Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
Invest Ophthalmol Vis Sci. 2011 Jul 13;52(8):5226-32. doi: 10.1167/iovs.10-6307.
Mice with a targeted disruption of Brn3b (knockout Brn3b(-/-)) undergo the loss of a majority of retinal ganglion cells (RGCs) before birth. Spectral domain optical coherence tomography (SD-OCT) allows for the noninvasive examination of Brn3b(-/-) cellular loss in vivo.
The central retinas of Brn3b(-/-) and phenotypically wild-type (Brn3b(+/+) and Brn3b(±)) mice were imaged by SD-OCT. The combined nerve fiber layer (NFL) and inner plexiform layer (IPL) were manually segmented and thickness maps were generated. The results were confirmed by histologic and immunofluorescence cell counts of the RGC layer (RGCL) of the same retinas.
The combined NFL and IPL of the Brn3b(-/-) retinas were significantly thinner, and the histologic cell counts significantly lower, than those of the phenotypically wild-type retinas (paired t-test; P < 0.01 and P < 0.01, respectively). The combined NFL and IPL thickness and the histologic cell count correlated highly (R(2) = 0.9612). Immunofluorescence staining revealed significant RGC-specific loss in Brn3b(-/-) retinas (paired t-test; P < 0.01). The distribution of combined central NFL and IPL loss was not localized or sectorial.
The strong correlation between the combined layer thickness and histologic cell counts validates manual OCT segmentation as a method of monitoring cell loss in the RGCL. A retinal thickness map assessed if combined NFL and IPL thickness loss in Brn3b(-/-) eyes was topographically specific. Generalized RGC and combined NFL and IPL loss was observed in the Brn3b(-/-) retinas, in contrast to topographically specific RGC loss observed in glaucomatous DBA2/J eyes.
靶向破坏 Brn3b（Brn3b(-/-) 敲除）的小鼠在出生前会失去大部分视网膜神经节细胞（RGC）。光谱域光学相干断层扫描（SD-OCT）允许对 Brn3b(-/-) 细胞损失进行非侵入性检查。
通过 SD-OCT 对 Brn3b(-/-) 和表型野生型（Brn3b(+/+)和 Brn3b(±)）小鼠的中央视网膜进行成像。手动分割神经纤维层（NFL）和内丛状层（IPL）并生成厚度图。通过对相同视网膜的 RGC 层（RGCL）进行组织学和免疫荧光细胞计数来验证结果。
Brn3b(-/-) 视网膜的 NFL 和 IPL 厚度明显变薄，组织学细胞计数明显降低，明显低于表型野生型视网膜（配对 t 检验；P < 0.01 和 P < 0.01）。NFL 和 IPL 厚度的组合与组织学细胞计数高度相关（R(2) = 0.9612）。免疫荧光染色显示 Brn3b(-/-) 视网膜中存在明显的 RGC 特异性丢失（配对 t 检验；P < 0.01）。NFL 和 IPL 损失的组合分布不是局部或扇形的。
组合层厚度与组织学细胞计数之间的强相关性验证了手动 OCT 分割作为监测 RGCL 中细胞损失的方法。视网膜厚度图评估了 Brn3b(-/-) 眼中 NFL 和 IPL 厚度损失是否具有地形特异性。与观察到的青光眼 DBA2/J 眼中具有地形特异性的 RGC 损失相反，在 Brn3b(-/-) 视网膜中观察到广泛的 RGC 和 NFL 和 IPL 损失。
