There are 123 pending changes to coding for ophthalmology for this coming October due to additions, deletions, and revisions of the ICD-10 coding set. The coding for conditions related to the eye in ICD-10-CM has become much more in-depth and requires the coder to have a greater understanding of anatomical structure and pathophysiology.
Today I am going to focus on glaucoma. More than 3 million people suffer from glaucoma in the U.S. It is the second-leading cause of blindness. Glaucoma is not curable and vision lost cannot be regained. Medication and surgical procedures can halt the loss of vision, however. In the U.S., more than 120,000 individuals are blind from glaucoma.
Glaucoma is classified as closed- or open-angle. Closed-angle glaucoma often presents with acute symptoms such as eye pain and blurred vision and is considered an emergency. Primary open-angle glaucoma (POAG) is the more prevalent form of glaucoma and is a leading cause of impaired vision. It reduces the blood flow and damages the optic nerve, and it is considered the leading cause of irreversible blindness in the world. It also causes optic neuropathy, in which the axons of the optic nerve die. The condition is much rarer in those under 40 and more common in those over 70.
The leading causes of risk include:
- Increased IOP
- History of fracture
- Family history
- Poor vision
- Certain medications
Studies show that the optic nerve gets damaged due to eye pressure. In the front of the eye is a space called the anterior chamber. There is a clear fluid that 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 leaves the eye.
In open-angle glaucoma, even though the drainage angle is “open,” the fluid passes too slowly through the drain and the fluids build up, causing the 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 the increased eye pressure will develop glaucoma, as each patient handles the pressure differently than others.
Glaucoma can develop without increased eye pressure. This is called low-tension or normal-tension glaucoma. It is 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 occasionally, eye surgery to correct another condition.
It can form in both eyes at different stages.
Closed-angle glaucoma is less frequent and poor drainage is caused because the angle between the iris and the cornea is too narrow and is physically blocked by the iris. This condition leads to a sudden buildup of pressure in the eye.
Coding for glaucoma in ICD-10-CM includes laterality as well as the stage of the condition. Staging glaucomatous damage into categories of damage such as, mild, moderate, and advanced enhances condition management. It helps promote careful assessment and documentation of clinical damage, thus facilitating monitoring for stability versus progression and provides a common language for both clinical and research purposes. This common language then can be captured in the coding system. Be careful to note that the codes for unstageable do not include lack of physician documentation as to the stage, but rather when the physician is unable to determine the stage. For lack of documentation you would utilize an unspecified code.
Laterality codes for glaucoma conditions that were previously missing are new for 2017.