can accelerate emmetropization and induce myopization in both human and animal during the period of growth.
Key words Astigmatism Emmetropization Myopization Experiment,animal Refraction,eye
在人眼发育过程中,屈光变化是主要内容,从最初的远视到日后的正视,及至近视化改变,可受多种因素的影响。了解这些或某一因素的存在,认识其作用规律,并求实现对屈光改变的人为控制,是近视眼防治研究的最终目的之一。有鉴于此,本研究在前阶段工作的基础上,集中通过人眼的屈光状态变化分析(动态和横断面观察)及动物实验,进一步了解散光与近视发生发展的关系。
1 材料和方法
1.1 研究对象:①普查4~7岁儿童1082人,2160眼。复查(间隔≥3年)98只眼。②10~16岁屈光门诊患儿712只眼。复查(间隔≥3年)86只眼。③实验动物:鸡41只,出生次日单眼行角膜散光术,另眼对照。
1.2 观察项目:①远近视力(国际标准视力表),②眼屈光度(YZ-24带状光检影镜),均为睫状肌麻痹(阿托品)下验光记录,③角膜曲率(Canon Auto Keratometer K-1),④眼轴(Storz A/B Compuscan及游标卡尺)。
1.3 动物实验:取鸡(品种为AA-CS)41只,于孵化一日即行实验。氯氨酮肌注麻醉及丁卡因眼表面麻醉,开睑器暴露眼球。取双面刀片一小碎片固定于显微持针钳上,刀片出口长度为0.3mm(用10倍的角膜顶点测定仪测定)。术者一手持镊,固定眼球,一手持刀,显微镜下于上方或下方垂直于角膜作一横向水平切口,长约2mm,深约0.3mm,10-0线缝合一针,收紧结扎可使角膜表面形成明显的散光。一眼处理,另眼对照。实验后56天处死。先后测定活体与离体的眼球前后径、水平径、垂直径及玻璃体腔径,并计算眼球体积及行病理组织学检查。
1.4 操作按常规由固定人员进行。一鸡一卡,统计学处理采用微机MINITAB及EPI5软件处理系统。
2 结果
2.1 儿童眼散光及屈光变化
4~7岁儿童普查1 082名,2 160只眼中散光≥0.5D者有1 542只眼,占71.4%,循规性散光占大多数。≥3年后复查98眼结果见表1。散光值多随年龄的增长而降低,52眼平均降低0.42±0.84D。轴向绝大多数改变在0°~15°之间,个别可相差30°
表1 散光眼和无散光眼屈光测定三年变化比较 (D,±s)
|
眼数 |
初次验光 |
三年复测 |
远视屈光降低 |
散 光 眼 |
52 |
+2.19±1.05 |
+1.31±1.42 |
0.94±0.86** |
无散光眼 |
46 |
+1.90±0.40 |
+1.31±0.63 |
0.58±0.48 |
与无散光眼比,**t=2.57,P<0.01
2.2 近视病例屈光度变化观察 共86眼(10~16岁)验光诊断为近视患者,其中原有散光(复性近视散光和单纯近视散光)48眼,无散光(单纯近视)38眼。≥3年后(>18岁)复查见近视屈光度均有增加,见表2。
表2 近视屈光变化随访测定比较(D,±s)
|
眼数 |
初次验光 |
末次测定 |
近视屈光增加 |
散光眼 |
48 |
-1.73±0.92 |
-2.96±1.08 |
1.21±0.63***
|
无散光眼 |
38 |
-1.64±0.84 |
-2.27±0.82 |
0.63±0.29 |
与无散光眼比,***t=5.85,P<0.001
2.3 混合散光患儿屈光变化观察 17名儿童(21只眼)3~12岁时初测屈光为混合散光者(远视基础,近视散光), 3年后复查发现, 随着年龄增长,眼不断发育而均渐近视化,表现为原有基础远视不断降低或消失, 其中除1只眼仍为混合散光外,16只眼变为复性近视散光,2只眼为单纯近视散光,2只眼为单纯近视。21只眼屈光度平均改变1.75D。 原近视散光度逐步降低, 21只眼平均降低0.29±0.11D,降低的散光值约等于垂直轴上的近视增加值。如幼时为+1.00DS/-3.00DC×180,日后可呈现为-1.00DS/-2.00DC×180,或-2.00DS/-1.00DC×180的屈光状态。
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