NCT03459092: BISS

Botox Instead of Strabismus Surgery (BISS)

Completed Phase 3 Last updated 7 November 2023

What this trial tests

Phase 3 trial testing Botulinum toxin type A in Acquired Esotropia in 63 participants. Completed in 31 July 2023.

Timeline

16 August 2018

Primary endpoint
31 July 2023

31 July 2023

Quick facts

Lead sponsor	Insel Gruppe AG, University Hospital Bern
Phase	Phase 3
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	63
Start date	16 August 2018
Primary completion	31 July 2023
Estimated completion	31 July 2023
Sites	8 locations across France, Switzerland

Drugs / interventions tested

• Botulinum toxin type A (BOTULINUM TOXIN TYPE A) — full drug profile →
• Strabismus surgery

Conditions studied

• Acquired Esotropia — all drugs for Acquired Esotropia →

Sponsor

Insel Gruppe AG, University Hospital Bern

Who can join

Adults 1 to 17, any sex, with Acquired Esotropia. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The purpose of the study is to evaluate if strabismus can be successfully treated requiring less surgical interventions with a Botox-based treatment regimen compared to a purely surgery based treatment regimen.

Experimental arm: Botulinum toxin injection in the horizontal extraocular muscles.

Control (active comparator) arm: Strabismus surgery on the horizontal extraocular muscles. No investigational product is used.

In Switzerland the standard procedure for treating large angle esotropia is surgery, which is performed on the horizontal eye muscles that may be either recessed or shortened leading to reduced or increased muscle function respectively.

As an alternative to strabismus surgery, botulinum toxin (Botox) can be applied in extraocular muscles. Botox prevents the release of acetylcholine in the synaptic cleft and thereby blocks the neuromuscular transmission thus inducing a palsy.

Current evidence on the use of Botox in strabismus is incoherent, is poorly supported by basic research findings and leaves dedicated clinicians in the dark. The objective is to shed light into this field of clinical research, which may help to guide future pediatric ophthalmologists in their management of strabismic patients. In a best case scenario, the results from this trial will prevent strabismus operation for many children with acquired large angle esotropia.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Botulinum toxin for the treatment of strabismus.
   Bort-Martí AR, Rowe FJ, Ruiz Sifre L, Ng SM, et al · · 2023 · cited 13× · PMID 36916692 · DOI 10.1002/14651858.cd006499.pub5
2. Interventions for infantile esotropia.
   Mehner L, Ng SM, Singh J. · · 2023 · cited 6× · PMID 36645238 · DOI 10.1002/14651858.cd004917.pub4