Phocflu
The ocular fluid pH test measures the acidity or alkalinity of fluid from the eye, helping doctors assess eye health and diagnose certain eye conditions.
{"This test measures the pH (acidity level) of fluid from inside your eye","It helps diagnose infections, inflammation, or other eye conditions","Sample is collected during a specialized eye procedure, not from blood"}
Key facts at a glance
- LOINC
- 42728-6
- Short code
- pH Ocular
- Synonyms
- pH Ocflu
- Category
- chemistry
- Sample
- serum
- Container
- Sterile plastic or glass container, preferably with tight seal to prevent CO2 exchange
- Units
- not specified
- Ref low
- 7
- Ref high
- 7.4
- Critical range
- 6.5 not specified – 7.8 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- Potentiometry using pH electrode or glass pH meter
- CPT
- 92235 or 92230
- SNOMED
- 271577006
- Specimen volume
- 0.1 to 0.5 mL minimum
- Stability
- Analyze immediately; unstable. pH changes occur within minutes due to CO2 exchange with air. If delay unavoidable, keep specimen airtight on ice and analyze within 30 minutes.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
What is this test?
The ocular fluid pH test measures the pH level (how acidic or alkaline) of the fluid inside your eye. Ocular fluid includes vitreous humor (the gel-like substance in the back of the eye) and aqueous humor (the fluid in the front chamber of the eye). Maintaining proper pH balance is essential for eye health and proper vision.
How is the sample collected?
Unlike common blood tests, ocular fluid is collected during a specialized eye procedure such as a vitrectomy or anterior chamber paracentesis. This is performed by an ophthalmologist (eye specialist) in a clinical setting. The eye is first numbed with anesthetic drops, and a small needle is used to extract a tiny amount of fluid from the eye for testing.
Why might I need this test?
Your doctor may order this test if you have symptoms of eye infection, inflammation (uveitis), or other ocular conditions. The pH level can change when the eye is diseased or infected, providing valuable diagnostic information. It may also be used to monitor certain eye conditions or evaluate the effectiveness of treatment.
Reference range
7.0-7.4not specified
No special preparation; sample obtained by ophthalmologist during procedure
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is the test painful?
How long does it take to get results?
What is the normal pH of ocular fluid?
Do I need to fast before this test?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy