Partially Accommodative ET Characteristics

Summary

In this video, Polina discusses the characteristics of partially accommodative exotropia (ET), focusing on its association with hypermetropia. She explains how hypermetropia partially corrects the deviation, but not fully, as other anatomical and kinetic factors contribute. Polina distinguishes between patients with constant versus intermittent deviations, the potential for binocular single vision (BSV), and the classification of convergence excess patterns. The video concludes with insights into patient management, noting that patients with constant ET and convergence excess may not respond to bifocal treatment but can still have potential for BSV if the deviation was intermittent or occurred later in life.

Takeaways

• 😀 A partially accommodative exotropia (ET) is a condition where hypermetropia contributes to the deviation but does not fully correct it.
• 😀 In cases of partially accommodative ET, correction of hypermetropia may reduce the size of the deviation, but not completely eliminate it.
• 😀 Hypermetropia is one of the contributing factors to exotropia, but other anatomical and static factors also play a role in the deviation.
• 😀 Patients with a history of intermittent exotropia may develop a partially accommodative component over time, leading to a constant deviation.
• 😀 Correcting hypermetropia in patients with a partially accommodative ET might only partially improve the condition, especially if the deviation has become constant.
• 😀 Patients who previously had intermittent exotropia are more likely to have good potential for binocular single vision (BSV) after correction.
• 😀 Children with a constant exotropia and convergence excess may show a smaller deviation with glasses on, but larger at near distance.
• 😀 Patients with convergence excess patterns should not be classified as having a non-refractive accommodative exotropia unless the deviation was intermittent.
• 😀 A constant deviation, even with glasses, should still be considered a partially accommodative exotropia, not a convergence excess of accommodative ET.
• 😀 Constant deviation in patients with partial accommodative ET is often associated with amblyopia and absence of binocular functions, though some may have potential for BSV depending on the timing and nature of the deviation.

Q & A

What is partially accommodative esotropia (ET)?

Partially accommodative esotropia is a type of strabismus where the eye deviation is partially corrected by accommodating lenses, such as glasses. However, full correction is not possible due to other contributing factors beyond hypermetropia.

How does hypermetropia contribute to esotropia?

Hypermetropia, or farsightedness, contributes to esotropia by causing a deviation in the eyes that can be partially corrected with corrective lenses. However, hypermetropia is not the sole cause of the deviation—other anatomical and static factors also play a role.

What distinguishes partially accommodative ET from fully accommodative ET?

Partially accommodative ET can only partially correct the deviation with corrective lenses, while fully accommodative ET is completely corrected with such lenses. In partially accommodative ET, the deviation remains despite correction due to additional factors.

What is the typical history of patients with partially accommodative esotropia?

Patients with partially accommodative esotropia often have a history of intermittent esotropia that became more constant over time. In some cases, the condition began as a convergence excess and gradually developed an accommodative component.

What is the significance of convergence excess in partially accommodative ET?

Convergence excess is a condition where the eye deviation is larger at near distances than at far distances. In partially accommodative ET, some patients may show a convergence excess pattern, but the key distinction is that the deviation remains constant even with corrective lenses.

How does the presence of a convergence excess pattern affect diagnosis?

The convergence excess pattern in partially accommodative ET can cause confusion, but the patient should still be classified as having partially accommodative ET. A convergence excess pattern does not imply the patient has convergence excess esotropia, which is typically intermittent.

Do patients with partially accommodative ET respond to bifocals?

No, patients with partially accommodative ET do not respond to bifocals because their deviation cannot be fully corrected with lenses. Bifocals are typically effective for intermittent deviations, but not for constant ones like in partially accommodative ET.

What is the potential for binocular single vision (BSV) in patients with partially accommodative ET?

The potential for BSV in patients with partially accommodative ET depends on the patient's history. Those with a history of intermittent esotropia or a later onset of the condition may have better potential for BSV compared to those with a constant deviation from early childhood.

How do children with constant deviations in esotropia typically present in clinical settings?

Children with constant deviations usually present with amblyopia and lack binocular function. This is because the constant deviation often leads to suppression of one eye to avoid double vision.

What are the main factors contributing to the classification of esotropia as partially accommodative ET?

Esotropia is classified as partially accommodative ET when the deviation can only be partially corrected by accommodative lenses (e.g., glasses), and the condition remains constant despite full correction of refractive errors. It is also important to distinguish this from convergence excess and non-refractive accommodative ET.