SAEM Clinical Images Series: Two Pupils for the Price of One

pupil

A 24-year-old female with no pertinent PMHx presents to the ED with a chief complaint of eye pain. She reported a 10-day history of worsening right eye pain following being punched in that eye. She had been managing her pain with ice and had not taken any OTC medications. Her mom convinced her to go to the ED and she first went to an outside hospital, but was referred to come to our institution. She endorsed photophobia and blurry vision but denied double vision. She further noted occasional left-sided headaches.

Vitals: Within normal limits

General: The patient is alert and conversant. No apparent distress.

HEENT: NC, AT. Mucous membranes moist. Neck supple. Minimal pain with EOM. No double vision in right eye. Right eye discoloration at superior portion. Divided abnormal pupil. Mild superior periorbital swelling. Visual acuity: Right – 20/400, Left – 20/25

CV: Regular rate and rhythm.

Resp: Clear to auscultation bilaterally.

Abd: Soft, non-tender, non-distended.

Neuro: Alert. Motor and sensation grossly intact.

MSK: Moves all extremities, no joint pain or tenderness.

Skin: No obvious rashes or skin lesions.

Non-contributory

This is traumatic iridodialysis. It is typically related to significant blunt trauma to the eye that pulls the iris away from the ciliary body at the scleral spur [1]. That is what causes the split appearance or “two pupil” phenomenon.

Take-Home Points

  • Whenever you have a two-pupil phenomenon consistent with traumatic iridodialysis, the differential should always include penetrating injury to the globe, globe rupture, scleral rupture, hyphema, and lens dislocation. These additional findings may warrant urgent surgical repair or close monitoring of IOP. [2]
  • Consider bedside ultrasound to rule out posterior pathology (retinal detachment, vitreous hemorrhage, etc.).
  • Always refer to Ophthalmology, more urgently if the trauma was recent vs multiple days out (as in this case).
  • Knoop KJ, Palma JK. Iridodialysis. In: Knoop KJ, Stack LB, Storrow AB, Thurman R. eds. The Atlas of Emergency Medicine, 5e. McGraw Hill; 2021. https://accessmedicine.mhmedical.com/content.aspx?bookid=2969&sectionid=250455915
  • Gurwood AS. Cut at the root. Review of Optometry. https://www.reviewofoptometry.com/article/cut-at-the-root. Published November 19, 2012. Accessed January 2023.