Question: How would you code a visual field defect arising from pituitary adenoma? Florida Subscriber Answer: In this case, pituitary adenoma is most likely the cause of the visual field defect. Therefore, you would code the tumor as the secondary diagnosis with the most appropriate code, such as D49.7 (Neoplasm of unspecified behavior of endocrine glands and other parts of nervous system).
For the visual field examination, you can use any of the following codes, depending on the case: Visual fields also allow you to bill the field defect as your diagnosis code. For example, pituitary adenomas often show a heteronymous field defect (H53.47, Heteronymous bilateral field defects). This diagnosis will work equally as well for the diagnosis, especially when the ophthalmologist finds the visual field before the endocrinologist finds the pituitary problem.