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

1. Manifest angle of eye deviation
2. Deficient vergence abilities, reduced ranges of fusion with poor depth perception/stereopsis (368.33)
3. Diplopia (368.2)
4. Sensory adaptations (e.g. suppression 368.31; amblyopia 368.0; abnormal retinal correspondence 368..34)

NOTE: Additional testing may be appropriate as part of the differential diagnostic workup for strabismus to rule out other concurrent medical conditions and to differentiate associated visual conditions.

1. Management
   
   The doctor of optometry determines appropriate diagnostic and therapeutic modalities, and frequency of evaluation and follow-up, based upon the urgency and nature of the patient’s condition and unique needs. 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. Implications of patient’s general health and associated visual conditions
   3. Extent of visual demands placed upon the individual
   4. Patient compliance
   5. Prior interventions
       
2. Treatment
   
   A small percentage of cases are successfully managed by prescription of therapeutic lenses or prisms. However, most patients with strabismus require orthoptics/vision therapy. Optometric vision therapy usually incorporates the prescription of specific treatments in order to:
    
   1. Normalize ocular motor control
   2. Normalize spatial localization skills
   3. Normalize accommodative abilities
   4. Eliminate sensory adaptations
   5. Establish fusion response at all distances and in all fields of movement
   6. Normalize accommodative/convergence relationship
   7. Integrate oculomotor function with information processing
       

The following treatment ranges are provided as a guide for third party claims processing and review purposes. Treatment duration will depend 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.

1. The most commonly encountered intermittent exotropia usually requires 36 to 48 hours of office therapy.
2. The most commonly encountered constant exotropia usually requires 50 to 64 hours of office therapy.
3. Exotropia complicated by:
   1. associated visual anomalies (e.g. amblyopia, abnormal retinal correspondence) require additional office therapy.
   2. associated visual anomalies (e.g. cycloptropia, hypertropia) require additional office therapy.
   3. associated conditions such as stroke, head trauma, strabismus surgery require substantially more office therapy.

1. The most commonly encountered intermittent esotropia usually requires 40 to 52 hours of office therapy.
2. The most commonly encountered constant esotropia usually requires 60 to 75 hours of office therapy.
3. Esotropia complicated by:
   1. associated visual adaptations (e.g. suppression, amblyopia, abnormal retinal correspondence) require additional office therapy.
   2. associated visual anomalies (e.g. cyclotropia, hypertropia) require additional office therapy.
   3. associated conditions such as stroke, head trauma, strabismus surgery require substantially more office therapy.