March 5, 2007

Coding for Macular Degeneration
For The Record
Vol. 19 No. 5 P. 32

Macular degeneration is a chronic eye condition that occurs because of deterioration of the tissue in the macula—the central portion of the retina responsible for central vision. Sometimes referred to as age-related macular degeneration, it is the leading cause of severe vision loss in people aged 60 and older. It may not occur in both eyes at first, but eventually, both eyes are usually affected. Although it does not lead to total blindness, it can cause blurred central vision or a blind spot in the center of the visual field. Typically, the condition does not affect peripheral vision.

Macular degeneration is a gradually progressive disease that is nonreversible. The first signs of macular degeneration include the following:

• the need for more light when doing close-up work;

• small lettering may be harder to read; and

• road signs are more difficult to recognize.

Types of Macular Degeneration
Macular degeneration can be classified as dry or wet. Dry macular degeneration is characterized by the presence of yellow deposits, called drusen, in the macula. Macular degeneration generally starts in the dry form and is classified to ICD-9-CM code 362.51.

Wet macular degeneration (362.52) is characterized by the growth of abnormal blood vessels from the choroid underneath the macula. Retinal pigment epithelial detachment is a form of wet macular degeneration that occurs when fluid leaks from the choroid under the retinal pigment epithelium (RPE). Retinal pigment epithelial detachment is classified to code 362.42. This code also includes exudative detachment of RPE. Hemorrhagic detachment of RPE is classified to code 362.43.

Other types of macular degeneration include the following:

• unspecified—362.50;

• atrophic; nonexudative—362.51;

• disciform; exudative—362.52;

• cystoid—362.53;

• cystic; hole; pseudohole—362.54;

• juvenile—362.75;

• Best’s (disease); hereditary—362.76; and

• familial pseudoinflammatory—362.77.

Symptoms
The following are the common symptoms of dry macular degeneration:

• need for bright light to read;

• straight lines start to appear distorted;

• difficult to adapt to low levels of light;

• increased blurriness of printed words;

• decrease in intensity or brightness of colors;

• difficulty recognizing faces;

• increase in haziness of overall vision; and

• blurred or blind spot in central vision.

The symptoms for wet macular degeneration include the following:

• visual distortions;

• decrease in or loss of central vision; and

• central blurry spot.

Diagnosis
Macular degeneration is diagnosed during a thorough eye examination. The physician will look for drusen and mottled pigmentation in the macula. In addition, the physician may have the patient look at an Amsler grid, which looks like a checkerboard. This test can determine the location and extent of the macular damage.

The physician may also choose to perform a fluorescein angiography to evaluate the extent of the damage to the macula. Another test that may be done is optical coherence tomography which identifies the area of retinal thickening or thinning.

It is extremely beneficial to diagnosis macular degeneration early. Although the condition cannot be prevented or cured, early diagnosis can delay or reduce the severity of it.

Treatment
Although the damage from macular degeneration cannot be reversed, early treatment can slow progression. The following are some treatment methods for macular degeneration:

• Photocoagulation is a laser beam used to create small burns in areas with abnormal blood vessels.

• Photodynamic therapy combines a cold laser and a light-sensitizing drug called verteporfin that’s injected into the bloodstream.

• Submacular surgery removes the abnormal blood vessels.

• Macular translocation surgery detaches the retina, shifts the fovea away from the choroidal neovascularization (CNV), and relocates it over healthy tissue.

• Medications called anti-vascular endothelial growth factor may be used to stop new CNV by blocking the effects of a growth factor these blood vessels need to thrive. Some medications include pegaptanib (Macugen), ranibizumab (Lucentis), and bevacizumab (Avastin) and are injected directly into the eye.

Coding and sequencing for macular degeneration are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.