In this blog post, we’ll discuss coding guidelines related to Eye and Adnexa which comes under Chapter 7 of the ICD-10-CM official guidelines. Laterality for most of the categories in chapter seven designates specific codes for the right eye, left eye, and bilateral (both eyes). You may see the physician’s documentation state OD - oculus dexter (right eye), OS- oculus sinister (left eye), or OU- oculus utro (both eyes) rather than right, left or bilateral. Often times tests are performed on both eyes as a comparison however the patient may have a condition specific to just one eye. It’s important to read the documentation thoroughly to capture the laterality for the most specific code to be assigned to support the medical necessity of the service. ICD-10-CM assigns the code number for laterality as follows:
- 1–is the right eye
- 2–is the left eye
- 3–indicates bilateral
- 9–means the side is unspecified
Let’s move on to diseases of the eye. Glaucoma is very common among the older population. It is a disease of the eye in which fluid pressure within the eye builds up. This occurs when the fluid that flows in and out of the anterior chamber drains too slowly or gets clogged. This leads to fluid build-up, and pressure inside the eye. This high pressure can damage the optic nerve and result in vision loss.
When assigning Glaucoma codes, ICD-10-CM indicates that as many as codes form category H40 should be assigned to identify the specific type of Glaucoma, the affected eye as well as the stage. For example, a patient is suffering from primary open-angle glaucoma of the right eye with moderate stage.
The correct code assignment for this scenario is: H40.1112 Primary open angle glaucoma, Right eye, Moderate stage.
This is fairly straightforward, right? But as with many coding scenarios, things can get complicated. It all becomes more challenging when the patient has Glaucoma in both eyes. When a patient has bilateral Glaucoma and the same type and stage, assign the bilateral code. When a patient has a different type and/or a different stage, assign a separate code for each eye with the proper type, laterality, and appropriate 7th character for the stage. Do not assign a bilateral code. Keep in mind that not all types of Glaucoma require a stage. Watch for the 7th character indicator.
You can find some really great information in the ICD-10 Glaucoma Reference Guide from the American Academy of Ophthalmology which is very helpful in deciphering how to code patients with Glaucoma.
With all things coding, reviewing the documentation carefully is the key to accurate coding. Reading all guidelines and specific code category instructions guide us to proper sequencing and selection of correct codes.