Hypertropia

Hypertropia is a condition of misalignment of the eyes ( strabismus ), whereby the visual axis of one eye is higher than the fellow fixating eye.

Hypotropia is the similar condition, focus being on the eye with the visual axis lower than the fellow fixating eye.

Dissociated vertical deviation is a special type of hypertropia leading to slow upward drift of one or rarely both eyes, usually when the patient is inattentive.

Hypertropia may be either congenital or acquired, and misalignment is due to imbalance in extraocular muscle function.

Refractive errors such as hyperopia and anisometropia may be associated abnormalities found in patients with vertical strabismus.

strabismic amblyopia due to cerebral suppression of the deviating eye, particularly when onset occurs well before adolescence, while neural pathways are still highly plastic

impaired depth perception , especially in the same instances

diplopia or double vision, particularly when onset occurs after childhood, when corresponding neural pathways have been so fixed as to prevent the brain from suppressing the deviant image

cosmetic defect, most noticed by parents of a child so affected and in photographs

face turn, depending on presence of binocular vision in a particular gaze

cyclotropia , a cyclotorsional deviation of the eyes (rotation around the visual axis), particularly when the root cause is an oblique muscle paresis causing the hypertropia

Sudden onset hypertropia in a middle aged or elderly adult may be due to compression of the trochlear nerve and mass effect from a tumor, requiring urgent brain imaging using MRI to localise any space occupying lesion

Various surgical procedures have been described and should be offered after careful examination of eyes, including a detailed orthoptic examination focussing on the disturbances in ocular motility and visual status.

Correction of refractive errors by glasses

Prism therapy (if tolerated, to manage diplopia)

Vision Therapy

Patching (mainly to manage amblyopia in children and diplopia in adults)

Botulinum toxin injection

Surgical correction of the hypertropia is desired to achieve binocularity, manage diplopia and/or correct the cosmetic defect.

Specialty fellowship trained pediatric ophthalmologists and strabismus surgeons are best equipped to deal with these complex procedures.

Sudden onset hypertropia in a middle aged or elderly adult may be due to compression of the trochlear nerve and mass effect from a tumor, requiring urgent brain imaging using MRI to localise any space occupying lesion

It could also be due to infarction of blood vessels supplying the nerve, due to diabetes and atherosclerosis.

In other instances it may be due to an abnormality of neuromuscular transmission, i.e., Myasthenia Gravis.