A comparative multicentric long-term study of un-augmented modified Nishida procedure vs augmentation in unilateral sixth nerve palsy

Outcomes of "a new modification of Jensen technique combined with medial rectus recession" in patients with complete sixth cranial nerve palsy

BACKGROUND

To report the outcomes of "our modified Jensen technique" for treating esotropia in cases with complete sixth cranial nerve (CN VI) palsy.

METHODS

This study is a 30-year case series of isolated complete CN VI palsy who underwent combined medial rectus recession and our modified Jensen operation. We modified the original technique by anchoring the muscle-unifying sutures to the sclera near the equator using a non-absorbable suture. Major outcomes such as postoperative diplopia, face turn, horizontal and vertical eye deviations, and abduction limitation were assessed. Successful surgery was defined as orthotropia or esotropia equal to or less than 8 prism diopters (PD) and the absence of any vertical deviation.

RESULTS

Fifty-three cases with a mean age of 28 years old were included in this study. The male-to-female ratio was 3 to 1. Forty-five cases (85%) presented with unilateral palsy, whereas 8 patients (15%) had bilateral palsy. Trauma was the most common etiology (85%). Diplopia or face turn, presented in 42 patients before the operation, remained in seven cases after the operation. Primary position esotropia, which was the main complaint in all patients, decreased from 49 PD to 4 PD in unilateral palsy and from 101 PD to 10 PD in bilateral palsy. The mean reduction of abduction deficit was 1.78 in unilateral and 1.75 in bilateral palsy. The success rate was 76% in unilateral and 62% in bilateral palsy.

CONCLUSION

Our modified Jensen operation was effective in treating patients with complete CN VI palsy, producing no significant permanent complications.

Surgical management of chronic sixth cranial nerve palsy: case report and literature review

Background

Esotropia resulting from sixth cranial nerve palsy can substantially impact an individual's visual acuity and overall quality of life. If the condition does not resolve in 6-10 months, surgical intervention may be necessary. Various muscle surgeries may be considered, with vertical rectus muscle transposition emerging as the primary option for treatment of complete palsy. However, this technique carries the risk of anterior segment ischemia and post-surgery deviations. Herein, we present a successful treatment of chronic complete sixth nerve palsy using a modified Nishida procedure, without splitting or tenotomy, and an adjunct botulinum toxin A (BTA) injection in the ipsilateral medial rectus muscle.

Case Presentation

A 59-year-old woman with a history of traumatic sixth nerve palsy had previously undergone horizontal muscle strabismus surgeries. Following multiple left medial rectus recessions, lateral rectus resection, and BTA injections, esotropia persisted. The worsening of her condition led to emotional distress and impaired social interaction. Initial examination revealed marked esotropia and limited left eye abduction. Magnetic resonance imaging (SIGNA MR750w, GE Healthcare, Waukesha, WI, USA) of the left eye revealed a contracted medial rectus muscle and substantial atrophy of the left lateral rectus muscle. A modified Nishida procedure was performed with an injection of 3 units of BTA into the ipsilateral medial rectus muscle, resulting in improved ocular alignment and stable findings after nine postoperative months. Furthermore, we supported our successful outcome with a summary of similar reported cases of sixth nerve palsy managed using the modified Nishida procedure with or without adjunctive procedures.

Conclusions

Following the modified Nishida procedure, the patient experienced a reduction in diplopia, improved ocular alignment and stability, and an increased binocular diplopia-free field. This case underscores the importance of an individualized approach to complex strabismus cases and highlights the modified Nishida procedure as a valuable tool in such circumstances. In the future, strabismus management will focus on refining personalized treatment and exploring innovative techniques for complex cases. Our success in using a combination of Nishida procedure and BTA injection should be further investigated in large-scale studies.

Golden Indications and an Overview on the Use of Botulinum Toxin in Strabismus

Botulinum toxin A (BTXA) is considered a pharmacological agent that may provide an alternative treatment to surgery in strabismus. It can be used as both a diagnostic and therapeutic agent in various concomitant, paralytic, and restrictive disorders. The major advantage of BTXA treatment is that it is non-invasive and does not impact the patient's chance for future surgery in case of an unfavorable response. In some selected disorders, BTXA has become the primary choice of treatment, whereas surgery is found to be more effective in others. Accumulated knowledge and experience have demonstrated that BTXA is more than merely an alternative treatment and has additional specific indications such as in unstable deviations and as an adjunct to surgery. Patients with recurrent deviations despite multiple surgeries are also good candidates for BTXA treatment. Although the major expectation is to obtain a permanent result, BTXA can also be used as a maintenance treatment. This paper mainly focuses on the current indications for the use of BTXA in strabismology, with special emphasis on ideal first-choice applications referred to as "golden indications," within the scope of the author's own experience with the use of BTXA over 30 years.