Orbital Magnetic Resonance Imaging of Ocular Giant Cell Arteritis: A Systematic Review and Individual Participant Data Meta-Analysis

ObjectivesWe conducted a systematic review and individual participant data meta-analysis of publications reporting the ophthalmologic presentation, clinical exam, and orbital MRI findings in ocular giant cell arteritis. MethodsPubMed and Cochrane databases were searched up to January 16, 2022. Publications reporting patient-level data on patients with ophthalmologic symptoms, imaged with orbital MRI and diagnosed with biopsy-proven giant cell arteritis were included. Demographics, clinical symptoms, exam, lab, imaging, and outcomes data were extracted. Methodological quality and completeness of reporting of case reports were assessed. ResultsThirty-two studies were included comprising 51 patients (females=24; median age, 76 years). Vision loss (78%) and headache (45%) were commonly reported visual and cranial symptoms. Ophthalmologic presentation was unilateral (41%) or bilateral (59%). Fundus examination most commonly showed disc edema (64%) and pallor (49%). Average visual acuity was very poor (2.28 logMAR {+/-} 2.18). Diagnoses included anterior (61%) and posterior (16%) ischemic optic neuropathy, central retinal artery occlusion (8%) and orbital infarction syndrome (2%). On MRI, enhancement of the optic nerve sheath (53%), intraconal fat (25%), and optic nerve/chiasm (14%) was most prevalent. Among patients with monocular visual symptoms, 38% showed pathologic enhancement in the asymptomatic eye. Six of seven cases reported imaging resolution after treatment on follow-up MRIs. ConclusionsVision loss, pallid disc edema, and optic nerve sheath enhancement are the most common clinical, fundoscopic and imaging findings reported in patients diagnosed with ocular giant cell arteritis, respectively. MRI may detect subclinical inflammation in the asymptomatic eye and may be an adjunct diagnostic tool. Key PointsO_LIAmong 32 publications comprising 51 patients with biopsy-proven giant cell arteritis, vision loss, pallid disc edema, and optic nerve sheath enhancement were the most commonly reported clinical, fundoscopic and orbital MRI findings, respectively. C_LIO_LIOrbital MRI detected subclinical inflammation in the asymptomatic orbit in 38% of giant cell arteritis patients presenting with monocular visual symptoms. C_LIO_LIMRI may have a diagnostic role in patients with suspected giant cell arteritis and presenting with acute visual symptoms. C_LI