EFFICACY OF PRISM ADAPTATION IN ACQUIRED ESOTROPIA

回顾研究表明，50%的获得性外科患者 内斜视只需一次手术即可获得良好的眼球对齐效果。新证据 表明术前使用棱镜，良好的眼球对准可以 约85%的外科患者一次手术即可实现 后天性内斜视。多中心的、随机的、预期的、临床的 认真注意标准化和公正的结果 建议进行评估，以确定：1.综合效益 通过比较(A)棱镜适配响应者的棱镜适配程序 谁有手术的原始偏斜角来(B)那些患者 那些没有棱镜适应并为原始角度做手术的人 后天性内斜视患者是否对棱镜有反应 通过手术对适应的棱镜进行更准确的矫正 角度或原始偏差角度；3.患者是否有反应 通过发展新的稳定的偏离角度来棱镜适应有一个 比棱镜治疗无效的患者手术效果更好 适应；以及4.某些输入变量在预测中是否有用 哪些患者更有可能从棱镜适应中受益。 为了回答这些问题，一项双重随机研究 都是精心设计的。五分之三的患者将被挑选出来接受检查 术前棱镜适应。五分之二的患者会有 基于常规检查测量的交叉量的外科手术 技巧。在对棱镜有反应的患者中，有一半会 根据需要的棱镜数量进行手术以稳定眼球 而其余的将根据交叉量进行手术 最初测量的。 如果棱镜的适应确实带来了更成功的手术，它的采用可以 在实现减排的长期目标方面取得显著成效 获得性内斜视的治疗费用和发病率。 约2500例获得性内斜视的再手术 在美国的一年。如果可以通过以下方式减少三分之二 利用棱镜适配，总节省的美元将在 每年320万美元和480万美元。发病率也会同样是 减少手术并发症发生的比例，减少 从学校或工作中损失的时间，以及相当少的心理创伤 给病人的。

Retrospective studies indicate that 50% of surgical patients with acquired esotropia achieve good eye alignment with one surgery. New evidence indicates that with the preoperative use of prisms, good eye alignment can be achieved with one operation in approximately 85% of surgical patients with acquired esotropia. A multicenter, randomized, prospective, clinical trial with careful attention to standardization and unbiased outcome evaluation is proposed to determine: 1. The overall beneficial effect of the prism adaptation procedure by comparing (a) prism adaptation responders who have surgery for the original angle of deviation to (b) those patients who do not have prism adaptation and have surgery for the original angle of deviation; 2. Whether patients with acquired esotropia who respond to prism adaptation are more accurately corrected by operating for the prism adapted angle or the original angle of deviation; 3. Whether patients who respond to prism adaptation by developing a new stable angle of deviation have a better surgical result than patients who do not respond to prism adaptation; and 4. Whether certain input variables are useful in predicting which patients are more likely to benefit from prism adaptation. In an effort to answer these questions a double randomization study has been designed. Three-fifths of the patients will be selected to go through prism adaptation prior to surgery. Two-fifths of the patients will have surgery based on the amount of crossing measured using routine examination techniques. Of those patients who respond to the prisms, one-half will have surgery based on the amount of prism required to stabilize the deviation while the rest will have surgery based on the amount of crossing originally measured. If prism adaptation does lead to more successful surgery, its adoption can have a significant effect in meeting the long term objective of decreasing the cost and morbidity for the treatment of acquired esotropia. Approximately 2,500 reoperations for acquired esotropia are performed each year in the United States. If these could be reduced by two-thirds through utilization of prism adaptation, the total dollar saving would be between $3.2 million and $4.8 million per year. Morbidity would likewise be reduced with proportionally fewer operative complications occurring, less time lost from school or work, and considerably less psychological trauma to the patient.