Convergence insufficiency
| Convergence Insufficiency | |
|---|---|
| Classification and external resources | |
| Specialty | ophthalmology, optometry |
| ICD-10 | H51.1 |
| ICD-9-CM | 378.83 |
| eMedicine | oph/553 |
| MeSH | D015835 |
Convergence insufficiency or convergence disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence.
The symptoms and signs associated with convergence insufficiency are related to prolonged, visually demanding, near-centered tasks. They may include, but are not limited to, diplopia (double vision), asthenopia (eye strain), transient blurred vision, difficulty sustaining near-visual function, abnormal fatigue, headache, and abnormal postural adaptation, among others. In some cases, difficulty with making eye contact have been noted as a complaint amongst sufferers. Note that some Internet resources confuse convergence and divergence dysfunction, reversing them.
Among fifth and sixth grade children convergence insufficiency is 13%. In studies that used standardized definitions of Convergence insufficiency, investigators have reported a prevalence of 4.2% to 6% in school and clinic settings. The standard definition of Convergence insufficiency is exophoria greater at near than at distance, a receded near point of convergence, and reduced convergence amplitudes at near.
Diagnosis of convergence insufficiency is made by an eye care professional skilled in binocular vision dysfunctions to rule out any organic disease. Convergence insufficiency characterized by one or more of the following diagnostic findings: Patient symptoms, High exophoria at near, reduced accommodative convergence/accommodation ratio, receded near point of convergence, low fusional vergence ranges and/or facility. Some patients with convergence insufficiency have concurrent accommodative insufficiency—accommodative amplitudes should therefore also be measured in symptomatic patients.
Convergence insufficiency may be treated with convergence exercises prescribed by an eyecare specialist trained in orthoptics or binocular vision anomalies. Some cases of convergence insufficiency are successfully managed by prescription of eyeglasses, sometimes with therapeutic prisms.
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Wikipedia