多巴胺对兔实验性形觉剥夺性近视形成的影响

目的　研究多巴胺对实验性近视形成的影响.方法　7日龄幼兔52只，分A,B,C,3组.A组20只，单纯缝合眼睑；B组16只，缝合眼睑+玻璃体内注射多巴胺；C组16只，缝合眼睑+玻璃体注射生理盐水.均以右眼为实验眼，左眼为对照眼.第60日用A超测量每组双眼的前房深度、晶体厚度、玻璃体腔长度和眼轴长度，并计算玻璃体腔长度／眼轴长度，同时进行病理学观察.结果　A，C两组中实验眼的玻璃体腔长度、眼轴长度和玻璃体腔长度／眼轴长度分别为(7.9±0.6)mm,(15.4±0.6)mm,0.52±0.03;(7.3±0.5)mm,(15.1±0.7)mm,0.49±0.02；对照眼则为(7.2±0.8)mm,(14.5±0.7)mm,0.48±0.02;(6.8±0.4)mm,(14.6±0.6)mm,0.46±0.02.两眼间的差异有高度显著的统计学意义(P<0.001)，前房深度和晶体厚度无统计学差异，而B组均无统计学差异.巩膜胶原纤维在A,C两组中明显变细，而在B组中改变较轻.结论　形觉剥夺能导致眼球的轴性延长，玻璃体腔延长和VCL/AL增大是其形态学原因，巩膜纤维的变细、延长是其病理学原因之一，而多巴胺能部分阻止这些改变.

Effects of dopamine on experimentally form deprived myopia in rabbits

AIM　To study effects of dopamine on form deprived myopia. [ WTHZ〗METHODS　Fi fty-two of seven-day-old neonatal rabbits were divided into group A, B and C and monocularly deprived of pattern vision by suturation of right eyelids. I n group A (n=20), no drug was used, while rabbits in group B and C received a series of intravitreal injection of dopamine (n=16) or saline vehicle (n =16) with MD, respectively, the left eye were employed as control groups. Anterior chamb er depth (ACD), lenticular thickness (LT), vitreous chamber length (VCL) and axi al length (AL) of each eye were determined by means of A-scan ultrasonography on day 60, VCL/AL was calculated and pathologic changes were also observed. RESULTS　VCL, AL and VCL/AL of deprived eyes in group A and C were ( 7.9±0.6) mm, (15.4±0.6) mm, 0.52±0.03; (7.3±0.5) mm, (15.1±0.7) mm, 0.49±0 .02; yet those of control eyes were (7.2±0.8) mm, (14.5±0.7) mm, 0.48±0.02; (6.8±0.4) mm, (14.6±0.6 ) mm, 0.46±0.02. VCL, AL and VCL/AL but not ACD and LT of deprived eyes showed a significant di fference in group A and C (P<0.001), yet these did not show any difference i n group B. Scleral collagen fibres of deprived eyes were markedly thinner in g roup A and C, but were less in group B. CONCLUSION　Form depriva tion can induce axial elongation, longer vitreous chamber, higher VCL/AL and thinner scleral fib re do play a crucial role in the onset of myopia, while dopamine can partly bloc k these changes.