Chapter 7: Diseases of the Eye and Adnexa (H00-H59)

a. Glaucoma

1) Assigning Glaucoma Codes

Assign as many codes from category H40, Glaucoma, as needed to identify the type of glaucoma, the affected eye, and the glaucoma stage.

2) Bilateral glaucoma with same type and stage

When a patient has bilateral glaucoma and both eyes are documented as being the same type and stage, and there is a code for bilateral glaucoma, report only the code for the type of glaucoma, bilateral, with the seventh character for the stage. When a patient has bilateral glaucoma and both eyes are documented as being the same type and stage, and the classification does not provide a code for bilateral glaucoma (i.e. subcategories H40.10, H40.11 and H40.20) report only one code for the type of glaucoma with the appropriate seventh character for the stage.

3) Bilateral glaucoma stage with different types or stages

When a patient has bilateral glaucoma and each eye is documented as having a different type or stage, and the classification distinguishes laterality, assign the appropriate code for each eye rather than the code for bilateral glaucoma. When a patient has bilateral glaucoma and each eye is documented as having a different type, and the classification does not distinguish laterality (i.e. subcategories H40.10, H40.11 and H40.20), assign one code for each type of glaucoma with the appropriate seventh character for the stage. When a patient has bilateral glaucoma and each eye is documented as having the same type, but different stage, and the classification does not distinguish laterality (i.e. subcategories H40.10, H40.11 and H40.20), assign a code for the type of glaucoma for each eye with the seventh character for the specific glaucoma stage documented for each eye.

4) Patient admitted with glaucoma and stage evolves during the admission

If a patient is admitted with glaucoma and the stage progresses during the admission, assign the code for highest stage documented.

5) Indeterminate stage glaucoma

Assignment of the seventh character "4" for "indeterminate stage" should be based on the clinical documentation. The seventh character "4" is used for glaucomas whose stage cannot be clinically determined. This seventh character should not be confused with the seventh character "0", unspecified, which should be assigned when there is no documentation regarding the stage of the glaucoma.