Lai Y L, Jacoby R O, Jonas A M
Invest Ophthalmol Vis Sci. 1978 Jul;17(7):634-8.
Morphological changes in retinas of aging Fischer 344 rats were characterized. The numbers of photoreceptor cells gradually decreased as rats aged. The outer nuclear layer was 12 cells thick at 3 months, but was reduced to less than 8 cells by 18 months. The decrease of photoreceptor cells was more pronounced in rats housed under a light intensity of 32-ft-c than in rats housed under a light intensity of 1 ft-c. Inner and outer segments of surviving photoreceptor cells were morphologically normal. A new form of retinal degeneration was discovered in aged Fischer rats characterized by selective degeneration of peripheral retina. Degeneration was characterized by severe loss of photoreceptor cells in the far peripheral retina. Microcystoids were found in about 25% ofthe affected retinas, and the loss of photoreceptor cells was followed by proliferation and vascularization of the retinal pigment epithelium and disorganization of retinal structures. The incidence and severity of peripheral retinal degeneration increased with aged and prolonged exposure to comparatively high-intensity light. All Fischer rats ((5/5) housed under light intensity of 32 ft-c developed severe peripheral retinal degeneration by 24 months. Peripheral retinal degeneration was an age-related change but appeared to be exaggerated by ambient light.
对衰老的Fischer 344大鼠视网膜的形态学变化进行了表征。随着大鼠年龄的增长，光感受器细胞数量逐渐减少。3个月大时，外核层有12个细胞厚，但到18个月时减少到不足8个细胞。与饲养在1英尺烛光光照强度下的大鼠相比，饲养在32英尺烛光光照强度下的大鼠光感受器细胞减少更为明显。存活的光感受器细胞的内节和外节在形态上是正常的。在衰老的Fischer大鼠中发现了一种新的视网膜变性形式，其特征是周边视网膜选择性变性。变性的特征是最周边视网膜中的光感受器细胞严重缺失。在约25%受影响的视网膜中发现了微囊肿，光感受器细胞缺失后，视网膜色素上皮细胞增殖并血管化，视网膜结构紊乱。周边视网膜变性的发生率和严重程度随着年龄增长以及长期暴露于相对高强度的光照而增加。所有饲养在32英尺烛光光照强度下的Fischer大鼠（5/5）到24个月时都出现了严重的周边视网膜变性。周边视网膜变性是一种与年龄相关的变化，但似乎会因环境光而加剧。
