Functional-Morphological Studies for Aging Changes in Ocular Accommodation

研究了眼内睫状肌和晶体透镜（透镜）的形态学变化与老视的关系。1)客观脑电图的图形分析表明，阶跃刺激的脑电波幅比连续刺激大，连续刺激的脑电波幅在35 ~ 39岁和40 ~ 44岁之间明显降低。2)透镜厚度随年龄增长和收缩而不断增加，50岁时的厚度与20岁时收缩的透镜厚度相同。随着年龄的增长，前房深度持续下降。3)随着年龄的增长，人和猴的睫状肌的大小减少，结缔组织比例增加。这两个物种的环形肌纤维在人眼中增加了70岁的比例，在猴子中增加了20岁的比例。4)毛果芸香碱的适应性收缩引起肌肉宽度的增加和睫状肌向猴眼的轴向和前向的移位。5)人和猴睫状肌细胞内脂褐素颗粒的数量随年龄增长而增加。6）冷冻断裂技术显示猴睫状肌细胞内肌丝与细胞膜和核膜有直接联系。7)新形成的皮质透镜纤维的相对比例增加，提示透镜弹性随年龄增长而降低的可能性。

Morphological change of the ciliary muscle and crystalline lens(lens)were investigated in relation to the prebyopia. 1)Pattern analysis of objective accommodogram indicated larger accommodative amplitude by step stimuli than by continuous stimuli and marked decrease of the amplitude between 35 to 39 and 40 to 44 years of age by continuous stimuli. 2)The lens showed continuous increases of thickness with age and by accommodative contraction and the thickness in the fifties was as same as the accommodatively contracted lens in the twenties. The anterior chamber continuously decreased in depth with age. 3)Human and monkey ciliary muscles decreased their size and increased connective tissue ratio with age. The circular muscle fiber of both species increased their ratio by 70 years of old in the human-eye and 20 years of old in the monkey. 4)Accomodative contraction by pilocarpine caused increases of the muscle width and shifting of the ciliary muscle toward the axial-and-anterior direction of the monkey eye. 5)Lipofuscin granules in the human and monkey ciliary muscle cell showed age-dependent increase in number. 6)Freeze-fracture technique disclosed that myofilaments in the monkey ciliary muscle cell had direct connection with cell and nuclear membranes. 7)Increased relative ratio of newly formed cortical lens fibers suggested a possibility which might cause decrease of the lens elastisity with age.