Baltimore Eye Doctor on “Seeing Two of Everything”

Baltimore Washington Eye Center, Maryland

Tuesday, October 16, 2012

Baltimore Eye Doctor on “Seeing Two of Everything”

Baltimore eye doctor Arturo Betancourt, M.D. relayed a question about “seeing two” or diplopia and shared information about double vision. "Doctor, why am I seeing two of everything?" This condition is known as diplopia or double vision.  It should not be mistaken with blurred or fuzzy vision, a far more common occurrence. Diplopia results from an acquired misalignment of the eyes that causes an image to fall on non corresponding points of the retina.  I will discuss some of the most common types of acquired, adult diplopias as well as their etiology, in this blog. This is an overview and does not cover all reasons for diplopia, just the most common ones.

We will ask you a series of questions prior to starting our evaluation.
  • Do you have any medical problems, hypertension, diabetes or a neurological condition?
  • Have you suffered any trauma, or emotional or physical stress?
  • Is the deviation constant or intermittent?
  • Is the deviation present for distance, near or both?
  • Is it unilateral or alternating?
  • Is it present only when you are tired or fatigued? 
Diplopia can be monocular, arising from one eye, or binocular, due to ocular misalignment.  The most common reasons for monocular diplopia are an uncorrected refractive error or something blocking the path of light onto the retina. Examples of these would be corneal scars-secondary to trauma or infections, different types of cataracts and opacities in the vitreous cavity. Monocular diplopia does not disappear when the affected eye is covered. In binocular diplopia, the symptoms are only present with both eyes open, and disappear, when one eye is covered.  An easy way to determine if the cause is refractive is to use a pinhole.  The pinhole focuses light onto the retina, partially correcting a refractive error.  With the correction of the underlying problem, the diplopia will be resolved.

Binocular diplopia occurs when the same image falls on different points of the retina. The most common types are an abducens or sixth cranial nerve palsy and a superior oblique or fourth cranial nerve palsy.  The most common reasons for the occurrence of these two palsies in adults is micro vascular disease:  the main culprits being, hypertension and diabetes.  The damage occurs due to decreased circulation to the part of the brain responsible for the function of this muscle.

In a sixth nerve palsy or abducens palsy, the muscle that pulls the eye out from the horizontal is affected.  This causes the opposite muscle, the medial rectus, which pulls the eye towards the nose, to work unopposed.  This will cause the patient to see two horizontally displaced images.  If he closes one eye, either affected or unaffected eye, the diplopia will disappear.  It will also disappear if the patient moves his head to look at an object with the unaffected eye pointing away from the nose. Most of these palsies resolve over a matter of several weeks or months with little to no residual damage.  During that time the patient might be comfortable patching the eye with the poorer vision.  In an adult this will not result in any type of visual damage to either eye.  Unlike a very young child, in which occlusion might cause amblyopia or a lazy eye.  A palsy is not a lazy eye, but in a child, if untreated could result in one.

The other most common type of acquired adult diplopia is the one associated with the fourth cranial nerve or superior oblique.  The patient will experience a skew or slanted diplopia.  The objects will appear displaced both vertically and at an angle. They will not be perfectly in a vertical plane.  If the patient is looking with the unaffected eye, the affected eye will be pointed upwards.  If they are using the affected eye, the unaffected eye, will be pointing downwards. The patient might notice improvement of the diplopia if they tilt their head toward the shoulder opposite to the affected eye.  Again the treatment might be patching, and as with the sixth nerve palsy, resolution occurs in a matter of weeks or months.

The diagnostic work up for these two palsies would involve, blood pressure measurement, fasting blood sugar to rule out diabetes, and on rare occasions, mainly if trauma or another neurological problem are suspected, CT, MRI or MRA.  Both usually resolve within a matter of weeks or months and do so fully.  Sometimes if the patient is tired he might notice a slight amount of diplopia.  But this is usually transient. We have discussed some of the most common types of acquired, adult diplopia.  This discussion is not comprehensive and really just addresses some of the most common types.

Guest Blogger: Arturo E Betancourt M.D., F.A.C.S. with the Baltimore Washington Eye Center

If you or someone you know suffers from diplopia or double vision they are encouraged to schedule an eye examination at Baltimore Washington Eye Center by calling 800-495-3937, visiting Baltimore Washington Eye Center or, so that we can help identify the possible causes and recommend an appropriate treatment plan.

Baltimore Washington Eye Center is a leading eye care practice serving the greater Baltimore and Washington, D.C. area staffed by a team of Ophthalmologists, Optometrists, Opticians, technical and administrative staff who provide eye examinations for adults and children, diagnosis and treatment of cataracts including cataract surgery and intraocular lens implants (IOL), laser vision correction such as LASIK, diagnosis and treatment of cornea disease, care for diseases of the retina including diabetes and age related macular degeneration (AMD) and diagnosis and treatment of glaucoma as well as contact lenses, eyeglasses, eyewear  and optical services. Baltimore Washington Eye Center is conveniently located for patients from Arbutus, Carney, Clarksville, Columbia, Dundalk, Edgemere, Essex, Ellicott City, Ferndale, Glen Burnie, Kenwood, Laurel, Linthicum, Lutherville, Millersville, Odenton Owings Mills, Reisterstown, Towson, Parkville, Randallstown, Rivera Beach, Pasadena, Severna Park, South Gate and Woodlawn Maryland.