Abstract
Purpose: :
a. Identify ophthalmologic conditions commonly misdiagnosed as an optic neuropathy and the confusing clinical features that may lead to incorrect suspicion.b. Characterize the extent of the clinical workup typically performed for these patients.c. Quantify the financial costs of evaluation for optic neuropathy.
Methods: :
Large consecutive case series, single examiner.
Results: :
Optic Neuropathy is a potentially devastating disorder that may occur in isolation or as a manifestation of a systemic disease. When a diagnosis of optic neuropathy is made or suspicion is considerable, prompt neuro-ophthalmologic evaluation is often warranted. However, the diagnosis of optic neuropathy can be complex, which may lead to referral even in situations where the diagnosis of optic neuropathy is suspect. As the workup for optic neuropathy can be extensive, referral for optic neuropathy often is accompanied by a significant financial burden. Furthermore, the implications of neurologic ocular involvement can be emotionally devastating to a patient. Therefore, it is in our best interest to ensure that referral for optic neuropathy occurs primarily in settings of the highest suspicion. To achieve this, diagnoses commonly mistaken for optic neuropathy should be identified. We have performed a retrospective analysis of 102 consecutive patients seen by a single neuro-ophthalmologist at the Wilmer Eye Institute from 2002-2008 who were referred for suspicion of optic neuropathy but did not, in fact, have the disease. Patients had an average age of 60.8 (SD = 15.9), were mostly female (71%), and were predominantly Caucasian (87%). Referral sources included general ophthalmologists, ophthalmic subspecialists, optometrists, internists, neurologists and neurosurgeons. Visual acuity, presence of a relative afferent pupillary defect, color vision, and optic nerve findings were highly variable. The vast majority of patients (>80%) had undergone prior visual field testing, and most patients had undergone prior neuroimaging (MRI or CT). Anterior segment pathology (including refractive error) and retinal pathology each accounted for 28% of referrals. Glaucoma accounted for an additional 18% of referrals. Surprisingly, 21% of patients had a normal eye examination. Incurred diagnostic costs were substantial.
Conclusions: :
Common ophthalmic diseases are frequently mistaken for an optic neuropathy. Such diagnostic errors by the referring physician suggest either a lack of understanding of the characteristics of an optic neuropathy or a concern that the physician is "missing something" and may lead to both unnecessary emotional burden for the patient and a significant cost to the health care system.
Keywords: neuro-ophthalmology: diagnosis • neuro-ophthalmology: optic nerve • visual impairment: neuro-ophthalmological disease