Background/aims Anterior segment ischaemia (ASI) is a rare but serious complication of strabismus surgery, which may be caused by damage to the anterior ciliary arteries that run along the rectus muscles. To avoid ASI, clinical praxis is to operate on a maximum of two rectus muscles at a time. The aim of this study was to perform a detailed study of the contribution of the four ocular rectus muscles to the perfusion of the anterior segment using laser speckle contrast imaging (LSCI). Methods The four rectus muscles were successively detached during enucleation in nine patients with suspected uveal melanoma. Perfusion of the anterior segment was monitored with LSCI during the detachment of each of the rectus muscles, and after the ophthalmic artery had been severed. Results Perfusion of the anterior segment, measured in the paralimbal tissue, decreased gradually as the four rectus muscles were detached, showing a decrease to 98% when the first (lateral rectus) muscle was detached, to 88% when the second (medial rectus), and 69% when the third (inferior rectus) muscles were detached. The decrease was more pronounced and statistically significant when the fourth (superior rectus) muscle was detached (to 28%, p=0.0102). Conclusion LSCI is a valuable perfusion monitoring tool, as it has the capability to visualise the gradual decrease in anterior segment perfusion as the rectus muscles are successively detached. Further studies are needed to determine how many rectus muscles can be safely detached during strabismus surgery without risking ASI. Data are available on reasonable request.

中文翻译：

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详细测量四块眼外直肌对眼前节灌注的贡献


背景/目的 眼前段缺血（ASI）是斜视手术的一种罕见但严重的并发症，可能是由于沿着直肌运行的前睫状动脉受损引起的。为了避免 ASI，临床实践是一次最多对两块直肌进行手术。本研究的目的是使用激光散斑对比成像 (LSCI) 详细研究四块眼直肌对眼前节灌注的贡献。方法对9例疑似葡萄膜黑色素瘤患者，在剜除术中先后分离4块直肌。在每块直肌分离期间以及眼动脉被切断后，用 LSCI 监测眼前节的灌注。结果 随着四块直肌分离，在边缘组织中测量的眼前段灌注逐渐减少，当第一块（外直肌）分离时，血流减少至 98%，当第二块（内直肌）分离时，血流减少至 88% ，当第三块肌肉（下直肌）分离时，这一比例为 69%。当第四块（上直肌）分离时，这种减少更加明显且具有统计学意义（至 28%，p=0.0102）。结论 LSCI 是一种有价值的灌注监测工具，因为它能够可视化随着直肌的相继脱离而眼前节灌注逐渐减少。需要进一步的研究来确定在斜视手术期间可以安全分离多少直肌而不会有 ASI 的风险。可根据合理要求提供数据。