Get a Closer View of ICD-10-CM Glaucoma Coding

Get a Closer View of ICD-10-CM Glaucoma Coding

Laterality and stage of condition are key areas
to keep an eye on in physician documentation.

More than 3 million people in the United States suffer from glaucoma. The disease is a leading cause of blindness worldwide. It’s incurable, and vision lost cannot be regained; however, medication and surgical procedures can halt the loss of vision.

Types of Glaucoma

The optic nerve may become damaged due to eye pressure. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a sponge-like meshwork that acts as a drain, and then leaves the eye. Glaucoma is classified as closed or open angle.

Closed-angle Glaucoma

Closed-angle glaucoma often presents with acute symptoms such as eye pain and blurred vision, and is considered an emergency.
Closed-angle glaucoma is less frequent than open-angle. Poor drainage is caused by the angle between the iris and the cornea becoming too narrow and physically blocked by the iris. This condition leads to a sudden buildup of pressure in the eye.

Open-angle Glaucoma

In open-angle glaucoma, even though the drainage angle is “open,” fluids pass too slowly through the drain and build up, causing pressure in the eyes to rise to a level that damages the optic nerve. Another risk factor for optic nerve damage relates to blood pressure. Not everyone who develops increased eye pressure develops glaucoma; each patient handles the pressure differently.
Primary open-angle glaucoma reduces blood flow and damages the optic nerve. It also causes optic neuropathy — a condition that causes the axons of the optic nerve to die. Primary open-angle glaucoma is more prevalent than open-angle glaucoma, and is considered the leading cause of irreversible blindness in the world. The condition is less common in those under 40 years of age, and more common in those over 70 years of age.
The leading causes of risk include:

  • Age
  • Increased intraocular pressure
  • History of fracture
  • Race
  • Family history
  • Diabetes
  • Poor vision
  • Certain medications

Primary open-angle glaucoma usually results from decreased outflow of aqueous fluid due to an acceleration and exaggeration of normal aging changes in the anterior chamber angle, iris, and ciliary body tissues of the eye. It generally occurs bilaterally, but it isn’t always symmetrical in the stage progression.
Secondary open-angle glaucoma may result from a variety of substances that mechanically block the outflow of aqueous fluid through the anterior chamber angle.
Glaucoma can develop without increased eye pressure. This is called low-tension or normal-tension glaucoma. It’s a type of open-angle glaucoma. Less common causes of glaucoma include a blunt or chemical injury to the eye, severe eye infection, blockage of blood vessels in the eye, inflammatory conditions of the eye, and eye surgery to correct another condition. The condition can form in both eyes at different stages.

ICD-10-CM Coding

Diagnosis codes for glaucoma include laterality and the stage of the condition. “Unstageable” means the physician is unable to determine the stage, not that the physician did not document the stage. For lack of documentation, use an unspecified code.

Quality Reporting Is Key in 2017

New for 2017, ICD-10-CM adds laterality codes for glaucoma conditions that were previously missing. Coders and clinicians must work together to ensure that all of the required documentation elements are captured to assign the appropriate code. Glaucoma is a measure for the Physician Quality Reporting System and is included in risk adjustment measures. The transition to value-based payment models solidifies the need to correctly document and capture these codes.


Rhonda Buckholtz, CPC, CPMA, CPC-I, CRC, CHPSE, CENTC, COBGC, CPEDC, CGSC, is vice president of strategic development at AAPC.

Rhonda Buckholtz

About Has 38 Posts

Rhonda Buckholtz, CPC, CPMA, CRC, CDEO, CMPE, CHC, COPC, AAPC Approved Instructor, is owner of Coding and Reimbursement Experts. She spends her time helping physician practices achieve operational excellence, compliance, education, and Lean Six Sigma through her consulting. Buckholtz has more than 30 years of experience in healthcare management, compliance, and reimbursement/coding sectors. She was responsible for all ICD-10 training and curriculum at AAPC during the transition from ICD-9. Buckholtz has authored numerous articles for healthcare publications and she has spoken at numerous national conferences for AAPC and others. She is past co-chair for the WEDI ICD-10 Implementation Workgroup, Advanced Payment Models Workgroup, and she provided testimony for ICD-10 and standardization of data for National Committee on Vital and Health Statistics. Buckholtz is on AAPC’s National Advisory Board.

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