The role of surgical factors eliciting oculocardiac reflex of patients undergoing orbital tumor surgery: a retrospective study

PURPOSE

Orbital tumors are an interdisciplinary disease, and surgery is one of the main treatment methods. The oculocardiac reflex (OCR) is a condition of surgery for orbital tumors. The aim of this study was to investigate whether there is an association between many surgical factors and the incidence of OCR in orbital tumor surgery.

METHODS

Comparisons were made between patients with and without OCR using the Mann-Whitney test, Fisher's exact test, and Chi-square test. When comparing multiple groups (groups > 2), to explain which two groups had differences, post hoc testing was used for analysis, and the differences between groups were judged according to the adjusted standardized residuals.

RESULTS

The results showed that the incidence of intraoperative OCR was different based on the different exposed operative field locations (p = 0.021). The OCR incidence in those with lesions involving the orbital apex and lesions adhering to extraocular muscles was higher than that of others (p < 0.001 and p = 0.003). In addition, multivariate logistic regression analysis revealed that orbital apex involvement and extraocular muscle adhesion were highly associated with a higher incidence of OCR (p < 0.001 and p = 0.013), while the operative field located in the lateral-superior orbit was highly associated with a lower incidence of OCR (p = 0.029).

CONCLUSION

In orbital tumor surgery under general anesthesia, lesions involving the orbital apex and lesion adhesion to the extraocular muscles were independent risk factors for OCR, and an operative field located in the lateral-superior orbit was a protective factor for OCR.

Medial Rectus Plication in the Management of Dissociated Horizontal Deviation: Case Report and Literature Review

Purpose

To report a case of medial rectus plication for the management of dissociated horizontal deviation (DHD).

Methods

We introduce medial rectus plication for improving the control of exoshift of DHD.

Results

A 20-year-old woman with a chief complaint of left eye outward deviation since childhood was referred to the strabismus clinic. The diagnosis of DHD was made according to the detection of asymmetric slow abduction of the left eye (50 prism diopter) during visual inattention or cover testing. The left lateral rectus (LR) was recessed 8 mm with a posterior fixation suture (PFS). In the early postoperative period, the control of DHD improved; however, after 6 months, the patient and her parents complained of frequent observation of the exoshift of the left eye (30 prism diopter). For better control of DHD, medial rectus plication (5 mm) of the left eye was considered the second operation. After 12 months of follow-up, the control of deviation improved, and there was no manifest deviation.

Conclusions

The literature's recommended procedure for unilateral DHD without a duction deficit is to perform a unilateral LR muscle recession. Some authors have proposed adding PFS to augment the effect of LR recessions. Although recurrence may occur, medial rectus plication can be considered one of the reversible options and can be used in recurrences of DHD after the first surgical procedure.

[Long term outcomes of botulinum toxin injections in infantile esotropia]

PURPOSE

To evaluate long terms outcomes of botulinum toxin in infantile esotropia by measuring the amount of microtropia 24 months after injection. Secondary purpose was to identify predictive factors of microtropia.

METHODS

A retrospective, single-center study was performed at the university medical center in Bordeaux between 2001 and 2018, including all patients with infantile esotropia greater than 20 D. All patients received 5 or 7,5 IU of botulinum toxin A in each medial rectus, once or twice depending on the angle of deviation after the first injection and after wearing full optical correction at least two months. We noted the angle at 1, 6, 12 and 24 months, the occurrence of any complications and the need for later strabismus surgery. The primary endpoint was the achievement of a microtropia less than 8 diopters (D) at 24 months post-injection. We evaluated the predictive factors for microtropia with a Fischer's test.

RESULTS

We included 30 patients with esotropia greater than 20 D. The mean follow-up after injection was 48 months ±30. The mean age was 16.24 months (7-29 months) with a female predominance in the population (SR=0.43). The mean pre-injection deviation was 41.25±12.17 D. The majority of patients were mildly (40%) or moderately (40%) hyperopic. At 24 months, 46.7% microtropias were obtained (95% CI: 28.9%-64.5%). The change in mean angle at 1, 6, 12 and 24 months post-injection was -8.57±25.21 D; 14.48±13.40 D; 18.38±12.07 D and 21.23±14.97 D, respectively. No factors were predictive of microtropia. Of the 30 children, 3 had transient ptosis requiring strips and 12 showed an exotropia at 1 month. All complications were self-limited and without consequences. 3 children had a second injection of botulinum toxin, which in 2/3 of the cases resulted in a long-lasting microtropia. 26.7% (n=8) of the children underwent secondary surgery. Obtaining a microtropia 24 months after injection statistically significantly reduced the need for secondary strabismus surgery: 92.9% P=0.039% CI 95% (0.002; 1.0606).

CONCLUSION

Botulinum toxin appears to be a less invasive and more conservative alternative to surgery in children with infantile esotropia. In 46.7% of cases, microtropia is achieved. An improvement was noted in 90% (n=27) of the children with a reduction of half (21.23 D) of the mean post-injection angle at 24 months. When effective, it significantly reduces the need for secondary surgery.

Minimal invasive vertical muscle transposition for the treatment of large angle exotropia due to congenital medial rectus hypoplasia: Case Report and Literature Review

Reports of isolated anomalies of the medial rectus (MR) muscle in literature are sparse. It has been identified as a subtype of congenital cranial dysinnervation disorder that affects the normal development of brainstem motor neurons. Herein, we report a 37-year-old male presented with large-angle exotropia since the birth of right eye with palpebral fissure widening. On examination of ocular movements, there was -6 limitation of adduction. There was no limitation in other ocular movements. In the preoperative CT scan, all extraocular muscles were present. He underwent surgery in right eye. Intraoperatively in the site of medial rectus, we found an empty sheath without muscle fibers indicating medial rectus hypoplasia. The width of muscle insertion was normal. Surgery consisted of lateral rectus muscle recession 10 mm in hang-back method and vertical muscle transposition procedure, by a modification of Nishida technique, in which the vector of superior and inferior recti was transposed medially by inserting non-absorbable sutures at nasal margins of muscles secured to sclera 8 mm posterior to medial rectus site without tenotomy or splitting. The deviation was decreased to less than 10 PD exotropia in primary position. The adduction was improved from -6 to -4. The palpebral fissure asymmetry was also corrected. Here, we also reviewed clinical features of all cases of medial rectus hypoplasia/aplasia in the literature and discussed surgical approaches. For vertical rectus transposition and horizontal muscle weakening, this technique has the advantages of being simpler and less traumatic to ocular tissues and unlike the traditional transposition procedures, there is no need for tenotomy and splitting.

Relationship of the Optic Nerve to the Medial Rectus Muscle During Endonasal Dissection of the Medial Intraconal Orbital Apex

BACKGROUND

Few studies have established surgical landmarks for endoscopic endonasal dissection of the intraconal orbital apex (OA).

OBJECTIVE

We describe the optic nerve (ON) anatomy and its relationships, as seen during a fully endoscopic, endonasal approach to the medial intraconal OA.

METHODS

The study question was approached through a cadaver dissection and a radiographic study. Four formalin-fixed, latex-injected cadaver heads were dissected using transnasal endoscopic techniques. Dissection was performed using 0 degree and 30 degree nasal endoscopes and standard endoscopic sinus surgical instrumentation. A bi-nostril 4-handed technique was used. The anatomy of 8 medial OAs was evaluated and recorded. As the radiographic portion, 100 consecutively enrolled patient magnetic resonance images were evaluated, with particular attention given to the relationship of the ON to the medial rectus muscle (MRM) in 200 orbits.

RESULTS

Intraconally, the ON consistently coursed along the superior half of the MRM. Interestingly, the nerve was more easily identified from a superior approach after retracting the MRM inferiorly. With the identification of the nerve at the OA, carrying the dissection of the medial OA was easily accomplished with the ON as the guiding landmark. The radiographic portion of this study revealed a consistent relationship between the superior edge of the ON and the MRM. This relationship was maintained in the orbital apex in 98.4%-100% of the orbits examined.

CONCLUSION

The superior edge of the optic nerve is consistently found coursing along the superior half of the MRM, facilitating facile identification and further dissection navigation.