Clinical trial NCT03895632: Eye Muscle Needle Electromyogram (EMu) Study
Official title: A Data Collection and Analysis Pilot Study to Indicate Preliminary Characterisation of the Electromyogram Signal in Relation to Needle Position With Respect to the Extraocular Muscles, as Observed During Electromyogram Needle Guided Treatment of Strabismus in Adults
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Strabismus
Keywords: Extraocular muscle
Electromyogram
Monopolar
Needle guidance
Botulinum toxin
Strabismus
Lead sponsor: Liverpool University Hospitals NHS Foundation Trust
Sponsor class: OTHER_GOV
Collaborators: name: Manchester University NHS Foundation Trust
First posted: 2019-03-29
Enrollment: 25
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with strabismus being treated with injections of Botulinum toxin.

Brief summary: In some cases, strabismus, or squint, is treated with injections of Botulinum toxin (BTX) to temporarily relax the eye muscle responsible for causing the eye to be pulled to one side. Due to the deep location of the muscles, electromyogram (EMG) needle guidance is used to help ensure the toxin is delivered accurately. EMG needle guidance involves listening to the EMG signal from the tip of the delivery needle - when the needle is in the right place a sound akin to "rain on a tin roof" is heard and the BTX can be injected.

From previous research, clearly clinicians want to improve the technology of this procedure and increase the treatment efficacy and repeatability. After all, the current procedure is imprecise and subjective for what is a small target, with the eye muscles being around 2.5 mm to 4.7 mm in diameter. There may also be an increase in the likelihood of side effects such as droopy eyelids when the toxin spreads beyond the target muscle.

There is a strong need for new knowledge to improve EMG needle guidance in this context. It is hypothesised that the EMG signal could be cleaned and mined for information in real time during the procedure, thus providing the clinician with better information to guide the positioning of the needle before injecting. This pilot study will deliver the knowledge essential to indicate the feasibility of doing this. If feasible, this study will inform a full study with the aim of benefitting patients by allowing new technology to be developed to improve the treatment of strabismus with BTX.


Eligibility criteria: Inclusion Criteria:

i. Adults undergoing planned, routine EMG needle guided BTX injection into either lateral or medial rectus muscle for the treatment of strabismus.

ii. Patients being treated by Mr Yagan.

Exclusion Criteria:

- Patients with Chronic progressive external ophthalmoplegia (CPEO) are excluded; a highly attenuated EMG signal is expected.

Primary outcomes:
measure: α (Slope) Parameter of the Electromyogram (EMG) Signal Power Spectral Density (PSD) Plot as Needle Approaches Then Enters Muscle.
timeFrame: Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
Secondary outcomes:
measure: Clinical Score of EMG Change
timeFrame: Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
measure: Clinical Score of Needle Placement Accuracy
timeFrame: Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
measure: Clinical Score of EMG Quality.
timeFrame: Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
measure: Post-treatment Angle of Deviation
timeFrame: 2 weeks
Other outcomes:
Locations:
city: Manchester
country: United Kingdom
facility: Manchester Royal Eye Hospital
Study officials:
affiliation: Liverpool University Hospitals NHS Foundation Trust
name: Tristan G Payne, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Pinheiro, J. & Bates, D. (2000) Mixed-Effects Models in S and S-PLUS. Statistics and Computing. New York, NY, USA: Springer-Verlag