Eye Muscle Needle Electromyogram (EMu) Study

Strabismus Clinical Trial

— EMu  

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03895632
• Other study ID #: 5686
• Status: Completed
• Start date: February 20, 2019
• Est. completion date: May 30, 2019

Study information

• Verified date: January 2019
• Source: Liverpool University Hospitals NHS Foundation Trust
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: May 30, 2019
• Est. primary completion date: May 30, 2019
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

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.

Related Conditions & MeSH terms

• Strabismus

Locations

Country	Name	City	State
United Kingdom	Manchester Royal Eye Hospital	Manchester

Sponsors (2)

Lead Sponsor	Collaborator
Liverpool University Hospitals NHS Foundation Trust	Manchester University NHS Foundation Trust

Country where clinical trial is conducted

United Kingdom, 

References & Publications (1)

Pinheiro, J. & Bates, D. (2000) Mixed-Effects Models in S and S-PLUS. Statistics and Computing. New York, NY, USA: Springer-Verlag

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	a (Slope) Parameter of the Electromyogram (EMG) Signal Power Spectral Density (PSD) Plot as Needle Approaches Then Enters Muscle.	The continuous change in the EMG signal as the needle is (a) distal to, (b) approaches, and (c) enters, the target extraocular muscle.; Welch's periodogram estimator (Hamming window, 256-point FFT, 50% overlap) was applied to each of the three signal segments described above to obtain an estimate of the PSD of the signal. A robust linear model was fit to estimate the a (slope) parameter of each PSD plot.	Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
Secondary	Clinical Score of EMG Change	Clinician's score of the step change from baseline EMG to 'active' EMG level heard immediately prior to delivery of Botulinum toxin (BTX) from 1-5. Value from 1 = no significant step change heard, to 5 = a very clear step change heard.	Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
Secondary	Clinical Score of Needle Placement Accuracy	Clinician's score of their confidence in accurate needle placement with respect to the target muscle. Given as a percentage, a higher score indicates more confidence in accurate needle placement.	Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
Secondary	Clinical Score of EMG Quality.	Clinician's score of overall quality of the EMG signal heard during the procedure. A higher score indicates better quality of EMG signal, and is quantified as 1 to 5, where: 1 indicates signal not present and 5 indicates excellent quality EMG signal.	Approximately 5 minutes, i.e. immediately prior to needle insertion until Botulinum toxin (BTX) delivery and needle withdrawal
Secondary	Post-treatment Angle of Deviation	Change in participant's angle of deviation following treatment, measured in prism dioptres.	2 weeks