VCA Castle Shannon Animal Hospital


Tonometry is the measurement of pressure within the eye (called intraocular pressure). Intraocular pressure (IOP) is the pressure exerted against the outer layers by the eyeball.

Tonometry is performed using an instrument called the tonometer (or tonopen). Generally, the doctor will administer a local anesthetic eye drop, such as proparacaine, to numb the eyeball. This allows the veterinarian to examine the eye without alarming the patient and so that the pet does not feel the minor presence of the tonometry instrument.

Tonometry measures the intraocular pressure to diagnose glaucoma. Glaucoma is caused by the buildup of fluid within the eye. Abnormally high pressure can damage the optic nerve, which in turn, leads to vision loss.

Using tonometry, we can also identify low IOP, which may occur with anterior uveitis (inflammation within the eye). Low IOP is also associated with dehydration.

If you have any questions regarding tonometry, please ask a member of our staff.


Specialty Care

Sometimes sick or injured pets need the care of a veterinary medical specialist. When that happens, VCA specialty hospitals work closely with the general practitioner veterinarians who refer cases to us in order to provide seamless veterinary care to your pet. When your pet is facing any kind of serious illness or injury, our specialty referral hospitals will provide the compassionate and expert care your beloved pet needs.

Our goal is to make sure that when you and your pet are in need that you have access to board certified specialists who are up to date on the very latest developments in their field. In our state of the art hospitals, our specialists also have access to the most sophisticated diagnostic and treatment tools and techniques from ultrasonography and endoscopy to CAT scans and even MRI.

As part of the VCA family, we have over 83 specialty hospitals across the US and Canada which provide referral specialty care, so there may be one near you. Our specialized services include: behavior, cardiology, critical care, dentistry, dermatology, integrative medicine, internal medicine, neurology, oncology, ophthalmology, radiology, rehabilitation, reproduction, and surgery.

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Emergency Care

In case of emergency, please call us immediately at 412-885-2500. We have doctors and technicians on the premises 24/7, including weekends and holidays when you need us most.  Our address is 3610 Library Road, Pittsburgh Pa 15234.