Tonometry in Veterinary Medicine
Tonometry is the measuring of an animal's eye pressure (intraocular pressure) to detect signs of glaucoma or other eye diseases. A handheld device called a tonometer is used by veterinarians to evaluate IOP in animals and to determine reference values in younger animals.
Eye Diseases in Cats, Dogs & other Large & Small Animals
The most common eye disease in animals is glaucoma. Glaucoma is a disease in which pressure within the eye increases to dangerous levels. This increase in pressure can permanently damage the retina and optic nerve. Glaucoma often causes headaches and, if not treated, results in loss of vision.
Typical clinical symptoms are a painful or squinting eye, excessive tearing, redness of the sclera, clouding of the cornea and dilated pupils. The accompanying severe headache often results in reduced feed intake and increased sleep.
After glaucoma, another leading cause of ocular hypotension is uveitis, which can also lead to long-term damage to the optic nerve and thus blindness. The symptoms of both diseases are similar. Most dogs are affected at the age of 4 - 6 years or later.
In our shop we stock, for example, the Icare® TONOVET Tonometer. This device measures intraocular pressure using the rebound measuring principle and is well tolerated by dogs, cats, rabbits, birds and even horses, as it is painless and takes only a few seconds.
Tonometry: Easy, Accurate, Fast
Rebound tonometry and applanation tonometry are among the most practical and easiest procedures for this eye examination. They offer the advantage that the patient does not need to be anaesthetised for the examination, which only takes a few seconds.
Depending on the tonometer used, it does not even require a local anaesthetic of the cornea. Rebound tonometers perform the measurement particularly gently and carefully, so that it is completely painless.
Rebound tonometry can be performed, for example, with the TONOVET Plus Tonometer. At the touch of a button, six measurements are taken in succession.
In the process, a small plastic-tipped probe bounces gently against the cornea. As the probe bounces against the cornea and back into the device, it creates an induction current from which the intraocular pressure is calculated. With the help of a positioning light that shows whether the measurement angle is correct, a precise and simple measurement is ensured.
With applanation tonometry, on the other hand, the cornea should be anaesthetised beforehand, as this is touched by the tip of the tonometer in order to determine precise and accurate values. During the measurement, the rounded tip exerts pressure on the eyeball so that it flattens. The higher the effort required, the higher the intraocular pressure.
The Tono-Pen VET™ is one of the most popular devices for performing this type of measurement. The pen is ready for immediate use thanks to the long-lasting battery and is suitable for all animals. In addition, the Ocu-Film® + Tip Covers, which are placed over the tip of the Tono-Pen VET™ before each use, ensure a low risk of cross-contamination.
Reference Values for Intraocular Pressure (mmHg)
|Uveitis||Normal Range||Borderline case||Glaucoma|
|Dogs||< 10||10 - 20||20- 25||> 25|
|Cats||< 10||10 - 20||20 - 25||> 25|
|Rabbit||< 15||15 - 25||25 - 30||> 30|
|Horse||< 15||15 - 25||25 - 30||> 30|
Order Tonometers & Accessories at Praxisdienst
Whether looking for a particular device, the robust bracket for the iCare TONOVET tonometer, replacement batteries or disposable protective tip covers - veterinarians will find everything they need for professional intraocular pressure measurement in practices and clinics in our online shop.
Do you have any questions about our extensive range? Our friendly customer service will be happy to help you via live chat, phone or email.
Editors: Elisa May, Sam Selzner