Neuro-ophthalmologists commonly encounter high rates of diagnostic error in the cases referred to them, which could lead to unnecessary or even inappropriate tests and treatments. To assess the impact, researchers decided to evaluate the extent to which patients were misdiagnosed prior to the neuro-ophthalmology referral and whether they suffered harm as a result. The findings offer a sobering look at the gap between generalist and specialist care in neuro-ophthalmic cases.

In this prospective cross-sectional study, researchers collected data from 496 patients regarding demographics, prior care, referral diagnosis, final diagnosis, diagnostic testing, treatment, patient disposition and impact of the neuro encounter.

Referral diagnosis was incorrect in almost half the cases—49%, which is consistent with prior studies’ results. Furthermore, 26% of misdiagnosed patients suffered harm, which could have been prevented by earlier referral to neuro-ophthalmologists. Patients experienced inappropriate laboratory testing, diagnostic imaging or treatment prior to referral in 23% of cases, with higher rates for patients misdiagnosed prior to referral (34% of patients vs. 13% with a correct referral diagnosis.)

Seventy-six percent of inappropriate referrals were misdiagnosed, compared to 45% of appropriate referrals. The most common reasons for referral were optic neuritis or optic neuropathy, papilledema, diplopia or cranial nerve palsies, and unspecified vision loss. The most common sources of diagnostic error were the physical exam, generation of a complete differential diagnosis, history taking and use or interpretation of diagnostic testing.

The most common issue leading to diagnostic errors of neuro-ophthalmic conditions occurred in the physical examination, history, and the generation and consideration of the differential diagnosis.

 “These results emphasize the value of subspecialty-trained neuro-ophthalmologists in diagnosing and managing these potentially devastating conditions,” the authors noted in their study. “In almost all cases, these harms could potentially have been avoided with earlier access to neuro-ophthalmic consultation.”

But there’s one silver lining: optometrists were no worse than general ophthalmologists at neuro assessment. The study notes that there was “no meaningful difference between rates of misdiagnosis or rates of harm” between the professions.