Exploring a rare manifestation of vasculitis that challenges diagnosis and threatens vision
A 75-year-old woman visited multiple hospitals complaining of bilateral eye pain and blurred vision, accompanied by fever and poor appetite. She was initially diagnosed with glaucoma and sinusitis, treated with both laser surgery and antibiotics—yet her symptoms persisted. It wasn't until she reached a major medical center that the true, rare culprit was identified: giant cell arteritis (GCA) manifesting as bilateral optic perineuritis (OPN)1 4 .
This case represents more than just a diagnostic challenge—it highlights a critical medical emergency where delayed recognition can lead to permanent vision loss. Through this article, we'll explore how inflammation of arteries can masquerade as eye disease, why timely diagnosis is crucial, and what this rare case teaches us about the intricate connections between vascular and neural structures in the human body.
Systemic inflammatory vasculitis affecting medium-to-large arteries
Inflammation of the optic nerve sheath while sparing nerve axons
Exceptionally rare manifestation posing diagnostic challenges
Giant cell arteritis (GCA), also known as temporal arteritis, is a systemic inflammatory vasculitis that primarily affects adults over 50 years old3 . It causes inflammation of the lining of arteries, leading to swelling that narrows blood vessels and reduces blood flow to tissues3 .
When GCA affects vision, it typically does so through arteritic anterior ischemic optic neuropathy (AAION), where inflammation blocks the posterior ciliary arteries supplying the optic nerve head1 6 .
Optic perineuritis (OPN) is characterized by inflammation targeting the optic nerve sheath—the protective covering around the optic nerve—while typically sparing the actual nerve axons that transmit visual information1 7 .
This distinction from conventional optic neuritis (which affects the nerve itself) is crucial both mechanistically and clinically.
Unlike the more common AAION caused by GCA, OPN represents inflammation of the pial vessels and vasa nervorum (small vessels supplying the nerve sheath) rather than occlusion of the larger posterior ciliary arteries1 . This different mechanism explains why OPN may present with preserved central vision and potentially better visual outcomes compared to AAION7 .
| Feature | Typical GCA (AAION) | Atypical GCA (OPN) |
|---|---|---|
| Primary target | Posterior ciliary arteries | Optic nerve sheath vessels |
| Optic disc appearance | Edema (swelling) common | Often normal without edema |
| Visual acuity | Often severely impaired | May be relatively preserved |
| Central vision | Frequently affected | Often spared |
| MRI finding | Optic nerve enhancement | Nerve sheath enhancement |
| Visual field defects | Altitudinal or generalized | Variable, often peripheral |
The case report from 2025 detailed a 75-year-old female with a medical history including pulmonary hypertension, dyslipidemia, and heart failure who presented with a 3-week history of bilateral eye pain followed by blurred vision1 4 .
Her symptoms were accompanied by constitutional signs of inflammation: documented fever (38.2°C), headache, and poor appetite1 .
Crucially, the patient had initially been misdiagnosed with glaucoma and sinusitis at multiple hospitals—a common theme in rare disease presentations where early symptoms mimic more common conditions1 . She underwent unnecessary laser eye surgery and received antibiotics without any improvement1 .
The ophthalmological examination revealed important findings that helped steer the diagnosis toward the correct path:
The preservation of color vision and absence of disc edema were particularly noteworthy, as these findings are unusual in the more typical arteritic ischemic optic neuropathies caused by GCA.
The laboratory results provided critical objective evidence supporting the inflammatory nature of her condition:
These findings, especially the dramatically elevated ESR and CRP, raised strong suspicion for a systemic inflammatory process such as vasculitis.
Contrast-enhanced orbital MRI provided the crucial imaging evidence that confirmed the diagnosis of optic perineuritis, demonstrating bilateral optic nerve sheath enhancement that spared the actual optic nerves themselves and extended toward the chiasm and pituitary stalk1 4 .
This characteristic "tram-track" appearance of perineural enhancement on MRI is the radiologic hallmark of OPN and helped distinguish this condition from other optic neuropathies1 .
A right temporal artery biopsy was performed, which revealed the classic histologic features of GCA1 4 :
This biopsy confirmation was essential for definitively establishing the diagnosis of GCA, as it provides the highest specificity for this condition6 .
| Diagnostic Method | Key Findings | Clinical Utility |
|---|---|---|
| Inflammatory markers | Elevated ESR & CRP | Screening, disease activity monitoring |
| Orbital MRI with contrast | Optic nerve sheath enhancement | Differentiates OPN from other optic neuropathies |
| Temporal artery biopsy | Granulomatous inflammation, internal elastic lamina disruption | Gold standard for GCA diagnosis |
| Color vision testing | Often normal in OPN | Differentiates from typical optic neuritis |
| Fundoscopic examination | No disc edema (in pure OPN) | Contrasts with AAION findings |
| Vascular ultrasound | Halo sign (vessel wall edema) | Non-invasive supportive evidence |
Given the potential for rapid, irreversible vision loss in GCA, treatment was initiated empirically with high-dose intravenous corticosteroids on the same day as the temporal artery biopsy, without waiting for histopathological results1 6 .
The patient received intravenous dexamethasone 60 mg three times, followed by transition to oral prednisolone 60 mg daily1 .
This aggressive steroid approach is standard in suspected GCA with visual symptoms, as the risk of permanent vision loss outweighs the potential side effects of short-term high-dose steroid treatment6 .
The patient's management followed current best practices for GCA:
At the two-month follow-up, the patient was completely asymptomatic with stable visual acuity of 20/40 in both eyes—a remarkably positive outcome considering the potential for permanent blindness in untreated GCA1 4 .
Patient presents with bilateral eye pain, blurred vision, fever, and headache. Initial misdiagnosis as glaucoma and sinusitis.
Elevated inflammatory markers (ESR 120 mm/h, CRP 141 mg/L) and MRI showing bilateral optic nerve sheath enhancement lead to correct diagnosis of GCA with OPN.
High-dose IV corticosteroids initiated immediately. Temporal artery biopsy performed.
Marked reduction in headache and eye pain within two days of steroid initiation.
Patient completely asymptomatic with stable visual acuity of 20/40 in both eyes. Tocilizumab added as steroid-sparing agent.
Advances in understanding and diagnosing rare conditions like GCA-associated OPN rely on specialized research reagents and clinical tools:
| Tool/Reagent | Primary Function | Application in GCA/OPN |
|---|---|---|
| Contrast agents (gadolinium) | Enhance visualization of inflammation on MRI | Detect optic nerve sheath enhancement in OPN |
| Histopathology stains (H&E, Elastic Verhoeff) | Visualize tissue architecture and elastic fibers | Identify inflammatory infiltrates and internal elastic lamina disruption in TAB |
| Immunoassays for inflammatory markers | Quantify ESR, CRP, IL-6 levels | Monitor disease activity and treatment response |
| Automated perimetry (Humphrey Visual Field) | Map visual field defects | Document functional visual impairment patterns |
| CD4+ T-cell markers | Identify T-lymphocyte subsets | Research on immunopathogenesis of GCA |
| VEGF assays | Measure angiogenic factor levels | Research on vascular remodeling in vasculitis |
| IL-6 receptor inhibitors (tocilizumab) | Block pro-inflammatory cytokine signaling | Steroid-sparing treatment for GCA maintenance |
This case of bilateral OPN as a GCA manifestation holds several important lessons for clinicians:
Despite advances in understanding, important questions remain:
Developing more targeted biologic treatments with fewer side effects
Validating non-invasive diagnostic protocols to replace temporal artery biopsy
Establishing international registries for rare GCA manifestations
The case of bilateral optic perineuritis as a manifestation of giant cell arteritis represents both a diagnostic challenge and a therapeutic opportunity. Through the systematic evaluation of a 75-year-old woman with unexplained eye pain and visual disturbance, clinicians were able to identify a rare presentation of a serious systemic condition and initiate potentially vision-saving treatment.
This case underscores several fundamental principles in medicine: the importance of considering uncommon manifestations of common diseases, the value of a thorough diagnostic approach when initial treatments fail, and the dramatic benefits that can follow timely intervention in conditions with potentially devastating outcomes.
As research continues to unravel the complexities of giant cell arteritis and its varied presentations, the recognition of optic perineuritis as part of its spectrum ensures that future patients with similar symptoms may benefit from more rapid diagnosis and preservation of their precious visual function.