Strabismic Amblyopia

DEFINITION:

An amblyopia present in the deviating eye of a strabismic individual characterized by a decrease in visual acuity and performance of the visual system not attributable to obvious structural or pathological anomalies, and not correctable with a refractive prescription.

 

SIGNS AND SYMPTOMS:

The signs and symptoms associated with strabismic amblyopia may include, but are not limited to, the following:

1. eye turn, deviation (ICD: 9)
2. reduced monocular vision
3. inaccurate/inconsistent depth judgment
4. inaccurate eye-hand coordination
5. avoids eye contact
6. avoidance of visually demanding tasks
7. abnormal postural adaptation/abnormal working distance (ICD: 3)
8. spatial disorientation
9. incoordination/clumsiness (ICD: 8)

 

DIAGNOSTIC FACTORS:

Strabismic amblyopia is characterized by one or more of the following diagnostic findings:

1. reduced monocular acuity with refractive error compensated
2. strabismus (ICD:H50.9)
3. eccentric/unsteady foveal fixation
4. poor monocular performance skills such as oculomotor skills, spatial judgments, accommodation, sensitivity to crowding

 

THERAPEUTIC MANAGEMENT CONSIDERATIONS:

The doctor of optometry determines appropriate diagnostic and therapeutic modalities, and frequency of evaluation and follow-up, based on the urgency and nature of the patient’s conditions and unique needs. Vision disorders that are not totally cured through vision therapy may still be ameliorated with significant improvement in visual function and quality of life. The management of the case and duration of treatment would be affected by:

1. the severity of symptoms and diagnostic factors, including onset and duration of the problem
2. the complications of associated visual conditions
3. implications of patient’s general health, cognitive development, physical development, and effects of medications taken
4. etiological factors
5. extent of visual demands placed upon the individual
6. patient compliance and involvement in the prescribed therapy regimen
7. type, scope, and results of prior interventions
8. occupational/avocational goals

 

PRESCRIBED TREATMENT REGIMEN:

The goal of the prescribed treatment regimen is to address the diagnostic factors and alleviate the presenting signs and symptoms associated with the diagnosed condition. Optometric vision therapy is required to achieve maximum improvement in patients with strabismic amblyopia. Optometric vision therapy usually incorporates the prescription of specific treatments in order to:

1. address retinal image quality
2. normalize fixation accuracy, ocular motor control, accommodation (accuracy, amplitude, and facility)
3. enhance Just Noticeable Difference (JND), spatial resolution, spatial judgments, and visual information processing
4. address asymmetry of performance

 

DURATION OF TREATMENT:

The following treatment ranges are provided as a guide. Treatment duration depends upon the particular patient’s condition and associated circumstances. When duration of treatment beyond these ranges is required, documentation of the medical necessity for additional treatment services may be warranted for third-party claims processing and review purposes.

1. Full treatment requires resolution of the
2. The most commonly encountered strabismic amblyopia case usually requires 60 hours of office therapy.
3. Strabismic amblyopia may require substantially more office therapy, if complicated by associated factors such as prior eye muscle surgery, cerebral vascular accident, head trauma, and/or systemic conditions.

 

FOLLOW-UP CARE:

At the conclusion of the active treatment regimen, periodic follow-up evaluation is required. Should signs, symptoms, or other diagnostic factors recur, further therapy may be medically necessary.

Therapeutic lenses may be prescribed during or at the conclusion of active vision therapy to assist in the maintenance of long-term stability.