ICD-9 and ICD-10 share many similarities. When using a tool such as ICD-10-CM for Ophthalmology, it remains best practice to look up the main term in the alphabetical index and cross-reference the diagnosis in the tabular list. This will ensure that all specifics of the diagnosis are met. Many diseases in ICD-10 are still categorized in the same method and with the same language as ICD-9.
When choosing a diagnosis, continue coding to the highest specificity available. In ICD-9, we code to the fifth digit. In ICD-10, we may code to the seventh digit. The best code is the actual diagnosis. The next best is a sign or symptom. Never code anything you only suspect — be sure to rule it out.
Below are a few of the nuances that you’ll encounter in ICD-10.
0 vs. O
Be mindful when submitting 0 (zero) or O (capital O). ICD-10 codes begin with letters of the alphabet rather than numbers. That small difference can mean getting claims paid the first time or experiencing a delay in payment.
O24.414 Gestational diabetes mellitus in pregnancy, insulin controlled
H02.224 Mechanical lagophthalmos of left upper lid
X Placeholder
X marks the spot as a placeholder and, in ICD-10, also denotes a potential expansion of the code. If you fail to use the X when a placeholder is required, it will result in an invalid code.
H21.1X3 Other vascular disorders of iris and ciliary body, bilateral
When you need to indicate glaucoma staging in the code, you must indicate it in the seventh character of the code. Because the base ICD-10 code is only five digits long, insert X in the sixth position and put the appropriate glaucoma-stage indicator (here, 1 for mild stage) in the seventh position.
H40.11X1 Primary open-angle glaucoma, mild stage
Dash (-)
A dash at the end of ICD-10 codes in the alphabetical index shows the need for additional characters. If a code is submitted without all of the appropriate characters, it will be denied.
For example, a search for aphakia in the alphabetical index results in H27.0-. This dash shows that you need to add the appropriate additional character to complete the code. By searching the tabular list, you’ll find the following:
H27.01 Aphakia, right eye
H27.02 Aphakia, left eye
H27.03 Aphakia, bilateral
Laterality
Some ICD-10 codes require laterality; others do not. For example, presbyopia H52.4 and blurred vision H53.8 do not include laterality. If you add an additional character to indicate a specific eye, the submitted claim would be denied.
When codes do include laterality, they follow a set numbering convention: 1-right, 2-left or 3-bilateral. However, some codes may only let you specify right or left eye, while others may give you all three options. Eyelid codes complicate the matter by having similar numeration — 1-right upper, 2-right lower, 4-left upper and 5-left lower.
H11.031 Double pterygium of right eye
H11.032 Double pterygium of left eye
H11.033 Double pterygium , bilateral
H01.021 Squamous blepharitis, right upper lid
H01.022 Squamous blepharitis, right lower lid
H01.024 Squamous blepharitis, left upper lid
H01.025 Squamous blepharitis, left lower lid
When a diagnosis is bilateral, but the code does not include laterality, it is appropriate to list each eye.
H02.31 Blepharochalasis, right upper lid
H02.34 Blepharochalasis, left upper lid
If the code does not require laterality, only list it once. Age-related macular degeneration codes do not include laterality. For a patient that has exudative age-related macular degeneration in both eyes, the appropriate code submission is H35.32.
Excludes 1 Notes
The term “Exclude 1” is used in ICD-10 to indicate mutually exclusive codes, that is, two conditions that you cannot report together.
H35.35- Cystoid macular degeneration
- Excludes 1: cystoid macular edema following cataract surgery (H59.03-)
For more information on ICD-10, visit www.aao.org/icd10. There you’ll find additional coding guides, such as glaucoma and strabismus, plus other useful tools to help you bill correctly the first time.
* * *
About the authors: Sue Vicchrilli, COT, OCS, is the Academy’s director of coding and reimbursement and the author of EyeNet’s “Savvy Coder” column and AAOE’s Coding Bulletin, Ophthalmic Coding Coach and Ophthalmic Coding series. Jenny Edgar, CPC, CPCO, OCS, is the Academy’s coding specialist. She oversees the Academy’s Chart Auditing Service and is also a contributing author to the Ophthalmic Coding Coach and Ophthalmic Coding series.