Hypertropia
Hypertropia Causes
Hypertropia may be a congenital or acquired condition. Misalignment is commonly a result of an imbalance in extra-ocular muscle function. The inferior rectus, the superior rectus, the superior oblique, and the inferior oblique are the muscles responsible for vertical movement of the eyes. In congenital cases, the abnormality may be due to an aberrant development of the muscle structure, such as muscle atrophy/hypertrophy or the absence and incorrect placement of the muscle. Common identified causes include: inferior oblique overaction, superior oblique palsy or congenital fourth nerve palsy, Duane's retraction syndrome, Brown's syndrome, double elevator palsy, Graves disease, or surgical trauma to the vertical muscles. A sudden onset of hypertropia in elderly or middle aged adults is attributed to the compression of the trochlear nerve and mass effects from a tumor. It may also be a result of an infraction of the blood vessels that supply the nerve due to atherosclerosis or diabetes.
Hypertropia Definition
Hypertropia is characterized by the misalignment of the eyes, in which the visual axis of one eye is higher than the other. It is similar to hypotropia, wherein focus of the eye with the visual axis is lower than the fellow fixating eye.
Hypertropia Symptoms and Signs
The vertical miscoordination of the eyes may cause strabismic amblyopia due to the suppression of the deviating eye. A cosmetic defect is often evident at an early age. Face turn is also affected, dependent on the presence of binocular vision in a specific gaze. Diplopia or double vision may develop in adults. A cyclotorsional deviation of the eyes (or a rotation around the visual axis) is also common.
Hypertropia Treatment
Treatment for hypertropia may include prescription of eyeglasses to correct the refractive errors. Prism therapy, if tolerated, may also aid in managing diplopia. Patching is used particularly in treating amblyopia in kids and diplopia in adults. Botulinum toxin botox injection and surgical correction are also recommended.