Electroretinography: Investigation of a Protocol Change (SHERG)

Investigation of a Protocol Change (Shorter Dark-adaptation) on the Electroretinogram (ERG) in an Adult Patient Population (SHERG)

The study evaluates whether an eye test called an electroretinogram (ERG) can be shortened and still produce the same diagnostic results. The results of this study may allow test times to be reduced which will have benefits such as improved patient compliance during shorter testing and increased clinic efficiency.

Study Overview

• Status: Unknown
• Conditions: Dark-adapted ERG
• Intervention / Treatment: Diagnostic test: Electroretinography

Detailed Description

A full-field electroretinogram (ERG) is a standardised eye test undertaken in specialist hospital clinics. ERGs are useful for diagnosing and monitoring retinal diseases. The retina is stimulated by showing patients flashes of light and the resulting electrical response from the eye is recorded using delicate electrodes that touch the surface of the eye. For the first section of the test, patient's eyes are allowed to adjust to the dark to ensure the parts of the retina responsible for seeing in dimly-lit conditions are being tested.

The international ERG Standard says patients must sit in the dark for 20 minutes. The investigators have evidence to suggest the test may be equally useful after only 10 minutes in the dark. The investigators plan to compare ERGs recorded from patients who have spent only 10 minutes in the dark with ERGs recorded from the same patients after the full 20 minutes in the dark. If the difference is suitably small, as found in a preliminary study of healthy individuals, it could be justifiable to shorten the routine patient protocol.

Subjects for this study will be recruited from the adult population routinely attending for an outpatient ERG test. During their routine ERG test, 10 minutes into the 20 minute wait in the dark, the investigators propose recording an additional, identical set of ERG tests. This will not add extra time to the clinical test.

Participants will not need any follow-up for the research study. The study requires 262 patients to test the hypothesis, and the investigators estimate this will take about 5-6 months.

• Study Type: Observational
• Enrollment (Anticipated): 262

Contacts and Locations

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patient population attending hospital for routine clinical electroretinography.

Description

Inclusion Criteria:

• Patients referred to the adult visual electrophysiology service regardless of clinical condition, and who require dark-adapted electroretinography as part of their appointment
• Male or female
• All ethnicities

Exclusion Criteria:

• Patients less than 18 years old
• Patients who might have difficulties understanding the participant information provided (for example, those patients requiring a translator, or who have learning difficulties)
• Patients with photosensitive epilepsy
• Patients appointed for clinical testing urgently, or via telephone, who will not have had an opportunity to receive and review the participant information sheet ahead of the clinical appointment.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adult patients; Adult patients attending hospital for clinical visual electrophysiology.	Diagnostic test: Electroretinography; An additional electroretinogram performed after 10 minutes of dark adaptation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of classification for ERG following 10 minute dark adaptation	The rate of classification (normal vs abnormal) for testing conducted after 10 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 10 minutes of dark adaptation
Rate of classification (normal vs abnormal) for ERG following 20 minute dark adaptation	The rate of classification (normal vs abnormal) for testing conducted after 20 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 20 minutes of dark adaptation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Response amplitude after 10 minutes	Measurement of the amplitude of responses following 10 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 10 minutes of dark adaptation
Response amplitude after 20 minutes	Measurement of the amplitude of responses following 20 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 20 minutes of dark adaptation
Response timing	Measurement of the amplitude of responses following 10 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 10 minutes of dark adaptation
Response timing	Measurement of the amplitude of responses following 20 minutes of dark adaptation.	(During first & only study visit) Dark-adapted ERG test following 20 minutes of dark adaptation
Response variability	Measurement of the variability of responses following 10 minutes of dark	(During first & only study visit) Dark-adapted ERG test following 10 minutes of dark adaptation
Response variability	Measurement of the variability of responses following 20 minutes of dark	(During first & only study visit) Dark-adapted ERG test following 20 minutes of dark adaptation

Collaborators and Investigators

• Sponsor: NHS Greater Glasgow and Clyde
• Investigators: Study Director: Ruth Hamilton, PhD, NHS Greater Glasgow & Clyde; Principal Investigator: Kirsten Graham, MSc, NHS Greater Glasgow & Clyde; Principal Investigator: Richard Hagan, PhD, NHS Royal Liverpool University Hospital

Study record dates

Study Major Dates

• Study Start (ANTICIPATED): October 1, 2017
• Primary Completion (ANTICIPATED): February 1, 2018
• Study Completion (ANTICIPATED): February 1, 2018

Study Registration Dates

• First Submitted: March 22, 2017
• First Submitted That Met QC Criteria: September 5, 2017
• First Posted (ACTUAL): September 7, 2017

Study Record Updates

• Last Update Posted (ACTUAL): September 7, 2017
• Last Update Submitted That Met QC Criteria: September 5, 2017
• Last Verified: September 1, 2017

More Information

Terms related to this study

• Keywords: electrophysiology; electroretinogram; ophthalmology; electroretinography; ERG; dark-adaptation; ISCEV; scotopic
• Other Study ID Numbers: GN17OP146

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No