CLINICAL TYPES OF OCULAR DEVIATION

OCULAR DEVIATION can be defined as misalignment of the visual axis of the two eye.

Types of ocular deviation:

•Esodeviations

•Exodeviations

•Vertical Deviations

•Cyclodeviations

ESODEVIATIONS

Esophoria: It denotes the inward deviation of the globe only when the fusion reflex during binocular vision is interrupted.
Esotropia: It denotes the inward deviation of the globe that cannot be overcome by fusion reflex.

Esotropia can be further divided into

Comitant Esotropia: it is the manifest convergent deviation of the eye, in which the amount of deviation in the squinting eye remains constant is all directions of gaze and there is no associated limitation of ocular movements.
Infantile Esotropia: it is a manifest esodeviation with an onset between birth and 6 months of age.

Accommodative Esotropia: an esotropia caused by over convergence in response to increased accommodative effort or an abnormally high AC/A ratio.

Refractive accommodative- it refers to the type of esotropia that is caused mostly due to uncorrected hypermetropia, that varies in degree depending on the amount of accommodation exerted and it can be restored to orthoposition at all fixation distances and in all gaze positions by optical correction of the underlying hypermetropic refractive error.

Non- refractive accommodative- it is defined as an esotropia which is caused by a high AC/A ratio thus esotropia is significantly greater at near than distance fixation.
Mixed or partially accommodative- it is described as an esotropia which is caused partially due to accommodative factors like hypermetropia and partially due to some non-accommodative factors.
Non-Accommodative Esotropia: This type of esodeviation is not affected by the state of accommodation.
Acquired or Late onset non-accommodative Esotropia
Acute Comitant Esotropia- it is a sudden onset of a large angle comitant esotropia without any paralytic element and it is associated with diplopia.
Cyclic Esotropia
Stress-induced Esotropia
Esotropia in myopia
Esotropia due to spasm of near reflex
Secondary Esotropias: it a type of esotropia which develops due to poor visual function in one eye in childhood.
Consecutive Esotropias: in this type the eye become esotropic in an eye which was once exotopic.
Incomitant Esotropia
Paralytic Esotropias
Lateral rectus paralysis
Divergence paralysis
Mobius syndrome
A and V Pattern Esotropia
Special types of restrictive Esotropia
Duane’s retraction syndrome(with Esotropia)
Thyroid Myopathy
Medial orbital wall fracture
Strabismus fixsus
Excessively resected medial rectus muscle

EXODEVIATIONS:

Exophoria: A condition in which one or other eye deviates outwards only when the fusion reflex during binocular vision is interrupted.

Exotropia: A condition in which one or other eye deviates outwards, that cannot be overcome by fusion reflex.

Comitant exotropias: it is the manifest divergent deviation of the eye, in which the amount of deviation in the squinting eye remains constant is all directions of gaze and there is no associated limitation of ocular movements.
Primary exotropias- it is an idiopathic type of exodeviation in which the deviation is the essential feature.
Divergent excess type
Convergence insufficiency type
Basic exotropia
Pseudodivergence excess type
Secondary exotropias- it refers to unilateral exotropia that develops as a result of poor visual function in one eye.
Consecutive exotropia- it refers to occurrence of exotropia in an eye which was previously esotropic.

Incomitant exotropias
Paralytic exotropias
Isolated medial rectus paresis
Complete third nerve paralysis
Paralysis of convergence
A, V and X Pattern exotropias
Special types of restrictive exotropias
Duane’s retraction syndrome(with Exotropia)
Craniofacial anomalies with divergent orbit
Thyroid myopathy
Restriction due to trauma or excessive surgery

VERTICAL DEVIATIONS

Hyperphoria- the non-fixating eye is higher than fixating eye only when the fusion of the two eye is interrupted.
Hypertropia: the non-fixating eye is higher than fixating eye.

Hypotropia: the non-fixating eye is lower than fixating eye.

Comitant Hypertropia: it is the manifest vertical deviation of the eye, in which the amount of deviation in the squinting eye remains constant is all directions of gaze and there is no associated limitation of ocular movements.
Induced Hypertropia
End result of long- standing paralytic deviation
Incomitant Hypertropia
Apparent oblique muscle dysfunction
Inferior oblique overaction
Inferior oblique underaction
Superior oblique overaction
Superior oblique underaction
Paretic vertical deviations
Restrictive vertical deviations
Dissociated vertical deviation: they are characterized by hyperdeviation in one eye while the other eye is fixating, the non-fixing eye is also extorted and slightly abducted.
Monocular dissociated vertical deviations
Binocular or alternating dissociated vertical deviations

CYCLODEVIATIONS: refers to misalignment of the eyes around the anteroposterior axis of the eye.

A. Cyclophorias

Incyclophoria- the deviated eye is intorted that is rotated around its anteroposterior axis in a way that superior portion of the vertical meridian is torted nasally and the inferior portion of the vertical meridian is torted temporally.
Excyclophoria- the deviated eye is extorted that is rotated around its anteroposterior axis in a way that superior portion of the vertical meridian is torted temporally and the inferior portion of the vertical meridian is torted nasally.

B. Intermittent cyclotropias