obsolete alternating exotropia with V pattern

Alternating Exotropia with V Pattern: An Obsolete Condition

Alternating exotropia with V pattern, also known as V-pattern exotropia, is a type of strabismus characterized by an alternating pattern of exotropia (outward deviation of the eyes) and esotropia (inward deviation of the eyes), with a greater exotropia in upgaze than in downgaze. This condition was once considered a distinct entity, but it is now largely obsolete due to advances in understanding and classification of strabismus.

Historical Context

In the past, alternating exotropia with V pattern was recognized as a specific type of strabismus, often associated with inferior oblique muscle overaction. However, with the development of more sophisticated diagnostic techniques and a deeper understanding of strabismus mechanisms, this condition has been subsumed under broader categories.

Current Understanding

Today, alternating exotropia with V pattern is no longer considered a distinct diagnosis. Instead, it is viewed as a manifestation of underlying oblique muscle dysfunction, specifically inferior or superior oblique muscle overaction. This understanding has led to more targeted and effective treatment approaches, such as muscle surgery or botulinum toxin injections.

Key Points

• Alternating exotropia with V pattern was once considered a distinct type of strabismus.
• It is now recognized as a manifestation of underlying oblique muscle dysfunction.
• Inferior or superior oblique muscle overaction are common causes of this condition.
• Treatment approaches have evolved to target the underlying muscle dysfunction.

References:

[1] Rutstein, R. P. (1995). Infantile exotropia: A review of 50 cases. [Context result 6]

[2] Caldeira, J. A. (2013). Some clinical characteristics of V-pattern exotropia and surgical outcome after bilateral recession of the inferior oblique muscle. Journal of AAPOS, 17(5), 588-593. [Context result 13]

[3] Oblique muscle dysfunction is a common cause of strabismus, including alternating exotropia with V pattern. [Context results 11 and 14]

Signs and Symptoms of Alternating Exotropia with V Pattern

Alternating exotropia with a V pattern is a type of strabismus where one eye deviates outward, and the deviation alternates between the two eyes. The V pattern refers to the increased deviation in upgaze compared to downgaze.

Common Signs and Symptoms:

• Outward Eye Deviation: One eye deviates outward, which alternates between the left and right eyes.
• Asthenopic symptoms: Patients may experience eyestrain, blurring, headache, and difficulty with prolonged periods of reading.
• Transient Diplopia: Horizontal diplopia (double vision) is a common symptom, especially when the deviation is more pronounced.
• Micropsia: Some patients may experience micropsia, which is a perception that objects appear smaller than they actually are.

Other Symptoms:

• Gradual loss of fusional control, leading to an increase in the frequency and duration of the manifest phase.
• Ptosis (drooping eyelid) may be unilateral or bilateral, although it's not always present.
• The deviation may be more pronounced in certain directions, such as upgaze or downgaze.

Important Considerations:

• Recognizing the symptoms of alternating exotropia with a V pattern is crucial for timely diagnosis and treatment.
• Early detection and intervention can help prevent long-term complications and improve visual outcomes.

References:

[1] Some patients may notice symptoms like eyestrain, blurring, headache and difficulty with prolonged periods of reading. However, soon the children become ... [1] [5] Symptoms Intermittent Exotropia. 1.Transient Diplopia 2.Asthenopic symptoms like eyestrain, blurring, headache and difficulty with prolonged periods of reading.[5] [11] The signs and symptoms of exotropia include: Eyes turned outward some or all of the time. Squinting. Eye strain. Headaches. Double vision (diplopia ... [11] [14] Outward Eye Deviation. The hallmark symptom of alternating exotropia is the outward deviation of one eye, which alternates between the left and right eyes.[14] [15] Symptoms may be mild or severe. If suppression of the deviating eye occurs, the patient can have diminished binocular vision and ... [15]

Based on the provided context, it appears that there are several diagnostic tests used to identify and diagnose alternating exotropia with a V-pattern.

• Alternate Cover Test (ACT): This test is used to measure the deviation of the eyes in different gaze positions. In patients with V-pattern exotropia, the deviation is more pronounced in downgaze than in upgaze [2]. The ACT should be performed at 6 meters to eliminate the near reflex and ensure accurate measurements.
• Prism and Alternate Cover Test (PACT): This test involves using prisms to measure the deviation of the eyes. In V-pattern exotropia, a significant difference in horizontal deviation between upgaze and downgaze is expected, with a minimum difference of 15 prism diopters [2].
• Patch Test: The patch test is used to control tonic fusional convergence and differentiate pseudo-divergence excess from true divergence excess. This test can be useful in diagnosing alternating exotropia with a V-pattern [10].

It's also worth noting that the diagnosis of an A- or V-pattern must be made by measuring with the prism and alternate cover test 25−30°above and below the midline, testing should be done at 6 m to eliminate the near reflex [8].

The differential diagnosis for obsolete alternating exotropia with V-pattern involves considering various conditions that may present similarly to this condition. Based on the search results, here are some possible differentials:

• Intermittent Exotropia: This is a common type of exodeviation that usually begins in early childhood and involves periods where the eyes are aligned [5]. It's essential to rule out intermittent exotropia as it can present with similar symptoms.
• Sensory Exotropia: This condition occurs due to congenital monocular media opacity or other causes of congenital monocular vision loss, which can lead to alternating exotropia with a V-pattern [6].
• V-Pattern Esotropia: Although this is an esotropic condition, it's essential to consider it in the differential diagnosis as it can present with a similar V-pattern configuration.
• Convergence Excess Esotropia (CEET): This is a rare complication of LDA-induced esotropia that can present with a V-pattern [9]. It's crucial to rule out CEET, especially if there's a history of LDA use.

When differentiating between these conditions, it's essential to consider the following factors:

• Age of onset: Obsolete alternating exotropia typically presents in early childhood, whereas sensory exotropia may present later in life.
• Type of deviation: Intermittent exotropia and V-pattern esotropia are characterized by horizontal deviations, while sensory exotropia can involve vertical deviations as well.
• Presence of other symptoms: Convergence excess esotropia (CEET) is often associated with hypoaccommodation following LDA use.

A thorough clinical evaluation, including a detailed history and examination, is necessary to accurately diagnose obsolete alternating exotropia with V-pattern. Consultation with an ophthalmologist or strabismologist may be required for further guidance.

References:

[5] Intermittent Exotropia: A common type of exodeviation that usually begins in early childhood. [6] Sensory Exotropia: A condition occurring due to congenital monocular media opacity or other causes of congenital monocular vision loss. [9] Convergence Excess Esotropia (CEET): A rare complication of LDA-induced esotropia that can present with a V-pattern.