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NCT Number: NCT06190626

Longitudinal Prospective Natural History Study of Retinopathy in Zellweger Spectrum Disorder

The goal of this observational study is to define the course of the retinal degeneration in a ZSD patient cohort.

The objective of this study is to gather information so the investigators can:

1. define the course of the retinal degeneration in a ZSD patient cohort with retinal degeneration 2. define what tests best monitor the progression of the retinal degeneration 3. generate prognostic information about vision loss in ZSD.

At each yearly visit, the participants will answer a functional vision questionnaire, have a physical evaluation, blood test, and participate in a variety of vision tests. The investigators will also collect pertinent medical history.

Participants will travel to study site. The study will provide financial support for board and travel.

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Key information

Conditions

Zellweger Spectrum Disorder Abnormalities, Multiple Brain Diseases Brain Diseases, Metabolic Brain Diseases, Metabolic, Inborn Central Nervous System Diseases Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Digestive System Diseases Eye Diseases Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Genetic Diseases, Inborn Kidney Diseases Liver Diseases Male Urogenital Diseases Metabolic Diseases Metabolism, Inborn Errors Nervous System Diseases Nutritional and Metabolic Diseases Peroxisomal Disorders Retinal Diseases Urogenital Diseases Urologic Diseases Zellweger Syndrome

Sex eligibility

All sexes

Study type

Observational

Primary location

Eye Institute of Alberta, Edmonton, Alberta, Canada

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About this study

Participants/guardians will have a 1-hour virtual interview before the first visit to review the tests and determine which tests the participant is able to perform.

Below is a list of the vision tests used for this study:

Prior to each visit, the participant will complete the PedEyeQ or VFQ-25 questionnaire about functional vision.

At each clinic visit :

  • Refraction and glasses test: this is a general vision test, as commonly conducted by an optometrist, before and after pupil dilation
  • Best corrected visual acuity: the participant's vision will be tested using cards or a chart.
  • Contrast sensitivity: the participant's ability to detect contrast will be tested using a chart.
  • Visual field: the participant's field of vision will be tested by asking them to indicate when they see a stimulus.
  • Reading test: the participant's ability to see written text will be tested using the International Reading Speed Test
  • Color vision test: the participant's ability to see color will be tested using cards
  • Eye exam: the participant's eyes will be examined with a lamp
  • Pupil dilation: to allow the completion of some tests, the participant's pupils will be dilated using medicated eye drops
  • Microperimetry: the participant's macula (central retina) will be visualized.
  • Fundus photography: the participant's fundus (central retina) will be photographed in light and dark conditions
  • Full field stimulus threshold test: the participant's ability to perceive light in different parts of their visual field will be tested
  • Optical coherence tomography (OCT): detailed images of the participant's retina will be taken
  • Fundus autofluorescence: the participant's retinal health will be assessed by imaging the natural fluorescent properties of their retinal pigment epithelium
  • Chromatic pupillometry: the function of different cells in the participant's retina will be determined by measuring their response to light
  • Multi-luminance mobility test (MLMT): the participant will walk through an obstacle course at varying light levels to test their functional vision in different light conditions.
  • Blood collection: a blood sample will be collected and banked to measure peroxisome functions.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • confirmed ZSD with deleterious variants in PEX genes identified
  • confirmed or expected retinal involvement

Exclusion criteria

  • unable to perform a minimum of one vision test
  • severe ZSD disease

Treatment and study plan

Primary outcomes

  1. Number of participants with disease progression

    Time frame: 5 years

    Using various tests of vision measured annually, a description of disease progression will be defined in each participant.

  2. Number of participants with common patterns of retinal degeneration observed

    Time frame: 5 years

    Vision test results from participants will be reviewed together to describe common patterns of retinal degeneration observed.

Secondary outcomes

  1. Rate of progression of retinal degeneration

    Time frame: 5 years

    Statistical analysis using the data from Outcome 1, will be used to generate rate of progression per year over 5 years in each individual.

  2. Correlation of rate retinal degeneration to age and overall ZSD disease severity

    Time frame: 5 years

    Statistical analysis using the data from Outcome 1, will be used to correlate rate of progression per year over 5 years to age and overall ZSD disease severity in each individual.

  3. rate of progression of retinal degeneration

    Time frame: 5 years

    Statistical analysis using the data from Outcome 1, will be used to define variance between participants in rate of progression of retinal degeneration.

Study contacts

Contact information is provided by the study sponsor or research team.

Frederique Arnaud, BScN

CONTACT

[email protected]

514-934-1934 ext. 23404

Nancy E Braverman, MD, MS

CONTACT

[email protected]

514-934-1934 ext. 23404

Sponsors and collaborators

Lead sponsor

McGill University Health Centre/Research Institute of the McGill University Health Centre

Other

Collaborators

  • Canadian Institutes of Health Research (CIHR)

Registry information

Acronym: ZSDvision

Important dates

Study start
2023
Primary completion
2029
Study completion
2029
First posted
Jan 5, 2024
Registry last updated
Jan 21, 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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