- Eye vs Brain– Evie Marcolini, MD and Anand Swaminathan, MD
- Diplopia easy to distinguish, monocular diplopia most likely ocular pathology, whereas binocular diplopia is usually CNS .
- Cranial Nerve Palsy: 3, 4, 6 (think SAH when CN 3 palsy, abduction only -no adduction, supraduction or infraduction, with acute HA)
- Internuclear Ophthalmoplegia
- Hard to distinguish between ocular and CNS pathology with painless, non-red, non-post-op, atraumatic monocular vision loss!
- Uptodate has a nice algorithm for monocular vision loss.
- The challenge is the ddx for painless, non-red, non-post-op, atraumatic monocular vision loss includes both ocular and CNS etiology.
- Ocular: lens, vitreous hemorrhage, posterior uveitis, acute maculopathy, retinal detachment (peripheral or central loss), retinal vein occlusion, ischemic optic neuropathy (eg temporal arteritis).
- CNS- retinal or ophthalmic artery occlusion
- If after exam, history and ultrasound you’re not sure, patient needs transfer to tertiary center with both neurology and ophthalmology.
- Diplopia easy to distinguish, monocular diplopia most likely ocular pathology, whereas binocular diplopia is usually CNS .