Optic neuritis is an inflammatory disorder affecting the optic nerve anywhere along its path, characterized by the abrupt onset of vision loss, and sometimes ocular pain, which may be intensified by eye movement.1,2
Optic neuritis primarily affects young adults, with a notable predilection for women, and is often linked to autoimmune pathologies such as multiple sclerosis (MS).1,2
The annual incidence is estimated between 1.2 and 5.0 per 100,000 individuals, with increased prevalence among those of Northern European descent or residents of regions with limited sunlight exposure, possibly due to vitamin D deficiency.3
The age range most susceptible is 18 to 45 years, and the female-to-male ratio is approximately 3:1.3 Optic neuritis can manifest independently or concurrently in up to 20% of patients with MS.3,4
Categorization and classification of optic neuritis
Optic neuritis is categorized based on its clinical presentation and underlying cause. Traditionally, cases are divided into typical and atypical optic neuritis, with most typical cases being associated with MS.5
Ophthalmoscopic classifications include:2
- Retrobulbar optic neuritis: Characterized by inflammation posterior to the globe without observable changes upon examination
- Papillitis: Identified by inflammation of the optic disc
- Neuroretinitis: A less common variant involving both the optic nerve and retina, frequently associated with systemic infections such as Lyme disease
Etiologically, optic neuritis can be attributed to autoimmune or inflammatory processes, often correlated with MS or neuromyelitis optica spectrum disorder (NMOSD); infectious agents, including viral, bacterial, or parasitic pathogens; or toxic/drug-induced factors, such as ethambutol, chloroquine, or alcohol.2
Ischemic optic neuritis, arising from compromised blood supply to the optic nerve, is more frequently observed in individuals above 50 or those with vascular risk factors.1,2
Optic neuritis may also present as a secondary manifestation of malignancy, systemic disorders like lupus, or physical trauma to the optic nerve.1,2 Although visual impairment is the primary clinical feature, the diverse underlying etiologies necessitate tailored diagnostic and therapeutic approaches.
Download the cheat sheet here!
Atypical Optic Neuritis Differential Diagnosis Cheat Sheet
This cheat sheet oulines differences in etiologies of atypical optic neuritis, with key signs and symptoms and pearls for testing, management, and referrals.
Atypical optic neuritis: A case report
The case represents a unique presentation of optic neuritis in a pediatric patient, highlighting atypical characteristics that are not prevalent in published literature.
Case history
A 10-year-old Caucasian female presented for an emergency evaluation of blurred vision and eye pain in the right eye only that began 10 days prior. The patient denied any recent illness. Recent vaccinations included influenza and a tetanus booster. This was her first eye exam at the clinic.
Key notes from the exam included:
- Medical history was remarkable for seizures as an infant, however not currently under the care of a specialist
- No systemic medications
- No drug-related allergies
- Ocular history was unremarkable
- No significant family ocular or medical history
Uncorrected distance visual acuity was 20/50 PHNI OD, 20/20 OS, 20/20 OU, and 20/20 near acuity OU. Pupils were equal, round, reactive to light, with a 1+ afferent pupillary defect OD in the right eye. Confrontation visual fields revealed inferior temporal constriction OD, and were full to finger count OS.
Extraocular motilities and versions were full OU, with reported pain on eye movement OD. Cover test revealed orthophoria at distance and near. The patient was fully alert to time, place, and person, with a pleasant and sociable mood and recent and remote memory fully intact.
Anterior segment exam was unremarkable. Intraocular pressures were 15mmHg OU by Goldmann applanation tonometry.
Clinical imaging
Dilated fundus examination findings are summarized below, and shown in fundus photographs (Figure 1):
- Optic nerve:
- OD: Blurred margins and associated disc hemorrhages; 0.1 V/H cup to disc
- OS: Flat and pink with distinct margins and healthy neural retinal rim; 0.2 V/H cup to disc
- Macula: Flat and even with uniform pigment OU
- Vitreous: Clear and attached OU
- Retina: Flat with no holes, tears, breaks, or lesions OU
- Blood vessels: Healthy 2:3 artery-to-vein ratio OU
Figure 1: Fundus photography OU, highlighting documented disc edema with associated disc hemorrhages OD.
Figure 1: Courtesy of Inrava Khasnabish OD, FAAO.
Figures 2 and 3: As fixation was difficult for the patient, optical coherence tomography (OCT) of the macula was obtained with a partial view of the optic nerve and revealed disc edema OD only (Figure 2).
Figure 2: Courtesy of Inrava Khasnabish OD, FAAO.
Figure 2: Courtesy of Inrava Khasnabish OD, FAAO3
Figures 4 and 5: 24-2 Octopus visual field OD and OS, respectively, which revealed an inferior altitudinal defect.
Figure 4: Courtesy of Inrava Khasnabish OD, FAAO.
Figure 5: Courtesy of Inrava Khasnabish OD, FAAO.
Management
The patient was referred to the nearest emergency room for immediate evaluation by pediatric neurology, including magnetic resonance imaging (MRI) of the brain and orbits with and without contrast.
In retrospect, color vision was not evaluated at the initial emergency evaluation of the patient in this case and would have been valuable adjuvant data correlating with the clinical diagnosis.
Differential diagnoses
- Neuromyelitis optica spectrum disorder
- Myelin oligodendrocyte glycoprotein antibody disease (MOGAD)
- Infectious optic neuritis
- Atypical optic neuritis
Full discussion and case can be found in Chapter 20 of Complex Cases in Clinical Ophthalmology.
Case report clinical pearls
- A thorough case history, including vaccination history, is critical for atypical presentations of optic neuritis.
- Entrance testing is important—pupils, confrontation fields, and extraocular motility can provide critical information to anticipate a neurologic diagnosis and the need for further testing.
- Securing ancillary testing can present a significant obstacle in the pediatric or otherwise uncooperative patient, introducing added complexity during real-time management. Reliance on automated testing and imaging devices to confirm the diagnosis can prove difficult.
- Cultivating an open and direct referral network with a local ophthalmology department at a nearby hospital facilitates smooth transitions for patient care and coordination of care.
- When referring patients directly to the emergency or ophthalmology department, providing a personal cell phone or other mode of contacting the referring doctor directly can ensure your patient gets what they need without communication gaps.
- Referring doctors can order basic imaging for patients being referred to the emergency room in order to expedite the patient’s care.
For more imaging and clinical pearls on the differential diagnoses, check out the cheat sheet!
Advice to aspiring authors from Inrava Khasnabish OD, FAAO
For those aspiring to write a book, I offer the following advice:
- Maintain detailed records of noteworthy or unique cases you encounter: This is especially when there are distinctive presentations or management approaches, and ensure to retain copies of pertinent ancillary testing.
- This practice provides comprehensive information for publications like posters, presentations, or book chapters.
- Cultivate confidence in your clinical acumen and capabilities: If you possess a substantial collection of work that you wish to share, consider starting with smaller platforms such as state or local associations and conferences as well as writing for eyecare blogs, magazines, and even your state association newsletter and gradually progress to national level conferences (AAO, AOA, etc.) and larger scale projects.
- Procure a publisher: If you are genuinely motivated to author a manuscript, reaching out to publishers is recommended. Reach out to multiple and do not be afraid to be rejected.
- Collaborate with like-minded colleagues: This can be invaluable, as undertaking such a project single-handedly can be arduous.
- Remain flexible: It's also crucial to acknowledge that the anticipated timeline is seldom accurate, given the numerous obstacles, revisions, and formatting adjustments in the publishing process.
- Nevertheless, the fulfillment derived from the completed work makes the endeavor worthwhile and provides an inconceivable sense of satisfaction outside of patient care.
In conclusion
When contributing material to Complex Cases in Clinical Ophthalmology, I knew I wanted to include notable and unique cases encountered throughout my professional experience.
One of the disease states I knew I wanted to illuminate was atypical optic neuritis, as it challenges clinicians to adapt diagnostic strategies, especially when standard testing is limited.
This case underscores the importance of maintaining a broad differential and a high index of suspicion when evaluating optic neuritis, particularly in pediatric patients with atypical features.
Careful attention to history, entrance testing, and funduscopic findings—paired with an understanding of less common etiologies such as NMOSD, MOGAD, and infectious causes—can significantly impact outcomes.
