Optometry Coding & Billing Alert

Documentation of ‘regular’ vs. ‘irregular’ will help ease your coding.

Astigmatism is probably one of the most common conditions that your optometrist treats, but selecting the correct ICD-10 code for this condition isn’t always routine. Consider the following tips when choosing between diagnosis codes for this common issue.

Differentiate Irregular From Regular

Choosing the appropriate ICD-10 code from the H52.2 (Astigmatism) category will depend on your ability to determine whether the patient has regular astigmatism or irregular. It’s up the optometrist to denote which type the patient has, but it’s a good idea to understand the differences.

Regular astigmatism — which is the more common of the two — occurs when the patient’s principal meridians are perpendicular to one another. Patients with irregular astigmatism don’t have principal meridians that are 90 degrees apart, making this condition less common.

To report regular astigmatism, you’ll choose a code from the H52.22 (Regular astigmatism) range, whereas H52.21 (Irregular astigmatism) will be more accurate for patients with irregular astigmatism. If the physician doesn’t specify which type the patient has, then you’ll select a code from the H52.20 (Unspecified astigmatism) series.

Remember Those Sixth Digits

Once you’ve selected the correct code range for your patient, you’ll also add a sixth digit, depending on which eye is affected. The following sixth digits are your options when choosing an astigmatism code:

1. Right eye
2. Left eye
3. Bilateral
4. Unspecified eye

Therefore, if you see a patient with regular astigmatism of both eyes, you’ll report H52.223 (Regular astigmatism, bilateral).

Coder tip: Insurers want you to code as accurately as possible, so if your optometrist frequently fails to document the type of astigmatism or the affected eye(s), you should sit down with her and let her know that chronically submitting vague and unspecified codes could lead to delays in reimbursement, or even denials.