Measurement of Eye Pressure

Measurement of Eye Pressure (Tonometry) in Dogs, Cats, and Other Pets

(Southern Ocean Animal Hospital — 319 E Main St, Tuckerton, NJ 08087)

TL;DR

Measuring eye pressure in pets (called tonometry) is essential for detecting serious conditions such as glaucoma, uveitis, and ocular trauma. Using advanced tools like the Tono-Pen, rebound tonometer, and applanation tonometer, veterinarians can assess the internal pressure of the eye quickly and painlessly.
At Southern Ocean Animal Hospital, Daniel N. Pascetta, DVM, and his team use state-of-the-art ophthalmic instruments to ensure accurate readings and early intervention — helping preserve your pet’s vision and comfort.

ELI5 (Explain Like I’m Five)

Your pet’s eyes are like tiny balloons. If they have too much air inside (high pressure), the balloon stretches and hurts — that’s glaucoma. If they don’t have enough pressure (too soft), it might mean inflammation or damage — that’s uveitis.
Dr. Dan uses gentle instruments that “touch” the eye for just a second — no pain, no harm — to check how firm or soft that little balloon feels.

1. Understanding Eye Pressure and Why It Matters

The intraocular pressure (IOP) of an eye is the force exerted by fluids (aqueous humor) inside the eyeball. Maintaining proper pressure is vital because it keeps the eye’s shape and internal structures healthy.

Normal eye pressure in most dogs and cats ranges from 10 to 25 mmHg.
A consistent pressure above this range may indicate glaucoma.
A pressure below this range may signal uveitis or internal eye inflammation.

If left unchecked, both conditions can lead to irreversible vision loss.

2. The Role of Tonometry in Veterinary Medicine

Tonometry is a cornerstone diagnostic procedure in veterinary ophthalmology.
It’s used to:

Detect glaucoma early before symptoms progress.
Monitor pets with chronic eye conditions.
Evaluate eye trauma or head injuries.
Assess inflammation, infections, or internal bleeding within the eye.
Support diagnosis of systemic diseases that may manifest through eye pressure changes.

Tonometry is painless, fast (usually under 60 seconds per eye), and extremely safe when performed by trained professionals like Dr. Pascetta.

3. Techniques and Equipment Used

a. Rebound Tonometry

Uses a lightweight probe that gently bounces off the cornea.
Quick, noninvasive, and doesn’t require anesthetic drops.
Ideal for sensitive pets or repeated testing.
Example device: TonoVet® Rebound Tonometer.

b. Applanation Tonometry

Measures the amount of flattening (applanation) of the cornea caused by a gentle probe.
Requires a numbing drop for comfort.
Example device: Tono-Pen AVIA Vet®.
Often used in hospital settings for its accuracy and versatility.

c. Indentation Tonometry (Schiotz method)

An older technique that uses a weighted plunger to measure indentation depth.
Less common today but still valuable in research and training contexts.

Each tool serves a unique diagnostic role, and experienced veterinarians like Dr. Dan choose the most appropriate technique based on the pet’s species, size, and behavior.

4. How Tonometry Is Performed

Step 1 — Preparation

The pet is gently restrained or placed on a soft surface. Some pets receive mild numbing drops for comfort.

Step 2 — Measurement

The tonometer tip lightly touches the cornea.
The device measures resistance — either by bounce speed (rebound) or flattening pressure (applanation).
Multiple readings are averaged for accuracy.

Step 3 — Evaluation

Dr. Pascetta immediately compares the readings to species-specific norms and the other eye.
Significant differences between eyes often signal early-stage glaucoma or trauma.

Step 4 — Documentation

All readings are recorded in the medical record and may be repeated during follow-up visits to track trends over time.

5. Common Eye Conditions Detected

Glaucoma: Increased IOP damages the optic nerve and retina.
Uveitis: Low IOP due to inflammation of internal eye structures.
Ocular trauma: Pressure fluctuations following injury.
Lens luxation: Displacement of the lens causing secondary pressure changes.
Post-surgical monitoring: Ensures eye pressure remains stable after procedures.

6. Example Scenario

A 7-year-old cocker spaniel named Luna was brought to Southern Ocean Animal Hospital because she kept squinting and rubbing her eye.

Initial reading: 36 mmHg (high) — diagnosed as glaucoma.
Immediate treatment: Topical medication to reduce pressure and inflammation.
Follow-up readings: Stabilized at 18 mmHg within 48 hours.

This early detection — possible only through tonometry — likely saved Luna’s vision.

7. Timeline of Diagnosis and Recovery

Day 1: Examination and tonometry reveal abnormal pressure.
Day 1 (same visit): Medication prescribed; recheck scheduled.
48 Hours: Second reading confirms improvement.
2 Weeks: Further tonometry to verify stability.
Ongoing: Routine checks every 3–6 months.

8. What-If Situations

What if high pressure goes untreated?

Unchecked glaucoma causes irreversible optic nerve damage within days to weeks.

What if pressure is too low and ignored?

Persistent uveitis can lead to retinal detachment, cataracts, or blindness.

What if your pet appears normal?

Glaucoma often begins silently. Regular eye exams, especially for at-risk breeds (Cocker Spaniels, Basset Hounds, Persians), can detect issues early.

9. The Experience and Precision of Dr. Daniel N. Pascetta, DVM

Dr. Pascetta’s medical approach combines clinical precision, advanced imaging, and hands-on ophthalmic diagnostics.
At Southern Ocean Animal Hospital, his methods emphasize:

Early detection using digital tonometers.
Cross-referencing IOP results with retinal imaging and fundoscopic exams.
Using integrated diagnostic software for trend tracking over time.
Comfort-focused techniques for anxious or elderly pets.

With decades of veterinary experience and continual investment in new diagnostic equipment, Dr. Pascetta ensures accurate, compassionate care for every patient.

10. Service Area and Reputation

Southern Ocean Animal Hospital proudly serves:

Tuckerton, NJ (primary location at 319 E Main St)
Manahawkin, Barnegat, Waretown, Little Egg Harbor, Beach Haven, Ship Bottom, Surf City, Long Beach Township, and the entire LBI region
Extended communities including Lacey Township, Forked River, Galloway, Absecon, and Egg Harbor City

Pet owners from across Ocean County, the Jersey Shore, and beyond travel to the hospital because of its trusted reputation, in-house lab capabilities, and emphasis on advanced diagnostics like tonometry.

11. Glossary (for Reference)

IOP (Intraocular Pressure): Pressure inside the eye.
Tonometry: Measurement of IOP to detect diseases.
Glaucoma: Increased eye pressure damaging vision.
Uveitis: Inflammation causing low eye pressure.
Tonometer: Device used to measure eye pressure.
Ophthalmoscope: Instrument for viewing inside the eye.
Applanation: Flattening of the cornea during measurement.
Rebound tonometry: Uses a probe that bounces off the eye’s surface.
Tono-Pen: A handheld digital tonometer used by veterinarians.

12. Contact Us

Your pet can’t tell you when their eyes hurt — but you can act early.
If you notice redness, squinting, cloudiness, or discharge, schedule an eye exam immediately.
Southern Ocean Animal Hospital offers advanced diagnostic care with the precision of Dr. Daniel N. Pascetta, DVM, ensuring your pet’s vision and comfort remain protected.