远视性离焦对豚鼠屈光状态的影响

目的 观察不同方法形成的远视性离焦引起发育期豚鼠眼球屈光状态和眼轴长度的变化，探讨不同方法远视离焦视觉诱导的有效性以及高度离焦对眼轴异常发育的风险。设计 实验研究。研究对象18只6周龄雄性花色豚鼠。方法 将18只豚鼠随机分为3组：正常对照组（A组）3只，凹透镜诱导组（B组）10只，无晶状体眼诱导组（C组）5只。A组不做干预，B组右眼缝合镶有凹透镜（实验动物眼本身的屈光度基础上加-13.00 D）的眼罩3周，C组右眼于6周龄行晶状体针吸术。两组左眼均为对照眼。于实验前和诱导后3周（9周龄）分别检测双眼的屈光度、眼轴长度。对比实验前后和实验眼与对照眼屈光发育的差异，综合评估不同诱导方法的有效性。主要指标 等效球镜度数、眼轴长度。结果 诱导前，各组屈光度、眼轴长度差异均无统计学意义（P均＞0.05）。A组诱导前屈光度（2.83±0.29）D，眼轴（8.01±0.18）mm，3周后屈光度（2.17±0.29）D，眼轴（8.41±0.15）mm。B组诱导前屈光度（2.55±0.98）D，眼轴（8.15±0.24）mm；3周后屈光度（-0.50±0.67）D，眼轴（9.30±0.14）mm；诱导出（-2.83±0.80）D的相对近视，眼轴较诱导前增长（1.18±0.22）mm。C组针吸术后屈光度（35.25±2.06）D，眼轴（7.96±0.11）mm；3周后屈光度（29.75±1.70）D，眼轴（9.95±0.07）mm；诱导出（-5.50±0.58）D的相对近视，眼轴较诱导前增长（1.98±0.14）mm。B组、C组诱导眼眼轴长度增加和近视漂移比各自的对照眼和A组右眼均增加显著（P均＜0.05）。结论 发育期豚鼠对晶状体缺如和镶有高度负镜的眼罩诱导引起的远视离焦是敏感的，均有导致异常近视漂移和眼轴增长的作用。

Experimental study of the effects of hyperopic defocus induction on the refraction in guinea pigs

Objective  To observe the changes of the refractive state and axial length induced by two different hyperopic defocus methods in the infant guinea pigs; to discuss the sensitivity of guinea pigs to these two methods. Design Experimental study. Participants 18 male pigmented guinea pigs (age of 6 weeks). Method 18 pigmented guinea pigs (age of 6 weeks) were randomly assigned to 3 groups: normal control group (group A, 3 cases), Goggle myopia induction group (group B, 10 cases), aphakia induction group (group C, 5 cases). In the latter two groups, right eyes were used to be performed by the corresponding induced method, while left eyes were the control eyes. Refraction and axial lengths were examed before experiment and three weeks after induction. Compared the refractive developmental differences in the experimental eyes with the control eyes before and after the experiment, and comprehensively assessed the effectiveness of different methods of induction. Main Outcome Measures Axial lengths and refractive states. Results Before the inducement, the refrection and axial length were no significantly different among the three groups (P>0.05). Three weeks later, in comparison to the control eyes，the right eyes of group B and group C became more myopic (on average -2.83±0.80 D and-5.50±0.58 D, respectively) and elongated (on average 1.18±0.22 mm and 1.98±0.14 mm, respectively) (all P<0.05). Conclusions Aphakia and negative lens can interfere vision development and induce the myopic development  and axial growth in the infant guinea pigs.