Cataract is defined as an opacity or loss of optical clarity of the
crystalline lens. Cataract development follows a continuum extending from
minimal changes in the crystalline lens to the extreme stage of total opacity.
Cataracts may be due to a variety of causes. Age-related cataract (senile
cataract) is the most common type found in adults. Other types are pediatric
(both congenital and acquired), traumatic, toxic and secondary (meaning the
result of another disease process) cataract.  
  
Most cataracts are not visible to the naked eye until they become dense enough
(mature or hypermature) to cause blindness. However, a cataract at any stage
of development can be observed through a sufficiently dilated pupil using a
slit lamp biomicroscope. In settings where this instrument is unavailable
(e.g., skilled nursing facility), a direct ophthalmoscope can be used to
assess the degree to which the fundus reflectivity (red reflex) is impaired by
the ocular media. There is no scientifically proven medical (i.e., non-
surgical) treatment for cataracts.  
  
In general, cataract surgery is performed to alleviate compromise of visual
function attributable to lens opacity. There are uncommon situations when lens
extraction becomes medically necessary for anatomic rather than optical
reasons. These include lens induced angle closure (e.g., microspherophakia)
and lens subluxation (e.g., Marfan syndrome). In other situations, cataract
extraction might be medically indicated with relatively less opacity because
of intolerable optical imbalance. Most commonly, this would be due to
surgically induced anisometropia (a significant difference in refractive
errors between the eyes) or aniseikonia (a difference in magnification as a
result of prior lens extraction in the one eye). Some patients may elect lens
removal and replacement primarily for refractive benefits to reduce their
dependence on spectacles. Such elective procedures are not medically necessary
and are called "refractive lens exchanges" to distinguish them from medically
indicated cataract surgery. Finally, advanced cataracts may need to be removed
to properly visualize, treat, and monitor retinal disease, apart from the
patient's visual symptoms and potential.  
  
This policy statement defines the medical necessity for cataract and other
lens extraction in adults, and specifies the required documentation of the
preoperative evaluation necessary to justify the procedure.  
  
 **MEDICAL NECESSITY**  
Lens extraction is considered medically necessary and therefore covered by
Medicare when one (or more) of the following conditions or circumstances are
documented in the medical record (see Documentation Requirements in Article
A57196):

  1. Cataract causing symptomatic (i.e., causing the patient to seek medical attention) impairment of visual function not correctable with a tolerable change in glasses or contact lenses resulting in the patient's inability to function satisfactorily while performing Activities of Daily Life including, but not limited to reading, viewing television, driving, or meeting vocational or recreational needs.
  2. Concomitant intraocular disease (e.g., diabetic retinopathy or intraocular tumor) requiring monitoring or treatment that is prevented by the presence of cataract.
  3. Lens-induced disease threatening vision or ocular health (including, but not limited to, phacomorphic or phacolytic glaucoma).
  4. High probability of accelerating cataract development as a result of a concomitant or subsequent procedure (e.g., pars plana vitrectomy, iridocyclectomy, procedure for ocular trauma) and treatments such as external beam irradiation.
  5. Cataract interfering with the performance of vitreoretinal surgery.
  6. Intolerable anisometropia or aniseikonia uncorrectable with glasses or contact lenses that exists as a result of lens extraction in the first eye (despite satisfactorily corrected monocular visual acuity.

Any circumstances not listed may be considered based on the standard of care
and other factors related to medical necessity at redetermination.

Surgery is not deemed to be medically necessary purely on the basis of lens
opacity in the absence of one or more of the aforementioned justifications.

**Visual Acuity**  
The Snellen visual acuity chart is an excellent way of measuring distance
refractive error (e.g. myopia, hyperopia, astigmatism) in healthy eyes, and is
in wide clinical use. However, testing only with high contrast letters viewed
in dark room conditions will underestimate the functional impairments caused
by some cataracts in common real-life situations such as day or nighttime
glare conditions, poor contrast environments or reading, halos and starbursts
at night, and impaired optical quality causing monocular diplopia and
ghosting.

While a single arbitrary objective measure might be desirable a specific
Snellen visual acuity alone can neither rule in nor rule out the need for
surgery. Visual acuity should be considered in the context of the patient's
visual impairment and other ocular findings.

**Specialized Ophthalmic Testing**

For circumstances where the placement of an intraocular lens (IOL) is
anticipated, A-scan ultrasound testing or partial coherence interferometry,
keratometry (may be from corneal topography), and IOL calculations and
selection would be anticipated to be performed.

Additional ancillary testing as appropriate in the establishment or exclusion
of medical necessity. This should be directed by specific patient complaint or
symptom where possible.

Certain testing would **_not_** be anticipated to be required in a pre-
operative workup when performing routine cataract surgery. These include, but
are not limited to:

  1. B-Scan/Ultrasound of the Posterior Segment
  2. Glare Testing
  3. Brightness Acuity Testing
  4. Low-contrast visual acuity testing
  5. Contrast sensitivity testing 
  6. Potential vision testing 
  7. Formal visual fields 
  8. Fluorescein angiography 
  9. External photography 
  10. Corneal pachymetry/specular microscopy 
  11. Specialized color vision tests 
  12. Electrophysiological tests

However, there may be legitimate reasons to perform these tests. For example
(other reasonable examples are possible):

a.       B-scan ultrasound testing would be medically necessary to assess such
structures for the purpose of surgical decision-making in circumstances where
an adequate view of the intraocular structures cannot be obtained because of
dense cataract,

b.       Glare testing/brightness acuity testing would be medically necessary
in a patient with a complaint of difficulty driving at night, and

c.       Corrected Snellen visual acuity testing under low-contrast conditions
or formal contrast sensitivity testing would be medically necessary to uncover
or demonstrate functional impairments correlated with the patient's symptoms.

In general, any performed ancillary testing must be conducted so as not to
deliberately bias the decision toward the performance of surgery (e.g., glare
testing done on abnormally high settings inconsistent with the instructions of
the testing device's manufacturer, etc.), and must have results and
indications of medical necessity properly documented. Ancillary tests that are
**_not_** routinely indicated in the preoperative workup for cataract surgery
will not be considered a covered benefit unless medical necessity for the
particular patient's circumstances is clearly documented in the patient's
record. (see Documentation Requirements in Local Coverage Article).

**Second Eye Surgery**  
  
Should a significant cataract also be present in the second eye, as supported
by _Cataract in the Adult Eye,_ a "Preferred Practice Pattern" by the American
Academy of Ophthalmology, except in special circumstances, surgery is
generally not performed in both eyes at the same time because of the potential
for bilateral visual loss.  
  
In the more common situation where surgery is performed sequentially in the
other eye on separate days for bilateral visually symptomatic cataracts the
appropriate interval between the first-eye surgery and second-eye surgery is
influenced by several factors:

  1. The patient's visual needs
  2. The patient's preferences
  3. Visual function in the second eye
  4. The medical and refractive stability of the first eye
  5. The need to restore binocular vision and resolve anisometropia,
  6. Allow an adequate interval of time to elapsed to evaluate and treat early postoperative complications in first eye, such as endophthalmitis; and/or
  7. Logistical and travel considerations of the patient.

The patient and the ophthalmologist should discuss the benefits, risks, need,
and timing of second-eye surgery when they have had the opportunity to
evaluate the results of surgery on the first eye, taking into account the
above factors.  
  
If the decision to perform cataract extraction in both eyes is made prior to
the first (sequential) cataract extraction, the documentation must support the
medical necessity for each procedure to be performed.

**Complex Cataract Surgery  **

Note that a procedure coded as "Complex Cataract Surgery" must meet all other
requirements for Cataract Surgery as outlined above and in the associated
Billing and Coding Article A57196.