Originally posted by tomz
Thank you, Dr. Doan.
Could you list some common symptoms of Exotropic and Esotropic?
Esotropia can be divided into two broad categories: congenital and acquired.
For congenital esotropia, this usually presents in babies less than 6 months of age. One eye will be seen as severely turned in. A congenital sixth nerve palsy will also result in the paretic eye to turn in.
For acquired esotropia, some causes can be: anisometropic (unequal refraction), media opacity (cataract, corneal clouding, tumor, etc..), refractive (significant myopia or hyperopia), accomodative esotropia, and acquired sixth nerve palsy.
Young children do not complain of double vision usually because they'll suppress one eye resulting in poor binocular fusion. All the esotropias will present with one or two eyes turned in, depending on the severity. In adults, you'll see esotropia commonly in diabetics and vasculopaths with sixth nerve palsies, and these patients complain about binocular, horizontal double vision. In a sixth nerve palsy, the patient cannot move the paretic eye in abduction (moving the eye out temporally).
There's also the Duane's syndrome that present as abduction and adduction deficits and may also present with esotropia. There may be fissure narrowing and globe retraction of the paretic eye on adduction (movement of eye towards the nose). Duane's is a sixth nerve nuclei abnormality with abnormal innervation of the lateral rectus by the third nerve (evidence is soft), hence we see fissure narrowing and globe retraction when both the medial and lateral rectus contract on adduction.
For exotropia, this may be due to refractive error, anisometropia, third nerve palsy, or divergence excess. In all these cases, the patient will have an eye that turns out away from the nose, and depending on the age and time of onset, may complain of double vision.
Exotropia can also be broken down in children and adults to be: basic divergence excess (exotropia is same at near and far), true divergence excess (exotropia is greater at far than near), pseudo-divergence excess (exotropia is greater at far than near until fusion is broken to remove any accommodative effort resulting in the extropia to be the same at near and far), and then accomodative insufficiency where the exotropia is greater at near and patients have trouble reading.
Keep in mind that Esoptropia and Exotropia can be also seen in several diseases: Grave's, myasthenia gravis, orbital tumors, diabeties, vascular diseases, pseudotumor, mitochondrial diseases, intracranial masses, increased ICP, etc... It's important to recognize these disease entities because missing the clues may result in death or severe morbidity.
As you can see, the symptoms of exotropia and esotropia will vary depending on it's cause. Thus, depending on the cause, the treatment may be as simple as prescribing corrective lenses, using prism, patching one eye, medical treatment, or surgical realignment of the extraocular muscles. There's always the option of doing nothing if the patient is not bothered and the cause is benign.
