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Completed

NCT Number: NCT05961332

COmparison of Clarus and Optos Ultrawide Field Imaging Systems for Geographic Atrophy

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.

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Key information

Conditions

Macular Degeneration, Age Related Eye Diseases Geographic Atrophy Macular Degeneration Retinal Degeneration Retinal Diseases

Age range

50 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Wisconsin

Madison, Wisconsin, 53705, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Spectralis FAF imaging

Device

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.

Optos imaging

Device

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.

Zeiss Clarus 700 imaging

Device

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

Primary outcomes

  1. Comparison of Geographic Atrophy Area Measurements With Heidelberg Spectralis to Zeiss Clarus 700 and Optos California

    Time frame: Up to 75 minutes

    Graders will independently measure area of GA from images of each device. The measurements (in mm²) will be compared between the devices.

  2. Comparison of Geographic Atrophy Area Measurements With Heidelberg Spectralis to Zeiss Clarus 700 and Optos California (Full Range Reported)

    Time frame: Up to 75 minutes

    Graders will independently measure area of GA from images of each device. The measurements (in mm²) will be compared between the devices.

  3. Number of Eyes With Greater Than 10% Difference in Geographic Atrophy Area Than Heidelberg RegionFinder

    Time frame: up to 75 mintues

Secondary outcomes

  1. Prevalence of Atrophy Outside the Standard 30 Degrees in Clarus and Optos Ultrawide Field Images

    Time frame: Up to 75 minutes

    The presence of atrophy outside field 2 will be documented from the two ultrawide field imaging devices

  2. Prevalence of Other Autofluorescence Abnormalities Outside the Standard 30 Degrees in Clarus and Optos Ultrawide Field Images

    Time frame: Up to 75 minutes

    The presence of abnormal autofluorescence outside field 2 will be documented from the two ultrawide field imaging devices

Other outcomes

  1. Geographic Atrophy Characteristics at Baseline Visit for Each Imaging Modality

    Time frame: up to 75 minutes

  2. Geographic Atrophy Characteristics at Baseline Visit for Each Imaging Modality: Junctional Zone Pattern

    Time frame: up to 75 minutes

Sponsors and collaborators

Lead sponsor

University of Wisconsin, Madison

Other

Registry information

Official study title

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

Acronym: COCO-GA

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Jul 27, 2023
Registry last updated
Jul 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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