Editing Diplopia

{{short description|Double vision}}
{{redirect|Double vision}}
{{Infobox medical condition
| name            = Diplopia
| image           = Diplopia.jpg
| caption         = One way a person might experience double vision
| synonyms        = Double vision
| field           = [[Neurology]], [[ophthalmology]]
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'''Diplopia''' is the simultaneous [[visual perception|perception]] of two images of a single object that may be displaced in relation to each other.<ref>{{cite journal |url=https://www.ncbi.nlm.nih.gov/books/NBK441905/ |title=Diplopia | vauthors = Najem K, Margolin E  |website=National Center for Biotechnology Information |via=StatPearls |date=2021-07-18 |pmid=28722934 |access-date=2021-08-22}}</ref> Also called '''double vision''', it is a loss of visual focus under regular conditions, and is often voluntary. However, when occurring involuntarily, it results from impaired function of the [[extraocular muscles]], where both eyes are still functional, but they cannot turn to target the desired object.<ref name=osullivan>{{cite book | vauthors = O'Sullivan SB, Schmitz TJ | date = 2007 | title = Physical Rehabilitation. | location = Philadelphia, PA | publisher = Davis | isbn = 978-0-8036-1247-1}}</ref> Problems with these muscles may be due to mechanical problems, disorders of the [[neuromuscular junction]], disorders of the [[cranial nerves]] ([[Oculomotor nerve|III]], [[Trochlear nerve|IV]], and [[Abducens nerve|VI]]) that [[innervate]] the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of [[toxins]].<ref name=Blumenfeld>{{cite book | vauthors = Blumenfeld H | date = 2010 | title = Neuroanatomy through Clinical Cases. | location = Sunderland MA | publisher = Sinauer |isbn=978-0-87893-058-6}}</ref>

Diplopia can be one of the first signs of a [[systemic disease]], particularly to a muscular or neurological process,<ref name=Rucker>{{cite journal | vauthors = Rucker JC | title = Oculomotor disorders | journal = Seminars in Neurology | volume = 27 | issue = 3 | pages = 244–256 | date = July 2007 | pmid = 17577866 | doi = 10.1055/s-2007-979682 | s2cid = 260321300 }}</ref> and it may disrupt a person's balance, movement, or reading abilities.<ref name=osullivan/><ref name=kernich>{{cite journal | vauthors = Kernich CA | title = Patient and family fact sheet. Diplopia | journal = The Neurologist | volume = 12 | issue = 4 | pages = 229–230 | date = July 2006 | pmid = 16832242 | doi = 10.1097/01.nrl.0000231927.93645.34 }}</ref>

==Causes==
Diplopia has a diverse range of ophthalmologic, infectious, autoimmune, neurological, and neoplastic causes:<ref>{{Cite web|title=Diplopia - Eye Disorders|url=https://www.merckmanuals.com/en-ca/professional/eye-disorders/symptoms-of-ophthalmologic-disorders/diplopia|access-date=2021-10-27|website=Merck Manuals Professional Edition|language=en-CA}}</ref>
{{columns-list|colwidth=30em|
* [[Abscess]]
* [[Aniseikonia]]
* [[Anisometropia]]
* [[Antipsychotics]] ([[haloperidol]], [[fluphenazine]], [[chlorpromazine]] etc.)
* [[Parkinsonism|Atypical parkinsonisms]], especially [[multiple system atrophy]] and [[progressive supranuclear palsy]]
* [[Botulism]]
* [[Brain tumor]]
* [[Cannabis]]
* [[Cancer]]
* Damaged [[Oculomotor nerve|third]], [[Trochlear nerve|fourth]], or [[Abducens nerve|sixth]] cranial nerves, which control eye movements
* [[Cataract]]
* [[COVID-19]]
* [[Diabetes]]
* [[Drunkenness]]
* [[Fluoroquinolone]] antibiotics<ref name="pmid19643481">{{cite journal | vauthors = Fraunfelder FW, Fraunfelder FT | title = Diplopia and fluoroquinolones | journal = Ophthalmology | volume = 116 | issue = 9 | pages = 1814–1817 | date = September 2009 | pmid = 19643481 | doi = 10.1016/j.ophtha.2009.06.027 }}</ref>
* [[Graves disease]]<ref>{{cite web |title=Graves' Eye Disease |url=https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/graves-eye-disease |website=NIH National Eye Institute |access-date=15 April 2024}}</ref>
* [[Guillain–Barré syndrome]]
* [[Keratoconus]]
* [[LASIK#Risks|Lasik complications]]
* [[Lyme disease]]
* [[Migraine|Migraine headaches]]
* [[Multiple sclerosis]]
* [[Myasthenia gravis]]<ref>{{cite web|url=http://www.merck.com/mmpe/sec09/ch098/ch098e.html|title=Diplopia - Eye Disorders - Merck Manuals Professional Edition|website=merck.com|access-date=27 March 2018}}</ref>
* [[Myalgic encephalomyelitis/chronic fatigue syndrome]]<ref>{{cite web|url=https://www.njcfsa.org/wp-content/uploads/2010/08/4-12-Visual-Dysfunction-in-CFS.pdf|title=Visual Dysfunction in Chronic Fatigue Syndrome}}</ref>
* [[Opioids]]
* Orbital [[myositis]]
* [[Papilledema]]
* [[Physical trauma|Trauma]]
* [[Sagging eye syndrome]] (SES)<ref name="pmid31526795">{{cite journal | vauthors = Goseki T, Suh SY, Robbins L, Pineles SL, Velez FG, Demer JL | title = Prevalence of Sagging Eye Syndrome in Adults with Binocular Diplopia | journal = American Journal of Ophthalmology | volume = 209 | pages = 55–61 | date = 2020 | pmid = 31526795 | doi = 10.1016/j.ajo.2019.09.006| pmc = 6911643 }}</ref>
* [[Salicylism]]
* [[Sinusitis]]
* [[Strabismus]]<ref name="pmid35086246">{{cite journal | vauthors = Anilkumar, SE, Narendran, K | title = Prisms in the treatment of diplopia with strabismus of various etiologies | journal = Indian Journal of Ophthalmology | volume = 70 | issue = 2 | pages = 609–612 | date = 2022 | pmid = 35086246 | doi = 10.4103/ijo.IJO_939_21| pmc = 9023992 | doi-access = free }}</ref>
* [[Thyroid eye disease]] (TED)<ref name="pmid33278144">{{cite journal | vauthors = Johnson, Brooke T, Jameyfield, E, Aakalu, VK | title = Optic neuropathy and diplopia from thyroid eye disease update on pathophysiology and treatment | journal = Current Opinion in Neurology | volume = 34 | issue = 1 | pages = 116–121 | date = 2021 | pmid = 33278144 | doi = 10.1097/WCO.0000000000000894 | pmc = 7853658 }}</ref>
* [[Wernicke's encephalopathy|Wernicke's syndrome]]
* Increased intracranial pressure (compressing the sixth cranial nerve results in diplopia)
}}
*

==Diagnosis==
Diplopia is diagnosed mainly by information from the patient. Doctors may use [[blood test]]s, physical examinations,<ref>{{cite journal | vauthors = Low L, Shah W, MacEwen CJ | title = Double vision | journal = BMJ | volume = 351 | pages = h5385 | date = November 2015 | pmid = 26581615 | doi = 10.1136/bmj.h5385 | s2cid = 28083094 }}</ref> [[computed tomography]] (CT), or [[magnetic resonance imaging]] (MRI) to find the underlying cause.<ref>{{Cite web  | vauthors = Seltman W | date = 30 March 2020 |url=https://www.webmd.com/eye-health/double-vision-diplopia-causes-symptoms-diagnosis-treatment#2-3 |title=An Overview of Double Vision |website=WebMD |language=en-US |access-date=2018-09-23}}</ref>

===Classification===

One of the first steps in diagnosing diplopia is often to see whether one of two major classifications may be eliminated. That involves blocking one eye to see which symptoms are evident in each eye alone. Persisting blurry or double vision with one eye closed is classified as monocular diplopia.<ref name=Karmel>{{cite web | vauthors = Karmel M| title= Deciphering Diplopia | newspaper= EyeNet | date = November 2009 | url=https://www.aao.org/Assets/ea95f20c-82a6-47b0-9f40-bba381a97941/635596088591000000/feature-nov-dec-2009-pdf |url-status=dead |archive-url=https://web.archive.org/web/20160316113719/http://www.aao.org/eyenet/article/deciphering-diplopia?novemberdecember-2009 |archive-date=March 16, 2016}}</ref>

=== Binocular ===

Binocular diplopia is the other one in which the blurring of vision occurs only when the patient looks through both eyes simultaneously. It is common and occurs in approximately 10.0% to 40.0% of zygomatic complex injuries. Furthermore, diplopia may be transient or persistent. Inadequate diagnosis and treatment at improper times and tethering or fibrosis of muscles may lead to persistent diplopia.<ref>Shabbir, M., Shah, R., Ahmad, M., Issrani, R., Khan, Z., Salah, N. A. Qayyum, Z. (2023). Frequency of diplopia in zygomatic complex Fractures—A cross-sectional descriptive study. ''International Journal of Dentistry''. https://doi.org/10.1155/2023/7631634</ref>

Binocular diplopia is double vision arising as a result of [[strabismus]]<ref>{{cite journal | vauthors = Peragallo JH, Pineles SL, Demer JL | title = Recent advances clarifying the etiologies of strabismus | journal = Journal of Neuro-Ophthalmology | volume = 35 | issue = 2 | pages = 185–193 | date = June 2015 | pmid = 25724009 | pmc = 4437883 | doi = 10.1097/WNO.0000000000000228 }}</ref> (in layman's terms "cross-eyed"), the misalignment of the two eyes relative to each other, either [[esotropia]] (inward) or [[exotropia]] (outward). In such a case while the [[Fovea centralis|fovea]] of one eye is directed at the object of regard, the fovea of the other is directed elsewhere, and the image of the object of regard falls on an extrafoveal area of the [[retina]]. Acute diplopia is a diagnostic challenge. The most common cause of acute diplopia are ocular motor nerve palsies (OMP).<ref>{{cite journal | vauthors = Kremmyda O, Frenzel C, Hüfner K, Goldschagg N, Brem C, Linn J, Strupp M | title = Acute binocular diplopia: peripheral or central? | journal = Journal of Neurology | volume = 267 | issue = Suppl 1 | pages = 136–142 | date = December 2020 | pmid = 32797299 | pmc = 7718182 | doi = 10.1007/s00415-020-10088-y }}</ref>

The brain calculates the visual direction of an object based upon the position of its image relative to the fovea. Images falling on the fovea are seen as being directly ahead, while those falling on retina outside the fovea may be seen as above, below, right, or left of straight ahead depending upon the area of retina stimulated. Thus, when the eyes are misaligned, the brain perceives two images of one target object, as the target object simultaneously stimulates different, noncorresponding, retinal areas in either eye, thus producing double vision.<ref>{{cite journal | vauthors = Jain S | title = Diplopia: Diagnosis and management | journal = Clinical Medicine | volume = 22 | issue = 2 | pages = 104–106 | date = March 2022 | pmid = 35304368 | doi = 10.7861/clinmed.2022-0045 | pmc = 8966821 }}</ref>

This correlation of particular areas of the retina in one eye with the same areas in the other is known as [[retinal correspondence]]. This relationship also gives rise to an associated phenomenon of binocular diplopia, although one that is rarely noted by those experiencing diplopia. Because the fovea of one eye corresponds to the fovea of the other, images falling on the two foveae are projected to the same point in space. Thus, when the eyes are misaligned, two different objects will be perceived as superimposed in the same space. This phenomenon is known as 'visual confusion'.<ref>{{cite book | vauthors = Buffenn AN | chapter = Diplopia and Strabismus |date=2020  | title = Albert and Jakobiec's Principles and Practice of Ophthalmology |pages=1–20 | veditors = Albert D, Miller J, Azar D, Young LH |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-90495-5_291-1 |isbn=978-3-319-90495-5  | s2cid = 236868860 }}</ref>

The brain naturally guards against double vision. In an attempt to avoid double vision, the brain can sometimes ignore the image from one eye, a process known as [[Suppression (eye)|suppression]]. The ability to suppress is to be found particularly in childhood when the brain is still developing. Thus, those with childhood strabismus almost never complain of diplopia, while adults who develop strabismus almost always do.  This ability to suppress might seem an entirely positive adaptation to strabismus, but in the developing child it can prevent the proper development of vision in the affected eye, resulting in [[amblyopia]]. Some adults are also able to suppress their diplopia, but their suppression is rarely as deep or as effective and takes much longer to establish; thus, they are not at risk of permanently compromising their vision. In some cases, diplopia disappears without medical intervention, but in other cases, the cause of the double vision may still be present.

Certain people with diplopia who cannot achieve fusion and yet do not suppress may display a certain type of [[spasm]]-like irregular movement of the eyes in the vicinity of the fixation point (see: [[Horror fusionis]]).

=== Monocular ===
Diplopia can also occur when viewing with only one eye; this is called monocular diplopia, or where the patient perceives more than two images, monocular polyopia. While serious causes rarely may be behind monocular diplopia symptoms, this is much less often the case than with binocular diplopia.<ref name=Karmel /> The differential diagnosis of multiple image perception includes the consideration of such conditions as corneal surface [[keratoconus]], [[subluxation]] of the lens, a structural defect within the eye, a lesion in the anterior [[visual cortex]], or nonorganic conditions, but diffraction-based (rather than geometrical) optical models have shown that common optical conditions, especially [[astigmatism]], can also produce this symptom.<ref name=Archer>{{Citation | journal= Trans Am Ophthalmol Soc. | date=December 2007|volume= 105 |pages= 252–271 |author=Steven M. Archer, MD |pmc= 2258122 |title=Monocular Diplopia Due To Spherocylindrical Refractive Errors |pmid=18427616}}</ref>

=== Temporary ===
Temporary binocular diplopia can be caused by [[alcohol intoxication]] or head injuries, such as [[concussion]] (if temporary double vision does not resolve quickly, one should see an [[optometrist]] or [[ophthalmologist]] immediately). It can also be a side effect of [[benzodiazepines]] or [[opioids]], particularly if used recreationally in larger doses, the [[antiepileptic]] drugs [[phenytoin]], [[zonisamide]] and [[lamotrigine]], as well as the [[hypnotic]] drug [[zolpidem]] and the [[dissociative]] drugs [[ketamine]] and [[Recreational use of dextromethorphan|dextromethorphan]]. Temporary diplopia can also be caused by tired or [[Eye strain|strained eye muscles]].<ref>{{cite journal | vauthors = Kaur K, Gurnani B, Nayak S, Deori N, Kaur S, Jethani J, Singh D, Agarkar S, Hussaindeen JR, Sukhija J, Mishra D | display-authors = 6 | title = Digital Eye Strain- A Comprehensive Review | journal = Ophthalmology and Therapy | volume = 11 | issue = 5 | pages = 1655–1680 | date = October 2022 | pmid = 35809192 | doi = 10.1007/s40123-022-00540-9 | pmc = 9434525 }}</ref> If diplopia appears with other symptoms such as fatigue and acute or chronic pain, the patient should see an ophthalmologist immediately.<ref>{{cite journal | vauthors = Davenport M, Condon B, Lamoureux C, Phipps Johnson JL, Chen J, Rippee MA, Zentz J | title = The University of Kansas Health System Outpatient Clinical Concussion Comprehensive Protocol: An Interdisciplinary Approach | journal = Health Services Insights | volume = 15 | pages = 11786329221114759 | date = Jan 2022 | pmid = 36034733 | doi = 10.1177/11786329221114759 | pmc = 9411741 }}</ref><ref name = "MedlinePlus">{{Cite encyclopedia |title=Cranial mononeuropathy VI | encyclopedia = MedlinePlus Medical Encyclopedia |url=https://medlineplus.gov/ency/article/000690.htm |access-date=2023-01-17 | publisher = U.S. National Library of Medicine |language=en}}</ref>

=== Voluntary ===
Some people are able to consciously uncouple their eyes, either by overfocusing closely (i.e., going cross-eyed) or unfocusing. Also, while looking at one object behind another object, the foremost object's image is doubled (for example, placing one's finger in front of one's face while reading text on a computer monitor). In this sense, double vision is neither dangerous nor harmful, and may even be enjoyable. It makes viewing [[stereoscopy|stereogram]]s possible.<ref>{{cite web | url = http://www.focusillusion.com/Instructions/ | archive-url = https://web.archive.org/web/20061023020433/http://www.focusillusion.com/Instructions/ | archive-date = 23 October 2006 | title = Instructions on how to view stereograms such as magic eye | work = FocusIllusion.com }}</ref>

Monocular diplopia may be induced in many individuals, even those with normal eyesight, with simple defocusing experiments involving fine, high-contrast lines.<ref name=Archer />

==Treatment==
{{original research|date=April 2021}}
The appropriate treatment for binocular diplopia depends upon the cause of the condition producing the symptoms. Efforts must first be made to identify and treat the underlying cause of the problem. Treatment options include eye exercises,<ref name=osullivan/> wearing an eye patch on alternative eyes,<ref name=osullivan/><ref name = "MedlinePlus" /> [[prism correction]],<ref name=Philips>{{cite journal | vauthors = Phillips PH | title = Treatment of diplopia | journal = Seminars in Neurology | volume = 27 | issue = 3 | pages = 288–298 | date = July 2007 | pmid = 17577869 | doi = 10.1055/s-2007-979680 | s2cid = 260316797 }}</ref><ref name = "MedlinePlus" /><ref>{{cite journal | vauthors = Anilkumar SE, Narendran K | title = Prisms in the treatment of diplopia with strabismus of various etiologies | journal = Indian Journal of Ophthalmology | volume = 70 | issue = 2 | pages = 609–612 | date = February 2022 | pmid = 35086246 | pmc = 9023992 | doi = 10.4103/ijo.IJO_939_21 | doi-access = free }}</ref> and in more extreme situations, surgery<ref name=kernich/> or [[botulinum toxin]].<ref name=Taub>{{cite journal | vauthors = Taub MB |year=2008|title= Botulinum toxin represents a new approach to managing diplopia cases that do not resolve | journal = Journal of the American Optometric Association| volume = 79|issue=4|pages= 174–175 | doi = 10.1016/j.optm.2008.01.003 }}</ref>  If your provider diagnoses swelling or inflammation of, or around the nerve, medicines called corticosteroids may be used.

Sometimes, the condition disappears without treatment. People with diabetes may be advised to keep tight control of their blood sugar level.

The provider may prescribe an eye patch to relieve the double vision. The patch can be removed after the nerve heals.

Surgery or special glasses (prisms) may be advised if there is no recovery in 6 to 12 months.

If diplopia turns out to be intractable, it can be managed as last resort by obscuring part of the patient's field of view. This approach is outlined in the article on diplopia occurring in association with a condition called [[horror fusionis]].

== See also ==
* [[Binocular vision]]
* [[Monocular rivalry]]
* [[Orthoptics]]

== References ==
{{Reflist}}

== Further reading ==
* {{cite journal | vauthors = Fraine L | title = Nonsurgical management of diplopia | journal = The American Orthoptic Journal | volume = 62 | pages = 13–18 | year = 2012 | pmid = 23002469 | doi = 10.3368/aoj.62.1.13 | s2cid = 218549699 }}

== External links ==
{{Medical resources
|  DiseasesDB     = 31225
|  ICD10          = {{ICD10|H|53|2|h|53}}
|  ICD9           = {{ICD9|368.2}}
|  ICDO           =
|  OMIM           =
|  MedlinePlus    =
|  eMedicineSubj  = oph
|  eMedicineTopic = 191
|  MeshID         = D004172
}}
* [https://web.archive.org/web/20151208161955/http://www.aao.org/eyenet/article/deciphering-diplopia?novemberdecember-2009 Deciphering Diplopia]

{{Wiktionary|diplopia}}
{{Eye pathology}}

[[Category:Visual disturbances and blindness]]
[[Category:Vision]]