Castanera de Molina A
Ophthalmology Institute, Barcelona, Spain.
Binocul Vis Strabismus Q. 1998;13(4):255-66.
To evaluate the ability of a computer assisted model of ocular motility, to reproduce this syndrome using known ocular anatomic biomechanical muscular parameters, and to hypothesize pathogenetic mechanisms deduced from clinical and laboratory experiences.
The manipulation of anatomic, elastic, contractile and innervational parameters available in the computer software program Orbit 1.6, were used to model: a) anatomic ocular and orbital parameters found in the 12 months old infant; b) static (biomechanical) changes measured intraoperatively in the extraocular muscles (medial and lateral rectus muscles) of infantile esotropes; and c) dynamic components of the horizontal deviation, including crossed fixation and bilateral limitation of abduction. Bilateral medial rectus recession surgery was also simulated on the completed model by moving backwards the insertions of both medial rectus muscles.
Small, fairly comitant, esotropic deviation were simulated using real data of the mechanical status of medial and lateral rectus muscles collected intraoperatively (length-tension measurements). The more typical large esotropic deviations with bilateral limitation of abduction of the congenital/infantile esotropia syndrome were only obtained when subtle modifications of the medial and lateral rectus muscles' thresholds to innervation were added to the anatomical-mechanical model. An orthotropic primary position binocular alignment with full rotations was obtained in this model following standard bilateral medial rectus recessions, showing surgical dose/response figures close to those usually found in the treatment of real cases of congenital/infantile esotropia.
This biomechanical computer-assisted model may provide a very useful tool not only to test new or different surgical procedures and dosages but also to explore different pathogenetic mechanisms.
评估一种计算机辅助眼球运动模型利用已知的眼部解剖生物力学肌肉参数重现该综合征的能力，并推测从临床和实验室经验中得出的发病机制。
利用计算机软件程序Orbit 1.6中可用的解剖、弹性、收缩和神经支配参数进行模拟：a）12个月大婴儿的眼部和眼眶解剖参数；b）在婴儿型内斜视的眼外肌（内直肌和外直肌）术中测量的静态（生物力学）变化；c）水平偏差的动态成分，包括交叉注视和外展双侧受限。通过向后移动双侧内直肌的附着点，还在完整模型上模拟了双侧内直肌后徙手术。
使用术中收集的内直肌和外直肌机械状态的实际数据（长度-张力测量）模拟出小的、相当共同性的内斜视偏差。只有当在内侧和外侧直肌的神经支配阈值上进行细微修改并添加到解剖-力学模型中时，才能获得先天性/婴儿型内斜视综合征更典型的大的内斜视偏差以及外展双侧受限。在该模型中，标准双侧内直肌后徙后获得了具有完全旋转的正交性第一眼位双眼对齐，显示出手术剂量/反应数据与先天性/婴儿型内斜视实际病例治疗中通常发现的数据接近。
这种生物力学计算机辅助模型不仅可以提供一个非常有用的工具来测试新的或不同的手术程序和剂量，还可以探索不同的发病机制。
