Diplopia [ ] Monocular (monocular if diplopia present even when only 1 eye open) vs [ ] Binocular (binocular only when both eyes open)

Causes If painful, think of the following: Red Flags

Monocular diplopia Binocular diplopia usually d/t something usually d/t disconjugate Compressive lesion/tumor/aneurysm >1 cranial nerve deficit distorting light through alignment of eyes eye to retina Sinusitis/abscess/cavernous sinus thrombosis Pupillary involvement cataract CN palsy (3rd, 4th, 6th) corneal shape problems Myasthenia gravis Orbital myositis Other neurologic s/s alongwith diplopia (keratoconus) uncorrected refractive Orbital infiltration (e.g. Trauma (fracture/hematoma) Pain error (usually thyroid infiltrative astigmatism) ophthalmopathy, orbital pseudotumor) Skull base tumors (pain often unrelated to eye movement) Proptosis other: corneal scarring, Other causes: CVA dislocated lens, affecting pons/midbrain; malingering compressive lesion (aneurysm, tumor); History idiopathic; inflammatory/infectious (sinusitis, cavernous sinus monocular vs binocular? gait difficulties (CN 8) thrombosis, abscess); Wernicke’s ; orbital myositis; trauma intermittent or constant? difficulty with bladder control (MS) (fracture, hematoma); tumors near base of skull/sinuses/orbits; images separated horizontally or vertically or a weakness/sensory abnormalities (intermittent or botulism; GBS/Miller- combination of both? constant) Fisher; MS

vision changes? (CN2) N/V/diarrhea (botulism)

Key points numbness of forehead/face/cheek (CN5) swallowing or speech difficulties (CN 9, 12) Isolated pupil-sparing nerve palsy with no other s/s may resolve spontaneously facial weakness (CN 7) palpitations, heat insensitivity, weight loss (Graves’ disease)

Do imaging if any red flags dizziness (CN 8) PMH: HTN, DM or both (risk factors for CVA)

Focal weakness in any muscle may indicate neuromuscular hearing loss (CN 8) PMH: alcohol abuse (Wernicke’s) problem Eye Exam Specific findings/clues to etiology:

Ptosis, eye deviated laterally and down, +/- CN 3 Visual acuity (each eye separately, then Fundoscopy? (cataract, lens displacement, pupillary dilation both together to determine if monocular retina, disc) or binocular) Vertical diplopia worse on downward gaze (patient CN 4 will tilt head to improve vision) Bulging/proptosis? EOMs (mild paresis may not be evident on exam) Eye deviated medially, diplopia worse on lateral CN 6 gaze, patient turns head to improve vision Ptosis? Rest of Neuro exam findings: Intermittent diplopia MG or MS or unmasking of latent phoria (eye deviation) Pupillary abnormalities? Pupillary abnormality on convergence? INO: on horizontal gaze, there is weak adduction on MLF lesion (MS) affected side (cannot adduct past midline) and Disconjugate eye movements? Goiter? (Graves’) nystagmus of contralateral eye. Affected eye will converge normally Nystagmus? Pretibial myxedema on shins (Graves’) Older patient, DM, HTN, atherosclerosis CVA

If diplopia in 1 direction of gaze: place red If no red glass, have patient close one eye: Sudden pain/headache Aneurysm glass over one eye – the image that is the paretic eye is the one that when more peripheral is from paretic eye so if closed causes the more peripheral image Constant pain, sometimes fever or systemic Infection/inflammatory lesions including peripheral image is red, the red glass is to disappear complaints, facial sensory changes, proptosis abscess/cavernous sinus thrombosis over paretic eye H/o alcohol abuse, ataxia, confusion Wernicke’s

Exophthalmos, eye pain/irritation, photophobia, Graves’ disease goiter, pretibial myxedema Management/workup: Constant eye pain worsening with eye movement, Orbital myositis If monocular diplopia: Refer to Ophthalmology corneal injection, proptosis H/o or s/s of trauma Trauma/hematoma/fracture If unilateral, single cranial nerve palsy, normal pupillary reflexes, no other s/s: observe w/o testing for a few Pain unrelated to eye motion, unilateral proptosis, Tumors weeks. Most will resolve spontaneously. Ophthalmology other neurologic s/s evaluation +/- GI s/s, descending weakness, other cranial nerve Botulism dysfunction, dilated pupils, normal sensation If other s/s, usually will need imaging (CT/MRI – do not do Binocular: Ataxia, reduced reflexes GBS, Miller-Fisher MRI if intraocular metallic foreign body suspected) – do STAT if suspecting infection, CVA, tumor/aneurysm Intermittent s/s, migratory neuro s/s, paresthesias, MS visual disturbance, urinary dysfunction, INO

If s/s thyroid disease, do TSH, fT4 Intermittent diplopia, ptosis, bulbar s/s, weakness MG that worsens on repetition

intermittent diplopia: test for MG or MS No other manifestations other than diplopia Idiopathic, r/o infiltrative tumors of extra-ocular muscles