Optical Coherence Tomography of the Peripheral Nerve Layer (PNT)
This test uses advanced imaging technology to examine the structure of nerve fibers in your eyes, specifically the retinal nerve fiber layer, to assess potential nerve damage or disease.
["This helps doctors evaluate vision-related nerve health, often linked to conditions like glaucoma or other optic neuropathies."]
Key facts at a glance
- LOINC
- 57119-0
- Short code
- Optical coherence tomography Pnl
- Synonyms
- Optical coherence tomography Pnl
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- oct
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
Optical Coherence Tomography (OCT) creates high-resolution cross-sectional images of the retinal nerve fiber layer (RNFL) in your eyes. This layer contains tiny nerve fibers that transmit visual information from your retina to your brain. The test focuses on the peripheral nerve layer (PNT) to detect early signs of nerve thinning or abnormalities that may indicate conditions affecting vision or nerve function.
Why It’s Done
Your healthcare provider may order this test if you have symptoms like vision changes, eye pain, or a family history of nerve-related eye diseases. It’s also used to monitor existing conditions like glaucoma, diabetic retinopathy, or optic neuritis to track progression or response to treatment.
Sample Collection and Procedure
No special preparation is needed. You’ll sit comfortably with your eyes dilated (using drops) to allow the imaging device to capture clear images. The procedure takes about 10–15 minutes and is painless—similar to a routine eye exam.
What to Expect After the Test
You may experience mild discomfort from dilated eye drops, which can cause blurred vision for a few hours afterward. Follow-up visits may be scheduled to compare results with previous scans.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Changes in the peripheral nerve layer detected by OCT can indicate underlying nerve damage or disease. Early detection of thinning or irregularities may help diagnose conditions like glaucoma, optic nerve diseases, or systemic disorders affecting nerves. Regular monitoring can guide treatment decisions or track disease progression.
Short name
PNT OCT
Frequently asked questions
How long does it take to get results?
Is this test covered by insurance?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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