January 5, 2009

Coding for Glaucoma
For The Record
Vol. 21 No. 1 P. 28

Glaucoma (ICD-9-CM category 365) is a group of conditions resulting in optic nerve damage caused by increased intraocular pressure. It can cause a gradual progression of vision loss if left untreated. Unless patients are having regular eye exams, glaucoma may go undetected because they may not experience any symptoms.

Glaucoma may be primary or secondary. It’s considered primary when the cause is unknown and secondary when the underlying condition is known.

Untreated glaucoma may lead to blind spots in the peripheral vision, tunnel vision, and then total blindness. Although glaucoma cannot be prevented, early detection and treatment can slow and maybe even stop the vision loss.

Types of Glaucoma
• Primary open-angle glaucoma (365.11) is when the drainage channels are partially obstructed and cause the slow drainage of fluid from the eye. A patient may not experience any noticeable signs and symptoms except gradual vision loss, including the gradual loss of peripheral vision in both eyes, which will eventually progress to tunnel vision in the advanced stages. If the open-angle glaucoma is not specified as primary, assign code 365.10. The residual stage of open-angle glaucoma is classified to code 365.15. Assign code 365.01 for open-angle glaucoma with borderline intraocular pressure.

• Acute angle-closure glaucoma, also called closed-angle glaucoma, is when the drainage angle is blocked. Signs and symptoms include severe eye pain, nausea and vomiting, the sudden onset of visual disturbance (often in low light), blurred vision, halos around lights, and reddening of the eye.

Signs and symptoms of a glaucoma attack include a severe headache or pain in the eye/eyebrow area, nausea, blurred vision, and rainbow halos around lights.

The ICD-9-CM code assignment will depend on the specified type of angle-closure glaucoma. Possible codes include the following:

• 365.20, Primary angle-closure glaucoma, unspecified;

• 365.21, Intermittent angle-closure glaucoma;

• 365.22, Acute angle-closure glaucoma;

• 365.23, Chronic angle-closure glaucoma; and

• 365.24, Residual stage of angle-closure glaucoma.

Other types of glaucoma include the following:

• Low-tension glaucoma (365.12) — optic nerve damage even though eye pressure is not elevated.
• Pigmentary glaucoma (365.13) — develops in young or middle-aged adults.

Diagnosis
The following diagnostic tests may be ordered:

• Tonometry — measures the intraocular pressure.

• Test for optic nerve damage — uses an instrument that looks through the pupil to the back of the eye.

• Photographs and drainage of optic nerve — determines the severity of the condition.

• Visual field test — evaluates the peripheral vision.

• Pachymetry — determines the thickness of the cornea. The thickness of the cornea, along with the intraocular pressure reading, may determine whether the patient has glaucoma. Patients with thick corneas with an increased intraocular pressure may not have glaucoma. In addition, patients with thin corneas and normal intraocular pressure readings may have glaucoma.

• Gonioscopy — special lens on the eyes to inspect the drainage angle to determine the type of glaucoma.

• Tonography — measures how quickly fluid drains from the eye.

Treatment
Glaucoma cannot be totally cured, but the intraocular pressure can be reduced by improving the drainage or reducing the fluid. The damage from glaucoma cannot be reversed. However, treatment can slow or prevent further vision loss. Using medicated eyedrops is one way of treating glaucoma. Common medicated eyedrops include the following:

• Beta blockers — reduces the production of fluid.

• Alpha-agonists — reduces the production of fluid and increases drainage.

• Carbonic anhydrase inhibitors — reduces the production of fluid.

• Prostaglandinlike compounds — increases the drainage of fluid from the eye.

• Miotic or cholinergic agents — increases the drainage of fluid from the eye.

• Epinephrine compounds — increases the drainage of fluid from the eye.

Surgery may be used to treat glaucoma if the medications fail. A common surgical procedure is laser surgery, trabeculoplasty (12.59), to relieve the intraocular pressure. If ineffective, a different surgery, trabeculectomy (12.64), may be needed. Eyedrops may still be necessary afterward.

Coding and sequencing for glaucoma 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.