DEFINITION:
A sensorimotor anomaly of the binocular vision system characterized by the non-fixating eye turning upward under conditions of dissociation.
SIGNS AND SYMPTOMS:
The signs and symptoms associated with dissociated vertical deviation may include, but are not limited to, the following:
- abnormal postural adaptation/abnormal working distance (ICD: R29.3)
- eye turn, deviation (ICD: H50.9)/diplopia (ICD: H53.2)
- inaccurate/inconsistent depth judgment
- spatial disorientation
DIAGNOSTIC FACTORS:
Dissociated vertical deviation is characterized by the diagnostic finding that either eye turns upward when covered.
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:
- the severity of symptoms and diagnostic factors, including onset and duration of the problem
- the complications of associated visual conditions
- implications of patient’s general health, cognitive development, physical development, and effects of medications taken
- etiological factors
- extent of visual demands placed upon the individual
- patient compliance and involvement in the prescribed therapy regimen
- type, scope, and results of prior interventions
PRESCRIBED TREATMENT REGIMEN:
The goal of the prescribed treatment regimen is to address the diagnostic factors and alleviate the presenting signs and symptoms of the diagnosed condition. Some cases are successfully managed by the prescription of therapeutic lenses and/or prisms. Most dissociated vertical deviation cases require optometric vision therapy, which incorporates the prescription of specific treatments in order to:
- develop adequate fusional vergence ranges and stability in all positions of gaze at distance and near
- enhance accommodative/convergence relationships
- enhance depth judgments and/or stereopsis
- integrate binocular function with information processing
- enhance fusional vergence facility and flexibility
- integrate binocular skills with accurate motor responses
- integrate binocular skills with other sensory skills (vestibular, kinesthetic, tactile, and auditory)
- increase visual stamina/integrate newly established skills with information processing
DURATION OF TREATMENT:
The following treatment ranges are provided as a guide. Treatment duration will depend upon the particular patient’s condition and associated factors. 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.
- Full treatment requires resolution of associated visual conditions.
- The most commonly encountered dissociated vertical deviation evident in a non-strabismic case usually requires 40 hours of office therapy.
- The most commonly encountered dissociated vertical deviation evident in a strabismic case usually requires 60 hours of office therapy.
- Dissociated vertical deviation 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.