Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What condition might a fixation or Ten-diopter base out test reveal in a patient suspected of malingering?

1. Convergence insufficiency

2. True vision loss in the affected eye

3. Hypertropia

4. Binocular diplopia

The correct answer is: True vision loss in the affected eye

In the context of diagnosing malingering, a fixation or Ten-diopter base out test is used to assess the functional vision of a patient who may be exaggerating or feigning visual loss. The primary purpose of this test is to differentiate between true vision loss and a non-organic cause of visual disturbance. When a patient shows a reduction in visual acuity during standard testing but demonstrates normal vision when subjected to the specific conditions of the Ten-diopter base out test, it suggests that the patient may not be experiencing true vision loss. In cases of true vision loss, the visual acuity would not improve under these conditions. Malingering can often be suspected when a discrepancy exists between a patient's reported symptoms and the results of objective testing. A baseline improvement in visual function when tested in a specific manner indicates that the patient's visual capabilities are intact, but they may be intentionally misrepresenting their condition. This perspective helps delineate between genuine visual impairments, like convergence insufficiency, hypertropia, or binocular diplopia, which would not solely reveal as symptoms of malingering when tested under these conditions. Therefore, the test helps in identifying whether the patient's reported visual problems stem from true loss or from other non-organic factors.