An observational study in Giant Cell Arteritis, Temporal Arteritis and Optic Nerve Diseases, sponsored by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal. Not yet recruiting at 1 site in Canada. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2026-04-02.
Sponsored by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal · Observational
Giant cell arteritis (GCA) is an inflammatory disease of large and medium arteries that can cause irreversible vision loss. Glucocorticoids (GCs) rapidly suppress inflammation, but diagnostic imaging tests such as temporal artery ultrasound or biopsy often become falsely negative within days of treatment. The optic nerve sheath diameter (ONSD), measurable by ocular ultrasound, reflects perineural edema and may serve as a quantitative biomarker of ocular inflammation in GCA.
The SONIC-TIME study (Early Temporal Dynamics of Optic Nerve Sheath Diameter After Glucocorticoid Therapy in Giant Cell Arteritis) is a single-center, prospective observational substudy embedded within SONIC-GCA (NCT05749094) at Hôpital du Sacré-Cœur de Montréal. It aims to characterize how rapidly ONSD decreases after GC initiation and how this trajectory relates to cumulative GC exposure, intravenous methylprednisolone, and early use of steroid-sparing therapies.
Sixty participants with newly diagnosed GCA will undergo serial optic nerve sheath ultrasound, blood tests (CRP, ESR), and when feasible, temporal artery ultrasound over the first two months of therapy (Days 3, 7, 10, 14, 21, 28, and Month 2). No experimental treatments are given; all participants receive standard-of-care therapy.
The primary objective is to quantify the percent change in mean ONSD from baseline to Day 28. Secondary objectives include modeling ONSD change over time, assessing associations with cumulative steroid dose and inflammatory markers, and estimating the time to normalization below the SONIC-GCA cutoff. Findings will define the optimal imaging window and refine the diagnostic and monitoring role of optic nerve ultrasound in GCA.
170 studies on the registry are indexed under Giant Cell Arteritis; 48 are open to participants now.
This study's planned enrollment of 60 is below the median of 122 across 85 observational studies indexed under Giant Cell Arteritis.
Browse Giant Cell Arteritis studies →Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal is the lead sponsor of 31 studies on the registry; 15 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Eligible patients will consist of those who consult at our GCA fast-track clinic, have completed the SONIC-GCA baseline procedures, and have received a diagnosis of GCA on that visit.
Participants must be enrolled in SONIC-GCA and must have:
Exclusion Criteria:
1) Concurrent participation in a blinded interventional pharmaceutical clinical trial.
Patients with new-onset GCA who completed the SONIC-GCA (main study) baseline visit and who received 48 hours or less of glucocorticoids and less or equal to 160mg of oral prednisone equivalent. Study visits : Baseline, then days 3, 7, 10, 14, 21, 28, and Month 2
Diagnostic Test: Optic Nerve Sheath Ultrasound · Diagnostic Test: Temporal artery ultrasound · Diagnostic Test: Bloodwork : CRP and ESR
Optic nerve sheath ultrasound will be performed in combination with a digital retinal fundoscopy.
With measurement of the intima-media complex and calculation of the OGUS.
At each visit
Change in mean ONSD (in mm) from day 0 to day 28
To quantify the change in mean ONSD (in mm, by ultrasound) between baseline (Day 0) and Day 28 after GC initiation in patients with GCA exposed to ≤ 48 hours and ≤ 120 mg prednisone-equivalent before baseline.
Time frame: Day 28
Change in mean ONSD (in mm, using ultrasound) from day 0 to day 14
To quantify the change in mean ONSD between baseline (Day 0) and Day14 after GC initiation in patients with GCA exposed to ≤ 48 hours and ≤ 120 mg prednisone-equivalent before baseline.
Time frame: Day 14
Change in mean ONSD (in mm, using ultrasound) from day 0 to month 2
To model ONSD change over the first eight weeks using with time-updated cumulative GC exposure.
Time frame: Month 2
Association between cumulative glucocorticoids (GCs, in mg) and ONSD (in mm, by ultrasound)
To determine the dose-response relationship between ONSD and cumulative GC exposure.
Time frame: Month 2
Association between IV methylprednisolone (binary : yes or no) and ONSD (in mm, by ultrasound)
To evaluate the influence of IV methylprednisolone on ONSD evolution.
Time frame: Month 2
Association between immunosuppressive therapy (categorical, documented using medication list) and ONSD (in mm, by ultrasound)
To assess the impact of early initiated steroid-sparing therapies initiated as standard of care on ONSD trajectory.
Time frame: Month 2
ONSD threshold (from the SONIC-GCA trial) performance over time
To evaluate the time-adjusted ONSD performance based on the established SONIC-GCA ONSD cutoff.
Time frame: Month 2
Time (in days) to ONSD normalization
To estimate the adjusted time to first attainment of an ONSD value below the established SONIC-GCA ONSD cutoff.
Time frame: Month 2
Association between inflammatory markers and ONSD
To quantify correlations between ONSD and systemic inflammatory biomarkers over the early therapy period.
Time frame: Month 2
Association between OGUS and ONSD
To examine associations between ONSD and the temporal artery ultrasound OGUS score over the early therapy period.
Time frame: Month 2
Association between digital retinal fundoscopy and ONSD (in mm, by ultrasound)
To compare ONSD trajectories between participants with and without GCA-related retinal abnormalities on digital retinal fundoscopy.
Time frame: Month 2
Plan to share: Undecided
This study is not yet recruiting, as verified in Oct 2025. You cannot join it, but the record below documents what was studied.
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Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal