Accommodative Component in Esotropia
An accommodative component (or AC) in esotropia is a type of extraocular misalignment of the eyes that results from an abnormal transmission of the force of accommodation. This type of misalignment occurs when the muscle power needed to correct for the refractive (focusing) error of the eye is insufficient.
Symptoms of Accommodative Component Esotropia
The most common symptom associated with an accommodative component in esotropia is an inward crossing of the eyes (esotropia) when focusing on near/close objects. The eyes may also become crossed at distance. Patients may also experience headaches, eyestrain and blurred vision. Patients may also have convergence insufficiency, in which the eyes do not align properly when viewing near objects.
Causes of Accommodative Component Esotropia
The primary cause of accommodative component esotropia is an imbalance between the two main visual abilities (accommodation and convergence) that will not correct with spectacles. In rare cases, accommodative component esotropia can be caused by an underlying medical condition such as thyroid eye disease or diabetes.
Treatment of Accommodative Component Esotropia
The primary treatment of accommodative component esotropia is corrective eyeglasses, general vision therapy exercises that may help to improve vision, or other treatments to strengthen the eye focusing muscles. Patients may also benefit from optical prisms, or surgical correction.
Optical Prisms for Accommodative Component Esotropia
Optical prisms can be used to help compensate for the extraocular misalignment associated with accommodative component esotropia. Prisms can temporarily help to reduce the inward-crossing of the eyes (esotropia) by decreasing the amount of force of accommodation exerted on the eyes.
General Vision Therapy Exercises
General vision therapy exercises can help to improve vision and strengthen the eye focusing muscles. The following exercises are commonly used to treat accommodative component esotropia:
- Near point of convergence exercises, which involve focusing on an object that is close to the eyes.
- Pencil push-ups, which involve holding a pencil in the peripheral vision and slowly pushing it inwards.
- Focusing exercises, which involve repeatedly changing focus from far to near.
- Accommodation relaxation exercises, which involve gazing at distant objects while blocking intervening objects.
Surgical Treatment for Accommodative Component Esotropia
In cases where the other treatments do not improve the extraocular misalignment, surgery may be recommended to correct the accommodative component esotropia. Surgery to correct esotropia involves weakening the eye muscle(s) that is contributing to the inward-crossing of the eyes.