LOINCActive
LOINC Code 28770-6: Maddox double prism test for Heterophoria
Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026
What is this code?
LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Heterophoria. It is commonly used with the system or sample type Eyes.
When is it used?
- Used in lab systems, EHRs, and clinical data exchange.
- May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
- Status: ACTIVE
- Method: Maddox double prism test
What it does not mean
- The code identifies the observation or test, not the actual result.
Key facts
- Maddox double prism test for Heterophoria
- Heterophoria
- Used for determination of cyclodeviations. Done by usina a red and white Maddox rod, one placed in front of one eye and the other placed in front of the other eye.
- Double Maddox rod test; Eye; EYE.HETEROPHORIA; Identity or presence; Nominal; Ophthalmologic; Ophthalmology; Ophtho; Ophthy; Point in time; Random; Vision; Visual
Where you may see this code
You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.
Common synonyms
Maddox double prism test for HeterophoriaMaddox double prism testHeterophoriaEYE.HETEROPHORIAPridPtEyes
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.