Detailed anatomy of the abducens nerve in the lateral rectus muscle

Abstract

The aims of this study were to elucidate the detailed anatomy of the abducens nerve in the lateral rectus muscle (LRM) and the intramuscular innervation pattern using Sihler staining. In this cohort study, 32 eyes of 16 cadavers were assessed. Dissection was performed from the LRM origin to its insertion. The following distances were measured: from LRM insertion to the bifurcation point of the abducens nerve, from LRM insertion to the entry site of the superior branch or inferior branch, from the upper border of the LRM to the entry site of the superior branch, from the lower border of LRM to the entry site of inferior branch, and the widths of the main trunk and superior and inferior branches. The single trunk of the abducens nerve divided into two branches 37 mm from insertion of the LRM, and 22 of 32 (68.8%) orbits showed only two superior and inferior branches with no subdivision. The superior branch entered the LRM more anteriorly (P = 0.037) and the superior branch was thinner than the inferior branch (P = 0.040). The most distally located intramuscular nerve ending was observed at 52.9 ± 3.5% of the length of each muscle. Non-overlap between the superior and inferior intramuscular arborization of the nerve was detected in 27 of 32 cases (84.4%). Five cases (15.6%) showed definite overlap of the superior and inferior zones. This study revealed the detailed anatomy of the abducens nerve in the LRM and provides helpful information to understand abducens nerve palsy. Clin. Anat. 30:873-877, 2017. © 2017 Wiley Periodicals, Inc.

Intramuscular innervation of the lateral rectus muscle evaluated using sihler's staining technique: Potential application to strabismus surgery

“…In our study, the same distance had a mean of 37.38 mm (SD = 6.21 mm). Nam et al () also noted that the superior group of the abducens nerve subbranches entered the lateral rectus muscle more anteriorly than did the inferior group, and we observed the same relations in our study.…”

“…In their study, the muscle's mean length was 46.0 mm long, while it was 48.73 mm (SD = 1.03 mm) in ours. Nam et al (), who investigated the abducens nerve's detailed anatomy in the lateral rectus muscle, found that the single trunk of the abducens nerve divided into two branches 37 mm from insertion in the lateral rectus muscle. In our study, the same distance had a mean of 37.38 mm (SD = 6.21 mm).…”

Normal Anatomy and Anomalies of the Rectus Extraocular Muscles in Human: A Review of the Recent Data and Findings

“…Lateral movement of the eyeball is the primary function of the LR [1,2,8]. However, the recent studies indicate the complex activity of the LR, with the existence of the functional compartments (zones) within the muscle, which may be activated selectively depending on the type and phase of movement [2][3][4][17][18][19][20][21][22].…”

“…e statement of Farzavandi [1], who concluded that "An intimate knowledge of anatomy, including the extraocular muscles, periocular fascia, and orbit, is necessary to be an accomplished strabismus surgeon," became a motto of the presented review. Development of modern surgical techniques is associated with the need for a thorough knowledge of surgical anatomy and, in the case of ophthalmologic surgery, also functional aspects of extraocular muscles [1][2][3][4][5][6]. However, getting familiar with the numerous data that appear in various scientific journals may be difficult and time consuming.…”

“…Particular attention was paid to the presentation of detailed and structured data on the gross anatomy of the ERMs, including their attachments, measurements, anatomical relationships, vascularization, and innervation. is issue of ERMs innervation was described in detail, including the recent research that has been carried out on human material using advanced anatomical techniques such as Sihler's technique of the whole mount nerve staining [2][3][4][5][6].…”