Longitudinal Prospective Natural History Study of Retinopathy in Zellweger Spectrum Disorder
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Zellweger Spectrum Disorder. Basic parameters: No limits · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States, Canada
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Overview
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.
Detailed description
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.
Primary outcome measures
- Number of participants with disease progression [Time frame: 5 years]
- Number of participants with common patterns of retinal degeneration observed [Time frame: 5 years]
Secondary outcome measures (3)
- Rate of progression of retinal degeneration [Time frame: 5 years]
- Correlation of rate retinal degeneration to age and overall ZSD disease severity [Time frame: 5 years]
- rate of progression of retinal degeneration [Time frame: 5 years]
Eligibility criteria
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Canada · 2 centers
- Eye Institute of Alberta — Edmonton
- Research Institute-McGill University Health Center — Montreal
United States · 1 center
- University of Rochester Medical Center/Flaum Eye Institute — Rochester
Publications
- Braverman NE, Raymond GV, Rizzo WB, Moser AB, Wilkinson ME, Stone EM, Steinberg SJ, Wangler MF, Rush ET, Hacia JG, Bose M. Peroxisome biogenesis disorders in the Zellweger spectrum: An overview of current diagnosis, clinical manifestations, and treatment guidelines. Mol Genet Metab. 2016 Mar;117(3):313-21. doi: 10.1016/j.ymgme.2015.12.009. Epub 2015 Dec 23. PMID 26750748
- Yergeau C, Coussa RG, Antaki F, Argyriou C, Koenekoop RK, Braverman NE. Zellweger Spectrum Disorder: Ophthalmic Findings from a New Natural History Study Cohort and Scoping Literature Review. Ophthalmology. 2023 Dec;130(12):1313-1326. doi: 10.1016/j.ophtha.2023.07.026. Epub 2023 Aug 2. PMID 37541626
Identifiers
NCT: NCT06190626 · 2024-9679