Article Text

Download PDFPDF
New-onset partial ptosis and double vision
  1. Jason M Kwok1,
  2. Jonathan A Micieli1,2
  1. 1 Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
  2. 2 Kensington Vision and Research Centre, Toronto, Ontario, Canada
  1. Correspondence to Dr Jonathan A Micieli, Kensington Eye Institute, Toronto, ON M5T 3A9, Canada; jonathanmicieli{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Clinical introduction

A 70-year-old woman presented to the emergency room with a 1-day history of right periorbital pain, ptosis and binocular horizontal diplopia when looking to the left. Visual acuity was 20/20 in both eyes and external examination revealed partial right ptosis. Assessment of ocular motility revealed a mild limitation of elevation, depression and adduction in the right eye only (figure 1). Pupils were of equal sizes and reactive to light (figure 1). Cranial nerve function and neurological examination were otherwise normal. CT angiography (CTA) of the brain was performed, demonstrating an intracranial aneurysm.

Figure 1

Ocular motility photographs demonstrating mild limitation of elevation, depression and adduction in the right eye only (red circles). There is full ocular motility in the left eye. Partial ptosis (yellow arrow) is seen. The pupils are of equal sizes.


Where is the most likely location of an aneurysm causing this condition?

  1. Basilar artery.

  2. Posterior cerebral artery at the junction of the posterior communicating (Pcomm) artery.

  3. Pcomm artery at the junction of the internal carotid artery (ICA).

  4. Cavernous carotid artery.


C. Pcomm artery at the junction of the internal carotid artery (ICA).

The combination of right ptosis and limitation of elevation, depression and adduction of the right eye indicates dysfunction of the third cranial nerve (CN3), which innervates the levator palpebrae superioris, superior rectus, inferior rectus and medial rectus muscles.

A third nerve palsy (3 NP) may be the presenting sign of an intracranial aneurysm, and a CTA of the brain is required in all new cases.1 This patient had an aneurysm at the junction of the Pcomm artery and the ICA, which is the most common location for those causing 3 NP (figure 2).2 When aneurysms cause new neurological symptoms, it suggests that their morphology is changing and they are at high risk of rupture.2

Figure 2

CT angiography (left) demonstrating a right posterior communicating artery aneurysm (red arrow). CT postneurosurgical report demonstrating an aneurysm clip (yellow arrow) in the location of the previous aneurysm.

The presence of pupillary dilation in the setting of a 3 NP is highly indicative of a compressive lesion involving CN3. However, an aneurysm may present with normal pupils especially when the 3 NP is partial.3 Urgent neuroimaging (CTA or magnetic resonance angiography) should be performed in all suspected cases of 3 NP regardless of the pupillary examination. The Pcomm-ICA aneurysm usually extends inferolaterally to compress the dorsomedially located pupillary fibres on CN3. Pupil sparing may be explained by more laterally placed parasympathetic fibres or aneurysms approaching the nerve inferiorly or superiorly.3



  • Contributors Conception and design: JMK and JAM; data acquisition: JMK and JAM; manuscript preparation: JMK; critical revision: JAM; final approval: JMK and JAM.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Patient consent for publication Obtained.

  • Provenance and peer review Not commissioned; internally peer reviewed.