Causes of Diplopia Include Fatal Diseases and Chronic Conditions

An ophthalmologist shines light into the eye of a tense young female patient who has a piece of foreign object (metal shard) stuck in her cornea. Real injury and examination. A slit lamp instrument for closer examination is in the foreground and lights the doctor’s hand.
Jim Williamson, OD, provides an overview of the causes of diplopia and their respective diagnostic tests and treatments.

The following article is a part of Ophthalmology Advisor’s conference coverage of the Southeastern Educational Congress of Optometry (SECO) 2021, held in Atlanta and virtually from April 28 to May 2, 2021. The team at Ophthalmology Advisor will be reporting on the presentations offered by these leading experts in optometry and ophthalmology. Check back for more from the SECO 2021 Meeting.


Ocular phenomena can be one of the first signs of a serious disease. As Jim Williamson, OD, explained in his course “Seeing Double: The Urgent and Chronic Causes of Diplopia,” at the Southeastern Educational Congress of Optometry (SECO) 2021 meeting, several causes of diplopia, or “double vision,” can be deadly.

The course offered attendees a review of the medical differential diagnosis and treatment strategies for the root causes of diplopia. Clinicians must first rule out urgent medical causes and only then consider whether a chronic cause is responsible.

Critical conditions diplopia can signal may include third nerve palsy (CNIII Palsy), granulomatosis with polyangiitis (GPA), and thyroid-associated orbitopathy (TAO).

In CNIII Palsy, intracranial aneurysms jeopardize the oculomotor nerve. While the standard of care for detecting aneurysms is cerebral digital subtraction angiography (DSA), Dr Williamson recommends a preliminary course of action using magnetic resonance angiogram (MRA) if there are no contraindications and then follow with computed tomography angiography (CTA) if no intracranial aneurysms appear.

He also reviewed vasculitides, such as GPA, polyarteritis nodosa, and giant cell arteritis (GCA).

GPA, chronic inflammation coinciding with granuloma formation, is fatal if it is not treated. Many patients have ocular and orbital symptoms, including diplopia, which is caused by affected extraocular muscles and superior orbital fissure. Dr Williamson explained appropriate testing and potential treatments, which include immunosuppressives and rituximab therapy.

Thyroid-associated orbitopathy (TAO) is another possible cause of diplopia. In this disorder, eye movement is limited because of later-stage fibrosis or extraocular muscles’ inflammation. It includes both active phases and inactive phases, and smoking can reactivate it.

Dr Williamson also covered several other diseases and conditions in the course, including traumatic brain injury (TBI), Parkinson’s disease, dragged-fovea diplopia syndrome, and supranuclear lesions, such as internuclear ophthalmoplegia (INO) and skew deviation.

While not all patients with double vision have an underlying neurological or systemic disease that could be life-threatening, it is absolutely essential for optometrists to treat each unexplained case as a priority until they can establish the patient’s immediate risk.

Visit Ophthalmology Advisor’s conference section for complete coverage of the SECO 2021 Meeting and more.



Williamson J. Seeing Double: The Urgent and Chronic Causes of Diplopia. Presented at: Southeastern Educational Congress of Optometry (SECO) 2021 Annual Meeting; April 28-May 2, 2021; Atlanta, GA. Course 120.