27th December 2023

Presentation

Both monocular and binocular diplopia can present in the same way with a history of double vision, where single objects appear as double in the horizontal, vertical, or oblique plane. Binocular diplopia tends to present as two clearly separated images, whereas monocular presentations describe a ‘ghost image’ or a second slightly faded image, which may partly overlap the true image.

The onset of diplopia is almost always sudden and, depending on the underlying cause, can worsen or improve over time. Because of its sudden onset, diplopia can often be presumed to have a vascular cause, but it is important to keep a broad differential list. The progression of the diplopia can be quite telling; for example, changes in the pattern and intensity of diplopia point towards pathology such as compression, whereas intermittent diplopia with diurnal variation points more towards neuromuscular junction disorders like myasthenia gravis.

Patients may also present with compensatory mechanisms such as head tilts, which they do to reduce the double vision phenomenon. When the diplopia is secondary to uncorrected strabismus, patients may present with obvious squint, which is not necessarily the presenting complaint.

In cases of diplopia secondary to pathologies such as myasthenia gravis or thyroid eye disease, patients may present with diplopia later in the day or worse in the morning, respectively. Patients with Parkinson’s Disease can present with diplopia secondary to convergence insufficiency, where there is a horizontal diplopia after prolonged periods of near vision tasks such as reading. These patients may present with letters that ‘mix together’ on the page or screen.

The past medical and family history may include vascular risk factors such as hypertension, diabetes or cardiac disease, and specific ophthalmology questions may highlight issues in childhood or even ongoing in adulthood, such as strabismus corrected with prisms or surgery. It is important to explore ocular trauma, headache history, control of any comorbidities such as hypertension and diabetes, and a drug history such as citalopram, lamotrigine, and gabapentin have been associated with diplopia.

Signs

Source: Wikimedia Commons (2019). StrabismusVL2, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/w/index.php?curid=81253483 (Accessed on: 13 February 2023).

Source: Wikimedia Commons (2017). Proptosis and lid retraction from Graves’ Disease, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/w/index.php?curid=16115992 (Accessed on: 13 February 2023).

Source: Wikimedia Commons (2009). Congenitalptosis, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Congenitalptosis.JPG (Accessed on: 13 February 2023).

References

• Iliescu DA, Timaru CM, Alexe N, Gosav E, De Simone A, Batras M, Stefan C. Management of diplopia. Romanian journal of ophthalmology. 2017 Jul;61(3):166.
• Jitander Dudee MD. Diplopia (Double Vision) clinical presentation [Internet]. History, Physical, Causes. Medscape; 2022 [cited 2023Feb9]. Available from: https://emedicine.medscape.com/article/1214490-clinical