Smith E L, Hung L F, Harwerth R S
College of Optometry, University of Houston, Houston, Texas, USA.
Invest Ophthalmol Vis Sci. 2000 Nov;41(12):3775-81.
To determine whether the depth of monocular form-deprivation amblyopia is dependent on the degree of retinal image degradation.
Chronic monocular form deprivation was produced in nine infant rhesus monkeys by securing one of three different strengths of diffuser spectacle lenses in front of the treated eye and a clear zero-powered lens in front of the fellow eye. Three infant monkeys reared with plano lenses in front of both eyes provided control data. The treatment lenses were worn continuously from approximately 3 weeks of age for periods ranging between 11 and 19 weeks. When the monkeys were approximately 18 months of age, psychophysical procedures were used to measure the effects of the rearing procedures on the spatial contrast sensitivity function for each eye.
The treated eyes of all nine diffuser-reared monkeys showed contrast sensitivity deficits that were indicative of amblyopia. On average, the interocular grating acuity difference increased systematically from 0.6 octaves for the weakest diffuser lens to 2.3 +/- 0.7 and 3.5 +/- 0.8 octaves for the intermediate and strongest diffuser lenses, respectively. There was a close correspondence between the magnitude of the amblyopic deficits and the reduction in retinal image contrast produced by the diffuser lenses.
The results demonstrate that the depth of monocular, nonstrabismic amblyopia is strongly influenced by the degree of retinal image degradation experienced early in life.
确定单眼形觉剥夺性弱视的严重程度是否取决于视网膜图像退化的程度。
通过在受试眼前固定三种不同强度的漫射眼镜片之一，并在对侧眼前固定一个透明的零屈光度镜片，在9只幼年恒河猴中造成慢性单眼形觉剥夺。3只双眼佩戴平光镜饲养的幼年猴子提供对照数据。治疗镜片从大约3周龄开始连续佩戴11至19周。当猴子大约18个月大时，采用心理物理学方法测量饲养过程对每只眼睛空间对比敏感度函数的影响。
所有9只佩戴漫射眼镜片饲养的猴子的受试眼均表现出对比敏感度缺陷，表明存在弱视。平均而言，双眼光栅视力差异从最弱漫射镜片的0.6倍频程系统性增加到中间强度和最强漫射镜片的2.3±0.7倍频程和3.5±0.8倍频程。弱视缺陷的严重程度与漫射镜片导致的视网膜图像对比度降低密切相关。
结果表明，单眼、非斜视性弱视的严重程度受到生命早期经历的视网膜图像退化程度的强烈影响。
