STUDY - Technical - New Dacian's Medicine
Diplopia
(Classical / Allopathic Medicine)
Diplopia is double
vision — seeing one object as two. This symptom results when
extraocular muscles fail to work together, causing images to
fall on noncorresponding parts of the retinas. Orbital
lesions, the effects of surgery, or impaired function of
cranial nerves that supply extraocular muscles (oculomotor, CN
III; trochlear, CN IV; abducens, CN VI) may be responsible for
this muscular incoordination. (See Testing extraocular
muscles.)
Diplopia usually
begins intermittently and affects near or far vision
exclusively. It can be classified as monocular or binocular.
More common binocular diplopia may result from ocular
deviation or displacement, extraocular muscle palsies, or
psycho-neurosis, or it may occur after retinal surgery.
Monocular diplopia may result from an early cataract, retinal
edema or scarring, iridodialysis, a subluxated lens, a poorly
fitting contact lens, or an uncorrected refractive error such
as astigmatism. Diplopia may also occur in those with hysteria
or malingering.
HISTORY:
Ask the patient when he first noticed the diplopia.
Ask the patient whether the images are side-by-side (horizontal), one above the other (vertical), or a combination. Ask him if it affects his near or far vision. Does it affect certain directions of gaze?
Ask the patient whether the diplopia has worsened, remained the same, or subsided. Does its severity change throughout the day?
Ask the patient about associated signs and symptoms, especially a severe headache. Also ask him about eye pain, hypertension, diabetes mellitus, allergies, and thyroid, neurologic, or muscular disorders.
Review the patient's medical history for extraocular muscle disorders, trauma, or eye surgery.
Ask the patient when he first noticed the diplopia.
Ask the patient whether the images are side-by-side (horizontal), one above the other (vertical), or a combination. Ask him if it affects his near or far vision. Does it affect certain directions of gaze?
Ask the patient whether the diplopia has worsened, remained the same, or subsided. Does its severity change throughout the day?
Ask the patient about associated signs and symptoms, especially a severe headache. Also ask him about eye pain, hypertension, diabetes mellitus, allergies, and thyroid, neurologic, or muscular disorders.
Review the patient's medical history for extraocular muscle disorders, trauma, or eye surgery.
Testing
extraocular muscles
The coordinated action of six muscles controls eyeball movements. To test the function of each muscle and the cranial nerve (CN) that innervates it, ask the patient to look in the direction controlled by that muscle. The six directions you can test make up the cardinal fields of gaze. The patient's inability to turn the eye in the designated direction indicates muscle weakness or paralysis.
SR — superior rectus (CN III)
IR — inferior rectus (CN III)
MR — medial rectus (CN III)
LR — lateral rectus (CN VI)
IO — inferior oblique (CN III)
SO — superior oblique (CN IV)
The coordinated action of six muscles controls eyeball movements. To test the function of each muscle and the cranial nerve (CN) that innervates it, ask the patient to look in the direction controlled by that muscle. The six directions you can test make up the cardinal fields of gaze. The patient's inability to turn the eye in the designated direction indicates muscle weakness or paralysis.
SR — superior rectus (CN III)
IR — inferior rectus (CN III)
MR — medial rectus (CN III)
LR — lateral rectus (CN VI)
IO — inferior oblique (CN III)
SO — superior oblique (CN IV)
PHYSICAL
ASSESSMENT:
Take the patient's vital signs.
Check the patient's neurologic status. Evaluate his level of consciousness, pupil size and response to light, and motor and sensory function.
Find out if the patient can correct diplopia by tilting his head. If so, ask him to show you. (If the patient has a fourth nerve lesion, tilting of the head toward the opposite shoulder causes compensatory tilting of the unaffected eye. If he has incomplete sixth nerve palsy, tilting of the head toward the side of the paralyzed muscle may relax the affected lateral rectus muscle.)
Observe the patient for ocular deviation, ptosis, proptosis, lid edema, and conjunctival injection.
Determine whether the patient has monocular or binocular diplopia by asking him to occlude one eye. If he still sees double, he has monocular diplopia.
Test visual acuity and extraocular muscles.
Take the patient's vital signs.
Check the patient's neurologic status. Evaluate his level of consciousness, pupil size and response to light, and motor and sensory function.
Find out if the patient can correct diplopia by tilting his head. If so, ask him to show you. (If the patient has a fourth nerve lesion, tilting of the head toward the opposite shoulder causes compensatory tilting of the unaffected eye. If he has incomplete sixth nerve palsy, tilting of the head toward the side of the paralyzed muscle may relax the affected lateral rectus muscle.)
Observe the patient for ocular deviation, ptosis, proptosis, lid edema, and conjunctival injection.
Determine whether the patient has monocular or binocular diplopia by asking him to occlude one eye. If he still sees double, he has monocular diplopia.
Test visual acuity and extraocular muscles.
SPECIAL
CONSIDERATIONS:
Provide a safe environment. If the patient has severe diplopia, remove sharp obstacles and assist with ambulation. Also, institute seizure precautions, if indicated.
Provide a safe environment. If the patient has severe diplopia, remove sharp obstacles and assist with ambulation. Also, institute seizure precautions, if indicated.
PEDIATRIC
POINTERS:
Strabismus, which can be congenital or acquired at an early age, produces diplopia; however, in young children, the brain rapidly compensates for double vision by suppressing one image, so diplopia is a rare complaint.
School-age children who complain of double vision require a careful examination to rule out serious disorders such as brain tumor.
Strabismus, which can be congenital or acquired at an early age, produces diplopia; however, in young children, the brain rapidly compensates for double vision by suppressing one image, so diplopia is a rare complaint.
School-age children who complain of double vision require a careful examination to rule out serious disorders such as brain tumor.
PATIENT
COUNSELING:
Instruct the patient on what to expect from diagnostic testing. If appropriate, refer him to an ophthalmologist for further evaluation and treatment.
Instruct the patient on what to expect from diagnostic testing. If appropriate, refer him to an ophthalmologist for further evaluation and treatment.
Bibliography:
1. Rapid Assessment, A
Flowchart Guide to Evaluating Signs & Symptoms, Lippincott
Williams & Wilkins, 2004.
2. Professional Guide to
Signs and symptoms, Edition V, Lippincott
Williams & Wilkins, 2007.
3. Guide to common
symptoms, Edition V, McGraw - Hill, 2002.
Dorin,
Merticaru (2010)