COmparison of Clarus and Optos Ultrawide Field Imaging Systems for Geographic Atrophy (COCO-GA)

COmparison of Clarus and Optos Ultrawide Field Imaging Systems for Geographic Atrophy (COCO-GA) Protocol

The goal of this clinical trial is to compare measurements of geographic atrophy (GA) area between several types of imaging, in order to assess accuracy. The main question to answer is which imaging device provides measurements that are most similar to the standard of care device.

Participants will be patients of a retina doctor at University Station Eye Clinic with geographic atrophy, and can expect to be in the study for 60-75 minutes.

Study Overview

• Status: Completed
• Conditions: Geographic Atrophy; Macular Degeneration, Age Related
• Intervention / Treatment: Device: Spectralis FAF imaging; Device: Optos imaging; Device: Zeiss Clarus 700 imaging

Detailed Description

This study is a single site pilot comparative imaging study in which enrolled participants will undergo dilated fundus exam as per standard of care. Study images will be obtained using Optos ultrawide field fundus autofluorescence (FAF) and both blue and green ultrawide field FAF with Zeiss Clarus. Autofluorescence (AF) imaging will also be performed on the Spectralis as it is currently the gold standard. The goal will be to obtain all images in 60-75 minutes over one visit. Images will be assessed, and area of geographic atrophy measured independently by two experienced readers.

• Study Type: Interventional
• Enrollment (Actual): 62
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53705
      • University of Wisconsin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 50 years or older and may be either male or female and may be of any race
• Established diagnosis of GA due to AMD
• GA characteristics: GA area of between 1.25 mm² and 23 mm², with seventy percent of eyes having GA area ranging from 2.5 mm² to 17.5 mm². GA may be unifocal or multifocal. GA may be subfoveal or extrafoveal, with twenty-five percent of eyes having subfoveal GA. The presence of concurrent peripapillary atrophy will not exclude subjects from participation
• Willing to participate as evidenced by signing the written informed consent

Exclusion Criteria:

• Unable to tolerate opthalmic imaging
• Presence of neovascular AMD on OCT as confirmed by an ophthalmologist
• Presence of significant media opacity preventing adequate retinal imaging
• Presence of concurrent retinal disease which may confound assessment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Fundus autofluorescence (FAF) imaging

Device: Spectralis FAF imaging; Spectralis is a scanning laser ophthalmoscope which uses a blue light excitation wavelength of 488nm and a 500nm barrier filter to produce FAF images. Spectralis images 20-55 degrees of the retina.; Device: Optos imaging; Optos is an ultrawide field imaging platform which images up to 200 degrees of the retina. It uses both a green-light excitation wavelength of 532nm and a red-light excitation wavelength of 633nm with an emission filter of greater than 540nm to produce FAF images.; Device: Zeiss Clarus 700 imaging; Zeiss Clarus 700 is an ultrawide field imaging system with similar retinal coverage to that of Optos. It uses Broad Line Fundus Imaging to produce blue FAF images at excitation wavelengths of 435-500nm and green FAF images at wavelengths of 500-585nm

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of Geographic Atrophy Area Measurements With Heidelberg Spectralis to Zeiss Clarus 700 and Optos California	Graders will independently measure area of GA from images of each device. The measurements (in mm²) will be compared between the devices.	Up to 75 minutes
Comparison of Geographic Atrophy Area Measurements With Heidelberg Spectralis to Zeiss Clarus 700 and Optos California (Full Range Reported)	Graders will independently measure area of GA from images of each device. The measurements (in mm²) will be compared between the devices.	Up to 75 minutes
Number of Eyes With Greater Than 10% Difference in Geographic Atrophy Area Than Heidelberg RegionFinder		up to 75 mintues

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prevalence of Atrophy Outside the Standard 30 Degrees in Clarus and Optos Ultrawide Field Images	The presence of atrophy outside field 2 will be documented from the two ultrawide field imaging devices	Up to 75 minutes
Prevalence of Other Autofluorescence Abnormalities Outside the Standard 30 Degrees in Clarus and Optos Ultrawide Field Images	The presence of abnormal autofluorescence outside field 2 will be documented from the two ultrawide field imaging devices	Up to 75 minutes

Other Outcome Measures

Outcome Measure	Time Frame
Geographic Atrophy Characteristics at Baseline Visit for Each Imaging Modality	up to 75 minutes
Geographic Atrophy Characteristics at Baseline Visit for Each Imaging Modality: Junctional Zone Pattern	up to 75 minutes

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Investigators: Principal Investigator: Amitha Domalpally, MD, PhD, University of Wisconsin, Madison

Study record dates

Study Major Dates

• Study Start (Actual): October 6, 2023
• Primary Completion (Actual): May 27, 2025
• Study Completion (Actual): May 27, 2025

Study Registration Dates

• First Submitted: July 18, 2023
• First Submitted That Met QC Criteria: July 18, 2023
• First Posted (Actual): July 27, 2023

Study Record Updates

• Last Update Posted (Actual): June 15, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Retinal Diseases; Retinal Degeneration; Macular Degeneration; Geographic Atrophy
• Other Study ID Numbers: 2023-0958; SMPH/OPHTHAL&VIS SCI/FPRC (Other Identifier: UW Madison); Protocol Version 3/20/2025 (Other Identifier: UW Madison)

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: Yes
• product manufactured in and exported from the U.S.: No