Is a feeling of something being in the eye a symptom of optic neuritis, Multiple Sclerosis (MS)-associated optic neuritis, Neuromyelitis Optica Spectrum Disorder (NMOSD), Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD), or Systemic Lupus Erythematosus (SLE)?

Foreign Body Sensation Is Not a Typical Symptom of Optic Neuritis

A feeling of something in the eye (foreign body sensation) is not a characteristic symptom of optic neuritis in any of these conditions—MS, NMOSD, MOGAD, or SLE. The hallmark symptoms of optic neuritis are periocular pain worsening with eye movement, subacute visual loss, color desaturation, and photophobia 1.

Typical Optic Neuritis Symptoms Across All Conditions

The classic presentation of optic neuritis includes:

• Periocular pain that worsens with eye movement is the most characteristic symptom, occurring in the majority of cases across MS, NMOSD, MOGAD, and SLE-related optic neuritis 1
• Subacute visual impairment developing over hours to days (not instantaneous) is a defining feature 1, 2
• Red-green color desaturation (dyschromatopsia) is characteristic and helps distinguish optic neuritis from other causes of vision loss 1
• Photophobia is commonly reported as an associated symptom 1
• Visual field defects, particularly central scotomas, are typical findings 1

Why Foreign Body Sensation Is Not Part of the Clinical Picture

Foreign body sensation suggests:

• Corneal or conjunctival pathology rather than optic nerve inflammation, which occurs posterior to the globe
• Surface eye problems such as dry eye, conjunctivitis, or corneal abrasion—none of which are features of optic neuritis
• The optic nerve inflammation in optic neuritis occurs along the nerve itself (intraorbital, canalicular, intracranial segments), not at the ocular surface where foreign body sensation would originate 3

Distinguishing Features Among Different Conditions

While foreign body sensation is not a symptom of any form of optic neuritis, these conditions do have distinguishing characteristics:

NMOSD-Related Optic Neuritis

• Severe visual deficit or blindness is more common than in MS-related optic neuritis 1
• Bilateral simultaneous involvement is a red flag for NMOSD rather than MS 1
• Prominent papilledema or optic disc swelling during acute episodes 1
• Long optic nerve lesions extending >50% of nerve length or involving the optic chiasm 1

MOGAD-Related Optic Neuritis

• Optic disc swelling is frequently observed (11/28 patients in one series) 3
• Longitudinal extensive optic nerve lesions involving ≥4 of 5 segments 3
• Bilateral optic neuritis and steroid-dependent relapses are more common 1

MS-Related Optic Neuritis

• Typically unilateral presentation 1
• Shorter optic nerve lesions (median 9.9-10.5 mm) compared to MOGAD 3
• Nodular, open-ring, or closed-ring enhancement patterns on MRI (not cloud-like) 1

SLE-Related Optic Neuritis

• Poor visual outcomes, with only 30% maintaining visual acuity >20/25 1, 4
• May present bilaterally 1
• Treatment delay beyond 2 weeks is particularly unfavorable 1

Critical Clinical Pitfall

If a patient presents with a foreign body sensation and visual symptoms, consider alternative diagnoses such as:

• Anterior segment pathology (corneal abrasion, keratitis, conjunctivitis)
• Uveitis or scleritis (which can cause both foreign body sensation and vision changes)
• Concurrent but unrelated ocular surface disease in a patient who happens to have optic neuritis

The absence of periocular pain with eye movement and the presence of foreign body sensation should prompt reconsideration of the diagnosis of optic neuritis 1, 2.