History and Physical

38F with no medical history, presenting with double vision. The patient reported six weeks of intermittent diplopia for which she had presented to this hospital previously. She was briefly admitted for evaluation of possible cranial nerve IV palsy. Extensive imaging was unremarkable, without mass lesion, infarction, vascular malformation, or meningeal enhancement. She was discharged with outpatient follow-up including ophthalmology clinic and further imaging.

The patient represented due to persistent diplopia that is worse with right gaze. The diplopia is predominantly vertical, alleviated by head tilt. Now associated with three days of right ptosis as well as two weeks of progressive weakness and fatigue – most notable when climbing stairs.

Examination notable for right hypertropia increased on right or downward gaze suggestive of isolated inferior rectus weakness. Pupils were equal and reactive. There was marked fatigable ptosis with 2mm right palpebral fissure compared to 10mm on contralateral side. Symmetrical muscle weakness was noted, 4/5 neck flexion, elbow extension, wrist flexion/extension, shoulder abduction, hip flexion. Gait was wide-based. Application of ice for 5 minutes improved right palpebral fissure opening to >7mm.

Further evaluation included CXR and CT chest with intravenous contrast which did not identify a mediastinal mass. The patient’s respiratory status remained stable throughout hospitalization as assessed by measurements of forced vital capacity. On hospital day one, an edrophonium test was performed which was positive. The patient was started on pyridostigmine, completed a course of IVIG and was discharged with outpatient neurology follow-up.

Evaluation of Diplopia 1


  1. Onset/cadence
  2. Direction of gaze with worst diplopia
  3. Orientation (vertical/horizontal)
  4. Associated symptoms (headache, vertigo, dysarthria, eye pain)

Terms Describing Eye Position

Terms describing eye position

Tropias are always present, phorias are identified by cross-cover testing (break fusion)

Algorithm for the Evaluation of Diplopia 2

Algorithm for the Evaluation of Diplopia

Causes of Diplopia 3,4,5,6

Finding EOM Causes Features
Mechanical orbitopathy Variable. Abrupt restriction of movement Orbital cellulitis Pain, erythema
Orbital pseudotumor Autoimmune
Trauma History
Thyroid eye disease Bilateral
Isolated CN III Limited adduction/upgaze/downgaze Microvascular ischemia Pain, risk factors, pupil-sparing
Aneurysm Pupil involvement
Demyelination MRI
Isolated CN IV Limited downgaze (hypertropia) Trauma May be mild
Microvascular ischemia Less common than CN III
ICP Fundoscopy, imaging
Demyelination MRI
Isolated CN VI Limited abduction


ICP Fundoscopy, imaging
Demyelination MRI
Microvascular ischemia Less common than CN III
INO Limited adduction


Demyelination MRI
Stroke Dysarthria, ataxia, facial weakness
Multiple CN involvement (III, IV, VI) Variable Cavernous sinus process Retroorbital pain, conjunctival injection or chemosis
Brainstem deficits Variable Brainstem stroke Weakness, dysmetria, tremor
Basilar artery occlusion Vertigo, slurred speech
Wernicke AMS, ataxia, nystagmus
Basilar meningitis Fever, photophobia, meningismus
Miller-Fisher Ataxia, areflexia
Neuromuscular process Variable Myasthenia gravis Fatigability, ice test


  1. Alves, M., Miranda, A., Narciso, M. R., Mieiro, L., & Fonseca, T. (2015). Diplopia: a diagnostic challenge with common and rare etiologies. The American journal of case reports, 16, 220–223. doi:10.12659/AJCR.893134
  2. Borooah, S., Wright, M., & Dhillon, B. (2011). Pocket Tutor Ophthalmology. JP Medical Limited. Retrieved from https://books.google.com/books?id=z\_CfWj8-ftoC
  3. Dinkin, M. (2014). Diagnostic approach to diplopia. Continuum (Minneapolis, Minn.), 20(4 Neuro-ophthalmology), 942–965. doi:10.1212/01.CON.0000453310.52390.58
  4. Rucker, J. C., & Tomsak, R. L. (2005). Binocular diplopia. A practical approach. The neurologist, 11(2), 98–110. doi:10.1097/01.nrl.0000156318.80903.b1
  5. Friedman, D. I. (2010). Pearls: diplopia. Seminars in neurology, 30(1), 54–65. doi:10.1055/s-0029-1244995
  6. Guluma, K. (2013). Diplopia. In Rosen’s Emergency Medicine – Concepts and Clinical Practice (8th ed., Vol. 1, pp. 176-183). Elsevier Health Sciences.
  7. WikEM: Diplopia

Conjunctivitis and the Red Eye

Differential diagnosis of Conjunctivitis 1,2,3

Condition Pain Visual Acuity Photophobia Discharge Conjunctiva Lymphadenopathy Laterality Associated Features
Viral conjunctivitis None Unaffected None + watery ++ follicular pattern Pre-auricular Unilateral, spreads bilateral Viral URI
Bacterial conjunctivitis None Unaffected None ++ purulent +++ papillary pattern Occasional Unilateral, spreads bilateral Otitis media
Allergic conjunctivitis None Unaffected None + mucoid + None Bilateral Atopy

Differential Diagnosis of Red Eye 4,5

Condition Comment Hyperemia Pupil Pain Visual Acuity Cornea
Subconjuntival hemorrhage Subconjunctival Hemorrhage Associated with trauma, coagulopathy, hypertension. Unilateral, sharply circumscribed Unaffected None Unaffected Clear
Blepharitis Blepharitis Acute/chronic inflammation of eyelid. Diffuse Unaffected Foreign body sensation Unaffected Clear
Epislceritis Episcleritis Recurrent, self-limited episodes, possible autoimmune association. Engorged, radially-oriented vessels Unaffected Mild Unaffected Clear
Scleritis Scleritis Vascular or connective tissue disease. Focal or diffuse, pink sclera Unaffected Moderate Reduced Clear
Acute angle-closure glaucoma Acute Angle-Closure Glaucoma Mydriasis leading to decreased outflow of aqueous humor. Circumcorneal injection Semi-dilated Severe Reduced Hazy
Acute anterior uveitis Uveitis Inflammation of iris or ciliary body. Circumcorneal injection Constricted Moderate Reduced Hazy
Keratitis Keratitis Inflammation of corneal epithelium. Caused by infection, contact lenses, UV exposure. Multiple punctate erosions, stain with fluorescein Unaffected Moderate Reduced Hazy

Algorithm for the Evaluation of the Red Eye 6

Algorithm for the Evaluation of the Red Eye


  1. Teoh, D. L., & Reynolds, S. (2003). Diagnosis and management of pediatric conjunctivitis. Pediatric emergency care, 19(1), 48–55.
  2. Azari, A. A., & Barney, N. P. (2013). Conjunctivitis. JAMA: the journal of the American Medical Association, 310(16), 1721. doi:10.1001/jama.2013.280318
  3. Cronau, H., Kankanala, R. R., & Mauger, T. (2010). Diagnosis and management of red eye in primary care. American family physician, 81(2), 137–144.
  4. Leibowitz, H. M. (2000). The red eye. New England Journal of Medicine, 343(5), 345–351. doi:10.1056/NEJM200008033430507
  5. Richards, A., & Guzman-Cottrill, J. A. (2010). Conjunctivitis. Pediatrics in review / American Academy of Pediatrics, 31(5), 196–208. doi:10.1542/pir.31-5-196
  6. Borooah, S., Wright, M., & Dhillon, B. (2011). Ophthalmology. JP Medical Limited.