Corneal Topography/Computer-Assisted Photokeratoscopy
DESCRIPTION
Corneal topography describes measurements of the curvature of the cornea. Various techniques and instruments are available to measure corneal topography:
The keratometer (ophthalmometer), the most commonly used instrument, projects an illuminated image onto a central area in the cornea. The fact that the keratometer can only estimate the corneal curvature over a small percentage of its surface, and that estimates are based on the frequently incorrect assumption that the cornea is spherical, are limitations of this technique.
The keratoscope is an instrument that reflects a series of concentric circular rings off the anterior corneal surface. Visual inspection of the shape and spacing of the concentric rings provides a qualitative assessment of topography. A photokeratoscope is a keratoscope equipped with a camera, which can provide a permanent record of the corneal topography.
Computer-assisted photokeratoscopy is an alternative to keratometry or keratoscopy in measuring corneal curvature. This technique uses sophisticated image analysis programs to provide quantitative corneal topographic data.
POLICY
An evaluation of corneal topography for the accurate diagnosis and follow-up of certain corneal disorders, such as keratoconus, is considered medically necessary.
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
SOURCES
BlueCross BlueShield of Tennessee network physicians. June-July 2011.
BlueCross BlueShield Association, Medical Policy Reference Manual. (4:2011). Corneal topography / computer-assisted photokeratoscopy (9.03.05). Retrieved July 7, 2011 from BlueWeb. (4 articles and/or guidelines reviewed)
National Guideline Clearinghouse. (2007). American Academy of Ophthalmology Refractive Management/Intervention. Refractive errors & refractive surgery. Retrieved October 9, 2008 from http://www.guideline.gov/summary/summary.aspx?doc_id=11754&nbr=006058&string=%22Refractive+errors%22+and+%22refractive+surgery%22.
ORIGINAL EFFECTIVE DATE: 12/14/1998
MOST RECENT REVIEW DATE: 7/7/2011
ID_BT
Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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