The objectives of the present work were to assess by spectral domain optical coherence tomography (OCT) the changes in thickness of the outer nuclear layer (ONL), the ONL + photoreceptor inner segment (IS), and the retinal thickness, as a function of age in the normal canine retina. OCT retinal scans extending from the edge of the optic nerve head (ONH) along the superior and inferior meridians were captured in both eyes of 17 normal dogs at age ranging from 4 to 119 weeks. The different parameters along the superior and the inferior regions were determined following manual segmentation using the Heidelberg Eye Explorer software. Changes in thickness with age were modeled using one-phase exponential decay models. In vivo OCT imaging results showed no interocular statistically significant differences in ONL, ONL + IS, and retinal thickness at any age. All three parameters were however found to be statistically significantly thicker in the superior vs inferior retina. A rapid thinning of the three layers occurs in both the superior and inferior retina between 4 and 12 weeks of age, before reaching a plateau at around 20 weeks of age. In conclusion, the ONL, ONL + IS, and retinal thickness of the normal canine retina decrease significantly during the first three postnatal months, and is likely attributed to an overall increase in the eye volume and tangential dispersion of the photoreceptor since early photoreceptor developmental cell death is very limited at that age. Establishment of the natural history of ONL, ONL + IS, and retinal thinning will allow a more accurate assessment of the progression of a retinal degenerative condition as well as facilitate the detection of positive rescue effect of novel retinal therapies evaluated in this large animal model.

中文翻译：

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产后犬视网膜厚度的体内纵向变化。

本研究的目的是通过光谱域光学相干断层扫描（OCT）评估外核层（ONL），ONL +感光体内部部分（IS）和视网膜厚度的厚度变化，作为正常犬视网膜的年龄。在年龄从4到119周不等的17只正常犬的两只眼睛中，捕获了从视神经头（ONH）边缘沿上，下子午线延伸的OCT视网膜扫描。在使用Heidelberg Eye Explorer软件进行手动分割之后，确定了沿上方和下方区域的不同参数。使用一相指数衰减模型来模拟厚度随年龄的变化。体内OCT成像结果显示，ONL，ONL + IS，和任何年龄的视网膜厚度。然而，发现在视网膜上与下视网膜相比，这三个参数在统计学上都明显更厚。三层的快速变薄发生在4至12周龄的上下视网膜中，然后在20周龄左右达到稳定期。总之，正常犬视网膜的ONL，ONL + IS和视网膜厚度在出生后的前三个月显着降低，这很可能归因于早期感光器发育细胞后，感光器的眼部体积和切向弥散总体增加了在那个年龄，死亡非常有限。建立ONL，ONL + IS，