Visual fields are examined using static or kinetic perimetry. The procedure is
performed separately for each eye, and measures the combined function of the
retina, the optic nerve, and the intracranial visual pathway. It is used
clinically to detect or monitor field loss due to disease at any of these
locations. Visual fields may be determined by several methods including a
tangent screen, Goldmann perimeter, and computerized automated perimeters.  
  
 **Visual field examinations will be considered medically necessary under the
following conditions:**

  1. Disorder of the eyelids potentially affecting the visual field.
  2. A documented diagnosis of glaucoma.

Stabilization or progression of glaucoma can be monitored by a visual field
examination, or by such services as scanning computerized ophthalmic
diagnostic imaging. This evaluation must be performed at regular intervals to
determine that the prescribed management is adequately controlling progression
of disease to the degree possible. The frequency of such examinations is
dependent on clinical judgment as well as the variability of intraocular
pressure measurements (e.g., progressive increases despite treatment indicate
a worsening condition), the appearance of new hemorrhages, and progressive
cupping of the optic nerve.

  3. A diagnosis of glaucoma is suspected with supporting evidence documented.

A suspected diagnosis of glaucoma is evidenced by an increase in intraocular
pressure over time, intraocular pressures of 22 mm Hg or more, asymmetric
intraocular measurements of greater than 2 mm Hg between the two eyes, or
optic nerves suspicious for glaucoma, which may be manifested as asymmetrical
cupping, a change in the cup-to-disc ratio over time, disc hemorrhage, or an
absent, thinned, or notched neural rim. Additional possible indicators of
glaucoma suspicion are fallout of the retinal nerve fiber layer, optic atrophy
(pallor of the optic nerve), corneal endothelial pigment deposits
(Krukenburg's Spindle), dense pigmentation of the trabecular meshwork as
evidenced by gonioscopy, pseudoexfoliation of the lens, or dense exfoliative
deposits on the trabecular meshwork as evidenced by gonioscopy.

  4. A documented disorder of the optic nerve, the neurologic visual pathway, or retina.

Patients with a previously diagnosed retinal detachment do not need a
pretreatment visual field examination. Additionally, patients with an
established diagnosed cataract do not need a follow-up visual field unless
other presenting symptomatology is documented. In patients who are about to
undergo cataract extraction, who do not have glaucoma and are not glaucoma
suspects, a visual field would not be indicated.

  5. A recent intracranial hemorrhage, an intracranial mass, or a recent measurement of increased intracranial pressure with or without visual symptomatology.

  6. A recently documented occlusion and/or stenosis of cerebral and precerebral arteries, a recently diagnosed transient cerebral ischemia, or giant cell arteritis.

  7. A history of a cerebral aneurysm, pituitary tumor, occipital tumor, or other condition potentially affecting the visual fields.

  8. A visual field defect demonstrated by gross visual field testing (e.g., confrontation testing).

  9. An initial workup for buphthalmos, congenital anomalies of the posterior segment, or congenital ptosis.

  10. A disorder of the orbit, potentially affecting the visual field (e.g., orbital tumor, thyroid disease, etc.).

  11. A significant eye injury.

  12. Unexplained visual loss which may be described as "trouble seeing or vision going in and out."

  13. A pale or swollen optic nerve documented by a recent examination.

  14. New functional limitations which may be due to visual field loss (e.g., reports by family that patient is running into things).

  15. Medication treatment (e.g., hydroxychloroquine) which has a high risk of potentially affecting the visual system.

  16. Initial evaluation for macular degeneration related to central vision loss or has experienced such loss resulting in vision measured at or below 20/70.

**Limitations**  
Gross visual field testing (e.g., confrontation testing) is a part of general
ophthalmological services and should not be reported separately.  
  
Frequency of examinations for a diagnosis of macular degeneration or an
experienced central vision loss (or to evaluate the results of a surgical
intervention or for the possible need for surgical intervention) is dictated
by stage of disease or degree of risk factors, just as with glaucoma
evaluation.  
  
Claims submitted for visual field examinations performed at unusually frequent
intervals may be reviewed to verify that the services were medically
reasonable and necessary.