Prevalence and impact of neuro-ophthalmic multimorbidity on patient disposition and outcomes

As neuro-ophthalmologists often deal with uncommon disorders, the prevalence of comorbid neuro-ophthalmic diseases is unknown. This study sought to characterize the prevalence of patients diagnosed with at least two separate neuro-ophthalmologic disorders and the impact on patient disposition and outcome as of identifying the secondary diagnosis.

Retrospective chart review at two university-affiliated neuro-ophthalmic practices between July-December 2023. Sociodemographic and clinical characteristics were compared between patients with and without neuro-ophthalmic comorbidity. Diagnostic testing, patient disposition and care outcomes were collected for each diagnosis.

1843 patients (mean age 52.2 years, 62.6 % female) were identified, of whom 89 (4.8 %) were diagnosed with neuro-ophthalmic multimorbidity. The most common secondary diagnoses were thyroid eye disease (6.4 %), Horner's syndrome (5.3 %), pituitary macroadenoma (5.3 %), and trochlear nerve palsy (5.3 %). The most common symptoms and examination findings associated with neuro-ophthalmic multimorbidity were persistent vision loss, proptosis, optic nerve pallor, incomitant strabismus, ophthalmoparesis, and lid lag/retraction. The secondary diagnosis increased the urgency of neuro-ophthalmic follow-up or specialist referral in 16.9 % of patients (number needed to benefit [NNB] of 5.9) and changed the outcomes of 22.5 % of patients either by avoiding unnecessary testing/treatment or by directly saving vision/life (NNB of 4.5).

One in 21 patients referred for neuro-ophthalmic consultation was diagnosed with at least two separate neuro-ophthalmic conditions. Even within neuro-ophthalmology, a field that deals primarily with rare diseases, one must consider the possibility of multiple comorbidities when a patient's clinical presentation is atypical or inconsistent with the expected disease course.