Medical coding is the translation of clinical documentation into standardized codes used for billing. Understanding coding fundamentals is essential for the CPO (Certified Paraoptometric) certification exam, as front office and billing staff must accurately record services, assign diagnoses, and support clean claim submission. Coding errors directly affect practice revenue, audit risk, and compliance.
The Two Code Systems: CPT and ICD-10
Key Optometry CPT Codes
| CPT Code | Description | When Used |
|---|
Common ICD-10 Diagnosis Codes in Optometry
- H52.13 — Myopia, bilateral
- H52.03 — Hypermetropia (hyperopia), bilateral
- H52.23 — Regular astigmatism, bilateral
- H52.4 — Presbyopia
- H40.11 — Primary open-angle glaucoma (POAG)
- H35.30 — Unspecified macular degeneration
- E11.3519 — Type 2 DM with diabetic retinopathy, unspecified severity
- H04.123 — Dry eye syndrome, bilateral
- H26.9 — Unspecified cataract
- Z01.00 — Encounter for eye examination without abnormal findings
The Billing Workflow
Patient Registration
Collect demographic and insurance information; verify eligibility before the appointment.
N: 1
Appointment / Encounter
Patient is seen; clinical documentation is completed by the provider.
N: 2
Superbill Completion
Provider or staff selects appropriate CPT and ICD-10 codes on the superbill/charge ticket.
N: 3
Claim Creation
Billing staff enters charges into the practice management system (PMS) and generates the claim (CMS-1500 form or electronic equivalent).
N: 4
Claim Submission
Claim is submitted to the insurance plan electronically (EDI) or by paper. Clearinghouses verify formatting before forwarding to payer.
N: 5
Payment / Remittance
Payer processes the claim, sends the ERA (Electronic Remittance Advice) or paper EOB, and issues payment.
N: 6
Patient Balance
Any balance owed by the patient (copay, deductible, non-covered services) is invoiced to the patient.
N: 7