By Judy Monestime bio
Chapter 7 of ICD-10 CM codes in the range of H40-H42 describes specific forms of glaucoma. The official guidelines describe the requirement to assign as many codes from category H40 as needed to identify the type of glaucoma, the affected eye, and the glaucoma stage. The stage of glaucoma is specified with the seventh character:
0-Stage Unspecified
1-Mild Stage
2-Moderate Stage
3-Severe Stage
4-Indeterminate Stage
According to the official guidelines, assignment of the seventh character to “4- 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.”
Patients who develop glaucoma as a result of corticosteroid therapy are classified to subcategory H40.6. The “use additional code” note appears beneath subcategory H40.6 to code the drug that is causing the adverse effect of glaucoma that would be in the range of T36-T50 with the fifth or sixth character 5.
H40.6 Glaucoma secondary to drugs
Use additional code for adverse effect, if applicable, to identify drug (T36-T450 with fifth or sixth character 5)
One of the following seventh characters is to be assigned to each code in subcategory H40.6 to designate the stage of glaucoma
0 – stage unspecified
1 – mild stage
2 – moderate stage
3 – severe stage
4 – indeterminate stage
Lastly, if documentation in the medical record states glaucoma only, code H40.9, Unspecified glaucoma, should be assigned. Clarify the following before coding glaucoma:
- Laterality
- Type of Glaucoma (i.e. ocular hypertension, primary angle closure, etc.)
- Stage (0-4)
- Causes and underlying disease processes.
Let’s practice! How do you code the following?
The 58-year-old male patient has moderate, primary open-angle glaucoma and age-related bilateral exudative macular degeneration. Patient is admitted because of abnormally high intraocular pressure. What are the correct diagnosis codes for this case?
H40.11X2 – Primary open-angle glaucoma
H35.32 – Exudative age-related macular degeneration
Rationale: Review of the Tabular at code H40.11 indicates the need for a seventh character to designate the stage of the glaucoma. Primary open-angle glaucoma is characterized by visual field abnormalities and intraocular pressure that is too high for the continued health of the eye. Exudative age-related macular degeneration is assigned to code H35.32. In this case, ICD-10-CM does not have separate codes to identify specific eyes.
Judy Monestime, MBA, CDIP, CPC, is an AHIMA-approved ICD-10-CM/PCS trainer.
