Early Temporal Dynamics of Optic Nerve Sheath Diameter After Therapy in GCA (SONIC-TIME)

Early Temporal Dynamics of Optic Nerve Sheath Diameter After Glucocorticoid Therapy in Giant Cell Arteritis

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Optic Nerve Diseases; Giant Cell Arteritis; Diagnosis; Temporal Arteritis
• Intervention / Treatment: Diagnostic test: Optic Nerve Sheath Ultrasound; Diagnostic test: Temporal artery ultrasound; Diagnostic test: Bloodwork : CRP and ESR

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Jean-Paul Makhzoum, MD, MSc; Phone Number: 514-338-2222; Email: jean-paul.makhzoum@umontreal.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H4J1C5
      • Vasculitis Clinic, Hopital du Sacre-Coeur de Montreal

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

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.

Description

Inclusion Criteria:

1. Participants must be enrolled in SONIC-GCA and must have:

   • completed the baseline optic nerve sheath ultrasound
   • confirmed GCA as determined by the baseline standardized GCA assessment in SONIC-GCA.
2. Exposure to glucocorticoids for ≤ 48 hours and ≤ 160 mg prednisone-equivalent before baseline.
3. Ability and willingness to provide written informed consent.
4. Agreement to complete the SONIC-TIME intensive follow-up schedule.

Exclusion Criteria:

1) Concurrent participation in a blinded interventional pharmaceutical clinical trial.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
GCA group; 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; Optic nerve sheath ultrasound will be performed in combination with a digital retinal fundoscopy.; Diagnostic test: Temporal artery ultrasound; With measurement of the intima-media complex and calculation of the OGUS.; Diagnostic test: Bloodwork : CRP and ESR; At each visit

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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.	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.	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.	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.	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.	Month 2
Association between inflammatory markers and ONSD	To quantify correlations between ONSD and systemic inflammatory biomarkers over the early therapy period.	Month 2
Association between OGUS and ONSD	To examine associations between ONSD and the temporal artery ultrasound OGUS score over the early therapy period.	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.	Month 2

Collaborators and Investigators

• Sponsor: Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
• Investigators: Study Chair: Jean-Paul Makhzoum, MD, MSc, CISSS du Nord-de-l'ile de Montreal

Publications and helpful links

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): May 1, 2028

Study Registration Dates

• First Submitted: March 23, 2026
• First Submitted That Met QC Criteria: March 31, 2026
• First Posted (Actual): April 2, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Autoimmune Diseases; Immune System Diseases; Eye Diseases; Autoimmune Diseases of the Nervous System; Skin Diseases; Skin Diseases, Vascular; Cranial Nerve Diseases; Vasculitis; Vasculitis, Central Nervous System; Arteritis; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Disease; Giant Cell Arteritis; Optic Nerve Diseases; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Hematologic Tests; Blood Sedimentation
• Other Study ID Numbers: 2026-3095

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No