Wednesday, June 12, 2024

Amblyopia

Practice Essentials

Amblyopia, or lazy eye, refers to a unilateral or bilateral decrease of vision, in one or both eyes, caused by abnormal vision development in childhood or infancy. It is a common vision problem in children and is the leading cause of decreased vision among children. Most vision loss is preventable or reversible with the right kind of intervention.

Signs and symptoms

The history should address the following:

Previous history of patching or eye drops

Past compliance with these therapies

Previous ocular surgery or disease

Family history of strabismus or other ocular problems

The physical examination should include the following:

Assessment of visual acuity

Testing for crowding phenomenon (difficulty in distinguishing optotypes that are close together)

Specific testing measures in preverbal children

Evaluation of contrast sensitivity

Neutral density filter testing

Assessment of binocular function

Detection of eccentric fixation

Cycloplegic refraction

Sensory testing

Motility examination

A full eye examination must be performed to rule out ocular pathology.

The most important causes of amblyopia are as follows
:

Anisometropia or refractive errors

Strabismus

Strabismic anisometropia

Visual deprivation

Organic lesions

See Clinical Presentation for more detail.

Diagnosis

Imaging studies that may be helpful when the ocular examination is normal and suspicion of an organic cause exists include the following:

CT

MRI

Fluorescein angiography (to assess the retina)

Other tests that may be helpful in diagnosis include the following:

Electrophysiologic studies (investigational; differences noted are controversial)

Spectral-domain optical coherence tomography (SD-OCT)

See Workup for more detail.

Management

First, rule out an organic cause and treat any obstacle to vision, such as cataract or ptosis, if clinically significant. Next, treat anisometropia and refractive errors. Then, initiate occlusion therapy (to force the use of the amblyopic eye) or penalization therapy.

Occlusion therapy

The following are general guidelines for occlusion therapy:

Patching may be full-time or part-time

Always consider lack of compliance in a child when visual acuity is not improving. Question patients regarding peeking

In addition to adhesive Band-Aid–type patches, consider the use of opaque contact lenses, occluders mounted on spectacles, and adhesive tape or Bangerter foils on glasses

Establishing whether the vision of the better eye has been degraded sufficiently with the chosen therapy

Other treatment

Additional treatment options include the following:

Atropine penalization therapy (also used for maintenance)

Optical blurring through contact lenses or elevated bifocal segments

Treatment of strabismus generally occurs last. The endpoint of strabismic amblyopia is freely alternating fixation with equal vision. Surgery generally is performed after this endpoint has been reached.

See Treatment and Medication for more detail.

RELATED ARTICLES
- Advertisment -

Most Popular